William Haskell
Professor (Research) of Medicine, Emeritus
Medicine - Cardiovascular Medicine
Web page: http://web.stanford.edu/people/whaskell
Academic Appointments
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Emeritus Faculty, Acad Council, Medicine - Cardiovascular Medicine
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Member, Cardiovascular Institute
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Member, Stanford Cancer Institute
Administrative Appointments
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Chair, Scientific Advisory Board, Cooper Institute (1996 - 2008)
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Member, Scientific Advisory Board, Heakth Fitness Corporation (2004 - 2010)
Honors & Awards
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David Bruce Dill Historial Lecture, American College of Sports Medicine Annual Scientific Meeting, (May 1, 2019)
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Honorary Doctorate of Medicine (H.D.M.), Linkoping University, Sweden (1980)
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National Achievement Award, National YMCA (1987)
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National Healthy Fitness Leader Award, JACEES (1990)
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M.D. Silverberg Memorial Lecture, Royal Australian College of Physicians (1990)
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International Achievement Recognition Lecture, South Afriican Sports Medicine Society (1993)
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Joseph Wolffe Memoral Lecture, American College of Sports Medicine (1994)
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Citation Award, American College of Sports Medicine (1995)
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Honorary Member, Order of the Horse Collar Knights, University of Kuopio, Finland (1996)
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Lifetime Achievement Award, American Association of Cardiovascular and Pulmonary Rehablitation (1999)
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Terrance Kavanagh Memorial Lecture, Canadian Cardia Rehabilitation Society (2002)
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Honor Award for Lifetime Achievement, American College of Sports Medicine (2000)
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Distinguished Research in Aging, Council on Aging, AAHPERD (2006)
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Science Honor Award for 2007, President's Council on Physical Fitness and Sports (2007)
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Lifetime Achievement Award, Alumni Association, University of California at Santa Barbara (2007)
Professional Education
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Certificate, State U of New York - Buffalo, Chronic disease Epidemiology (1967)
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Ph.D, U. of Illinois, Exercise Physiology (1965)
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B.S., U of CA @ Santa Barbara, Exercise Science and Biology (1960)
Community and International Work
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Global Physical Activity Guidelines, Geneva
Topic
Public health physical activity recommendations
Partnering Organization(s)
Worl Health Organizatiom
Populations Served
All
Location
International
Ongoing Project
Yes
Opportunities for Student Involvement
No
Current Research and Scholarly Interests
My major research interests and activities over the next several years will focus on the development and evaluation of the objective measurement of physical activity in free-living populations using a variety of sensing devices and mobile phones for data collection and processing. Sensing devices include wireless accelerometers, altimeters, heart rate, skin temperature/heat flux and breathing rate monitors. This research is funded by NIH and is being conducted in collaboration with scientists at MIT. I will continue to direct the Stanford Heart Network, an internet-based patient and health professional support system, with the major mission being to assist community-based CVD prevention/treatment programs implement more effective heart attack and stroke prevention programs. Also, I will continue to collaborate with colleagues on studies promoting energy balance and successful aging.
2023-24 Courses
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Independent Studies (5)
- Directed Reading in Medicine
MED 299 (Aut, Sum) - Early Clinical Experience in Medicine
MED 280 (Aut, Sum) - Graduate Research
MED 399 (Aut, Sum) - Medical Scholars Research
MED 370 (Aut, Sum) - Undergraduate Research
MED 199 (Sum)
- Directed Reading in Medicine
All Publications
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Effect of Structured, Moderate Exercise on Kidney Function Decline in Sedentary Older Adults: An Ancillary Analysis of the LIFE Study Randomized Clinical Trial.
JAMA internal medicine
2022
Abstract
Importance: Observational evidence suggests that higher physical activity is associated with slower kidney function decline; however, to our knowledge, no large trial has evaluated whether activity and exercise can ameliorate kidney function decline in older adults.Objective: To evaluate whether a moderate-intensity exercise intervention can affect the rate of estimated glomerular filtration rate per cystatin C (eGFRCysC) change in older adults.Design, Setting, and Participants: This ancillary analysis of the Lifestyle Interventions and Independence For Elders randomized clinical trial enrolled 1199 community-dwelling, sedentary adults aged 70 to 89 years with mobility limitations and available blood specimens. The original trial was conducted across 8 academic centers in the US from February 2010 through December 2013. Data for this study were analyzed from March 29, 2021, to February 28, 2022.Interventions: Structured, 2-year, partially supervised, moderate-intensity physical activity and exercise (strength, flexibility) intervention compared with a health education control intervention with 2-year follow-up. Physical activity was measured by step count and minutes of moderate-intensity activity using accelerometers.Main Outcomes and Measures: The primary outcome was change in eGFRCysC. Rapid eGFRCysC decline was defined by the high tertile threshold of 6.7%/y.Results: Among the 1199 participants in the analysis, the mean (SD) age was 78.9 (5.2) years, and 800 (66.7%) were women. At baseline, the 2 groups were well balanced by age, comorbidity, and baseline eGFRCysC. The physical activity and exercise intervention resulted in statistically significantly lower decline in eGFRCysC over 2 years compared with the health education arm (mean difference, 0.96 mL/min/1.73 m2; 95% CI, 0.02-1.91 mL/min/1.73 m2) and lower odds of rapid eGFRCysC decline (odds ratio, 0.79; 95% CI, 0.65-0.97).Conclusions and Relevance: Results of this ancillary analysis of a randomized clinical trial showed that when compared with health education, a physical activity and exercise intervention slowed the rate of decline in eGFRCysC among community-dwelling sedentary older adults. Clinicians should consider targeted recommendation of physical activity and moderate-intensity exercise for older adults as a treatment to slow decline in eGFRCysC.Trial Registration: ClinicalTrials.gov Identifier: NCT01072500.
View details for DOI 10.1001/jamainternmed.2022.1449
View details for PubMedID 35499834
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Physical Activity, Adiposity, and Serum Vitamin D Levels in Healthy Women: The Cooper Center Longitudinal Study.
Journal of women's health (2002)
2022
Abstract
Background: Although physical inactivity, obesity, and low serum vitamin D [25-hydroxyvitamin D, 25(OH)D] are common among women, joint associations among these biomarkers are not well-described. Materials and Methods: A total of 7553 healthy women received a comprehensive examination (2006-2018), including self-reported physical activity (PA), body mass index (BMI), waist circumference (WC), waist:height ratio (W:HT), percent body fat (%Fat), and 25(OH)D. Participants were divided into four categories of PA based on current guidelines: <500 (not meeting guidelines), 500-1000 (meeting guidelines), 1001-2500 (>1-2.5 times guidelines), and >2500 (>2.5 times guidelines) metabolic equivalent-minutes/week (MET-Min/wk), and were also classified by clinical cut points for adiposity measures and 25(OH)D. We examined trends of 25(OH)D and adiposity exposures across PA categories and calculated odds ratios (ORs) of vitamin D deficiency across categories of each adiposity exposure. We examined joint associations among PA and adiposity with 25(OH)D. Results: A positive trend was observed for 25(OH)D across PA categories (p<0.001). Compared with normal weight status, the odds for 25(OH)D deficiency were significantly higher for overweight women within adiposity exposures (p for all <0.001). When examining joint associations, 25(OH)D was higher across PA categories within each stratum of BMI, WC, W:HT, and %Fat (p trend <0.007 for all). When examining PA and BMI as continuous variables, OR for vitamin D deficiency were 0.95 (95% confidence interval [CI]: 0.93-0.96) per 250 MET-minutes/week increment in PA, and 1.20 (95% CI: 1.17-1.23) per 2kg/m2 increment in BMI. Conclusions: 25(OH)D levels are positively associated with PA and negatively associated with different measures of adiposity. Higher levels of PA attenuate the association between adiposity and 25(OH)D.
View details for DOI 10.1089/jwh.2021.0402
View details for PubMedID 35352989
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Cardiorespiratory fitness, white blood cell count, and mortality in men and women.
Journal of sport and health science
2021
Abstract
PURPOSE: To examine joint associations of cardiorespiratory fitness (CRF) and white blood cell count (WBC) with mortality outcomes.METHODS: A total of 52,056 apparently healthy adults completed a comprehensive health examination, including a maximal treadmill test and blood chemistry analyses. CRF was categorized as high, moderate, and low by age and sex, while WBC was categorized as sex-specific quartiles.RESULTS: During 17.8 ± 9.5 years (mean ± SD) of follow-up, a total of 4088 deaths occurred. When regressed jointly, we observed significantly decreased all-cause mortality across CRF categories within each quartile of WBC in men. Within WBC Quartile 1, all-cause mortality Hazard Ratios (HR) with 95% confidence interval (95%CI) were 1.0 (referent), 1.29 (95%CI: 1.06‒1.57), and 2.03 (95%CI: 1.42‒2.91) for high, moderate, and low CRF categories, respectively (p trend< 0.001). Similar trends were observed in the remaining three quartiles. With the exception of CVD mortality within Quartile 1 (p trend = 0.74), there were also similar trends across CRF categories within WBC quartiles in men for both cardiovascular disease (CVD) and cancer mortality (p trend < 0.01 for all). For women, there were no significant trends across CRF categories for mortality outcomes within Quartiles 1-3. However, we observed significantly decreased all-cause mortality across CRF categories within WBC Quartile 4 (HR = 1.05 (0.76‒1.44), 1.63 (1.20‒2.21), and 1.87 (1.29‒2.69) for high, moderate, and low CRF, respectively (p trend = 0.002)). Similar trends in women were observed for CVD and cancer mortality within WBC Quartile 4 only.CONCLUSION: There are strong joint associations between CRF, WBC, and all-cause, CVD, and cancer mortality in men; these associations are less consistent in women.
View details for DOI 10.1016/j.jshs.2021.10.005
View details for PubMedID 34740872
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A community-based, multi-level, multi-setting, multi-component intervention to reduce weight gain among low socioeconomic status Latinx children with overweight or obesity: The Stanford GOALS randomised controlled trial.
The lancet. Diabetes & endocrinology
2021
Abstract
BACKGROUND: There are few long-term studies of interventions to reduce in low socioeconomic status children with overweight or obesity. The Stanford GOALS trial evaluated a 3-year, community-based, multi-level, multi-setting, multi-component (MMM) systems intervention, to reduce weight gain among low socioeconomic status, Latinx children with overweight or obesity.METHODS: We did a two-arm, parallel group, randomised, open-label, active placebo-controlled trial with masked assessment over 3 years. Families from low-income, primarily Latinx communities in Northern California, CA, USA, with 7-11-year-old children with overweight or obesity were randomly assigned to a MMM intervention or a Health Education (HE) comparison intervention. The MMM intervention included home environment changes and behavioural counselling, community after school team sports, and reports to primary health-care providers. The primary outcome was child BMI trajectory over three years. Secondary outcomes included one- and two-year changes in BMI. This trial is registered with ClinicalTrials.govNCT01642836.FINDINGS: Between July 13, 2012, and Oct 3, 2013, 241 families were recruited and randomly assigned to MMM (n=120) or HE (n=121). Children's mean age was 9·5 (SD 1·4) years, 134 (56%) were female and 107 (44%) were male, and 236 (98%) were Latinx. 238 (99%) children participated in year 1, 233 (97%) in year 2, and 227 (94%) in year 3 of follow-up assessments. In intention-to-treat analysis, over 3 years, the difference between intervention groups in BMI trajectory was not significant (mean adjusted difference -0·25 [95% CI -0·90 to 0·40] kg/m2; Cohen's d=0.10; p=0·45). Children in the MMM intervention group gained less BMI over 1 year than did children in the HE intervention group (-0·73 [-1·07 to -0·39] kg/m2, d=0.55); the same was true over 2 years (-0·63 [-1·13 to -0·14] kg/m2; d =0.33). No differential adverse events were observed.INTERPRETATION: The MMM intervention did not reduce BMI gain versus HE over 3 years but the effects over 1 and 2 years in this rigorous trial show the promise of this systems intervention approach for reducing weight gain and cardiometabolic risk factors in low socioeconomic status communities.FUNDING: US National Institutes of Health.
View details for DOI 10.1016/S2213-8587(21)00084-X
View details for PubMedID 33933181
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Keeping children healthy during and after COVID-19 pandemic: meeting youth physical activity needs.
BMC public health
2021; 21 (1): 485
Abstract
BACKGROUND: The purpose of this study was to: 1) examine the maintenance of Physical Education and physical activity during the distance learning time, 2) determine the resources educators are utilizing to deliver PE curricula, and 3) understand the challenges experienced by educators during distance learning.METHODS: A survey was sent to a cohort of school-based fitness assessment software users. Respondents were largely school-based individuals including PE teachers (n=1789), school (n=62) and district administrators (n=64), nurses (n=3), and "other" (n=522).RESULTS: Of 2440 respondents, most were from a city or suburb (69.7%), elementary or middle school (72.3%), and had Title 1 status (60.4%), an indicator of low socioeconomic status. Most campuses were closed during the COVID-19 pandemic (97.8%). Of the schools closed during the pandemic, only 2.8% had no prior PE requirements and that increased to 21% during the pandemic. In schools that remained open during the pandemic, 7.7% had no prior PE requirements and this increased to 60.5%. Importantly, 79% of respondents reported that students were either "significantly less" or "somewhat less" physically active during the closure. For closed schools, the most frequently cited challenges included "student access to online learning", "teacher/student communication" and "teacher remote work arrangements". For open schools, the most commonly reported challenges included "social distancing", "access to gymnasium/equipment", and "concern for personal health and wellbeing".CONCLUSION: The COVID-19 pandemic has caused important reductions in PE requirements and time engaged in physical activity. Challenges experienced by teachers were identified for closed and open schools.
View details for DOI 10.1186/s12889-021-10545-x
View details for PubMedID 33706744
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Association of the Omega-3 Index with Incident Prostate Cancer with Updated Meta-Analysis: The Cooper Center Longitudinal Study.
Nutrients
2021; 13 (2)
Abstract
BACKGROUND: The association between long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA) and prostate cancer (PC) remains unclear.METHODS: We compared incident PC rates as a function of the Omega-3 Index [O3I, erythrocyte eicosapentaenoic and docosahexaenoic acids (EPA + DHA)] in 5607 men (40-80 years of age) seen at the Cooper Clinic who were free of PC at baseline. The average follow-up was 5.1 ± 2.8 years until censoring or reporting a new PC diagnosis. Proportional hazards regression was used to model the linear association between baseline O3I and the age-adjusted time to diagnosis. A meta-analysis of n-3 PUFA biomarker-based studies and incident PC was updated with the present findings.RESULTS: A total of 116 cases of incident PC were identified. When O3I was examined as a continuous variable, the age-adjusted hazard ratio (HR) (95% CI) was 0.98 (0.89, 1.07; p = 0.25) for each 1% increment in the O3I. The updated meta-analysis with 10 biomarker-based studies found no significant relationship between EPA or DHA levels and risk for PC.CONCLUSIONS: We find no evidence in this study nor in a meta-analysis of similar studies that consuming n-3 PUFA-rich fish or using fish oil supplements affects the risk of PC.
View details for DOI 10.3390/nu13020384
View details for PubMedID 33530576
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Body mass, cardiorespiratory fitness, and cardiometabolic risk over time: Findings from the Cooper Center Longitudinal Study.
Preventive medicine
2021: 106720
Abstract
Few studies have adequately assessed the simultaneous effects of changes in cardiorespiratory fitness (fitness) and body mass on cardiometabolic risk. Hence, the current study's aims were twofold: (1) To determine whether increases in body mass result in higher cardiometabolic risk after controlling for fitness changes; and (2) To assess whether increases in fitness result in lower cardiometabolic risk after controlling for weight changes. The study consisted of 3534 patients who came for preventive medicine visits ≥4 times over any 10-year period (1979-2019). The primary independent variables were body mass and fitness, and the dependent variable was metabolic syndrome (MetS) and its components. Mixed-effects regression was used to model the relationship between changes in body mass, fitness, and MetS. Results indicate that increasing body mass up to a 10-year period was significantly related to increasing risk of MetS while controlling for changes in fitness. Specifically, a 1-kg increase in body mass was associated with a 17% (OR = 1.17; 95% CI 1.15-1.19) increased odds for MetS, while adjusting for fitness changes. A 1-MET increase in fitness was related to a 23% (OR = 0.77; 95% CI 0.70-0.84) decrease in odds for MetS, while adjusting for body mass changes up to 10 years. Moreover, body mass change was significantly related to changes in all cardiometabolic components of MetS. Fitness change was significantly associated with changes in MetS components. Future interventions should focus concurrently on increasing fitness and on body mass loss (or maintenance) to improve cardiometabolic health.
View details for DOI 10.1016/j.ypmed.2021.106720
View details for PubMedID 34252504
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Higher omega-3 index is associated with more rapid heart rate recovery in healthy men and women.
Prostaglandins, leukotrienes, and essential fatty acids
2020; 163: 102206
Abstract
BACKGROUND: Previous studies have suggested that omega-3 polyunsaturated fatty acids (n-3 PUFA) can favorably influence cardiac autonomic tone. However, data regarding n-3 PUFA status and heart rate recovery (HRR) in healthy adults are sparse.PURPOSE: To examine the association between n-3 PUFA status and HRR.METHODS: Participants included 13,912 patients who underwent a comprehensive examination at the Cooper Clinic, Dallas TX. Fitness was determined from a maximal exercise test. HRR was calculated by subtracting the heart rate at 1, 3, and 5min of an active recovery period from the maximal heart rate. Participants were categorized as having a low (<4%), normal (4-8%) or optimal (>8%) Omega-3 Index (O3I) (i.e., erythrocyte levels of eicosapentaenoic and docosahexaenoic acids). Multiple linear regression was used to model the association between O3I and HRR adjusting for age, maximal METs, body mass index, and smoking by sex.RESULTS: Higher categories of O3I were associated with greater HRR at 1min (men: 23.7, 23.9, 24.6 beats/min; women: 23.9, 24.6, 25.9 and 3min (men: 52.4, 52.9, 53.6 beats/min; women: 51.9, 53.4, 54.6), p trend <0.01 for all. Corresponding HRR at 5min were (men: 60.0, 60.2, 60.7 beats/min, p trend=0.09; women: 59.4, 60.8, 61.6, p trend <0.001). The HRR gradients across O3I categories were steeper in women than men at 1, 3, and 5min (p<0.03 for all sex x O3I category interactions with HRR).CONCLUSIONS: A direct relationship between HRR and O3I values was observed in both men and women, with a steeper gradient in women. These findings suggest a potential cardioprotective mechanism for n-3 PUFA.
View details for DOI 10.1016/j.plefa.2020.102206
View details for PubMedID 33227647
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Estimating energy expenditure of head-hauling water and grain grinding from heart rate monitor measurements in northern Mozambique.
Public health nutrition
2020: 1–12
Abstract
OBJECTIVE: Even though sub-Saharan African women spend millions of person-hours per day fetching water and pounding grain, to date, few studies have rigorously assessed the energy expenditure costs of such domestic activities. As a result, most analyses that consider head-hauling water or hand pounding of grain with a mortar and pestle (pilao use) employ energy expenditure values derived from limited research. The current paper compares estimated energy expenditure values from heart rate monitors v. indirect calorimetry in order to understand some of the limitations with using such monitors to measure domestic activities.DESIGN: This confirmation study estimates the metabolic equivalent of task (MET) value for head-hauling water and hand-pounding grain using both indirect calorimetry and heart rate monitors under laboratory conditions.SETTING: The study was conducted in Nampula, Mozambique.PARTICIPANTS: Forty university students in Nampula city who recurrently engaged in water-fetching activities.RESULTS: Including all participants, the mean MET value for head hauling 20 litres (20·5 kg, including container) of water (2·7 km/h, 0 % slope) was 4·3 (sd 0·9) and 3·7 (sd 1·2) for pilao use. Estimated energy expenditure predictions from a mixed model were found to correlate with observed energy expenditure (r2 0·68, r 0·82). Re-estimating the model with pilao use data excluded improved the fit substantially (r2 0·83, r 0·91).CONCLUSIONS: The current study finds that heart rate monitors are suitable instruments for providing accurate quantification of energy expenditure for some domestic activities, such as head-hauling water, but are not appropriate for quantifying expenditures of other activities, such as hand-pounding grain.
View details for DOI 10.1017/S1368980020001019
View details for PubMedID 32611478
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Cardiorespiratory Fitness, Body-Mass Index, and Markers of Insulin Resistance in Apparently Healthy Women and Men.
The American journal of medicine
2020
Abstract
BACKGROUND: Insulin resistance may be present in healthy adults and is associated poor health outcomes. Obesity is a risk factor for insulin resistance, but most obese adults do not have insulin resistance. Fitness may be protective, but the association between fitness, weight, and insulin resistance has not been studied in a large population of healthy adults.METHODS: A cross-sectional analysis of cardiorespiratory fitness, body-mass index, and markers of insulin resistance was performed. Study participants were enrolled at the Cooper Clinic (Dallas, Texas). The analysis included 19,263 women and 48,433 men with no history of diabetes or cardiovascular disease. Cardiorespiratory fitness was measured using exercise treadmill testing. Impaired fasting glucose (100-125 mg/dL) and elevated fasting triglycerides (≥150 mg/dL) were used as a markers of insulin resistance.RESULTS: Among normal weight individuals, poor fitness was associated with a 2.2 (1.4-3.6; p=0.001) fold higher odds of insulin resistance in women and a 2.8 (2.1-3.6; p<0.001) fold higher odds in men. The impact of fitness remained significant for overweight and obese individuals, with the highest risk group being the unfit obese. Among obese women, the odds ratio for insulin resistance was 11.0 (8.7-13.9; p<0.001) for fit and 20.3 (15.5-26.5; p<0.001) for unfit women. Among obese men, the odds ratio for insulin resistance was 7.4 (6.7-8.2; p<0.001) for fit and 12.9 (11.4-14.6; p<0.001) for unfit men.CONCLUSION: Independent of weight, poor fitness is associated with risk of insulin resistance. Obese individuals, particularly women, may benefit from the greatest absolute risk reduction by achieving moderate fitness.
View details for DOI 10.1016/j.amjmed.2019.11.031
View details for PubMedID 31926863
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Relevance of Fitness to Mortality Risk in Men Receiving Contemporary Medical Care.
Journal of the American College of Cardiology
2020; 75 (13): 1538–47
Abstract
An inverse association between cardiorespiratory fitness and mortality was robustly demonstrated 3 decades ago.The purpose of this study was to determine whether significant advances in disease prevention, detection, and treatment since that time have modified this association.A total of 47,862 men completed baseline examinations, including a maximal treadmill test. Cohort 1 (n = 24,475) was examined during 1971 to 1991 and followed for mortality through 1992. Cohort 2 (n = 23,387) was examined during 1992 to 2013 with follow-up through 2014. Men were categorized as low fit, moderate fit, or high fit using Cooper Clinic normative data. Hazard ratios (HRs) for all-cause, cardiovascular disease, and cancer mortality were determined across fitness categories in the 2 cohorts.A significant inverse trend between fitness categories and all-cause (HR: 1.0, 0.60, and 0.53 in cohort 1 and HR: 1.0, 0.76, and 0.52 in cohort 2) and cardiovascular disease mortality (HR: 1.0, 0.55, and 0.43 in cohort 1 and HR: 1.0, 0.84, and 0.52 in cohort 2) was observed (p trend <0.001 for all). The trend across fitness categories and cancer mortality was significant for cohort 1 (HR: 1.0, 0.62, and 0.48; p < 0.001), but not for cohort 2 (HR: 1.0, 1.08, and 0.74; p = 0.19). HRs for all-cause mortality were 0.86 (95% confidence interval: 0.82 to 0.90) and 0.87 (95% confidence interval: 0.83 to 0.91) per 1-MET increment in fitness for cohorts 1 and 2, respectively (p < 0.001 for both). Similar values were seen for cardiovascular disease and cancer mortality.Despite significant advances in disease prevention, detection, and treatment since fitness was first shown to be associated with mortality, the inverse association between fitness and mortality remains consistent in a contemporary cohort of men.
View details for DOI 10.1016/j.jacc.2020.01.049
View details for PubMedID 32241369
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Functional Movement Screening Performance and Association With Key Health Markers in Older Adults.
Journal of strength and conditioning research
2019
Abstract
Farrell, SW, Pavlovic, A, Barlow, CE, Leonard, D, DeFina, JR, Willis, BL, DeFina, LF, and Haskell, WL. Functional movement screening performance and association with key health markers in older adults. J Strength Cond Res XX(X): 000-000, 2019-We examined Functional Movement Screening (FMS) performance and associations with key health markers among adults aged 55 years or older. Apparently healthy men (n = 425) and women (n = 158) completed a preventive medical examination between 2013 and 2018. Subjects were grouped by age and sex to determine mean scores for individual FMS items as well as total FMS score. We examined partial correlations between total FMS score and key health markers. We computed odds ratios (ORs) for having a total FMS score ≤14. The mean FMS scores for men and women were 11.7 ± 2.8 and 11.9 ± 2.3, respectively. Several differences were found between men who participated in FMS (takers) compared with FMS nontakers, whereas women FMS takers were generally similar to women FMS nontakers. After controlling for age, sex, and smoking, FMS scores were directly associated with physical activity (PA), cardiorespiratory fitness, frequency of resistance training, serum vitamin D, omega-3 index, low-density lipoprotein, and high-density lipoprotein (HDL)-cholesterol, and were inversely associated with body mass index (BMI), waist circumference (WC), blood glucose, HbA1c, and metabolic syndrome (p ≤ 0.02 for each). Adjusted OR for scoring ≤14 was significantly greater for those who were BMI and WC-obese, those with metabolic syndrome, those with low HDL-cholesterol, and those not meeting current PA guidelines. This study provides characteristics and mean values for FMS in a large older population and demonstrates that FMS performance is associated with key health markers. Prospective studies of older adults are needed to determine the utility of FMS in predicting future musculoskeletal injury and other chronic disease-related health outcomes.
View details for DOI 10.1519/JSC.0000000000003273
View details for PubMedID 31895281
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Impact of Baseline Fatigue on a Physical Activity Intervention to Prevent Mobility Disability.
Journal of the American Geriatrics Society
2019
Abstract
OBJECTIVES: Our aim was to examine the impacts of baseline fatigue on the effectiveness of a physical activity (PA) intervention to prevent major mobility disability (MMD) and persistent major mobility disability (PMMD) in participants from the Lifestyle Interventions and Independence for Elders (LIFE) study.DESIGN: Prospective cohort of individuals aged 65years or older undergoing structured PA intervention or health education (HE) for a mean of 2.6years.SETTING: LIFE was a multicenter eight-site randomized trial that compared the efficacy of a structured PA intervention with an HE program in reducing the incidence of MMD.PARTICIPANTS: Study participants (N=1591) at baseline were 78.9±5.2years of age, with low PA and at risk for mobility impairment.MEASUREMENTS: Self-reported fatigue was assessed using the modified trait version of the Exercise-Induced Feelings Inventory, a six-question scale rating energy levels in the past week. Responses ranged from 0 (none of the time) to 5 (all of the time). Total score was calculated by averaging across questions; baseline fatigue was based on the median split: 2 or higher=more fatigue (N=856) and lower than 2=less fatigue (N=735). Participants performed a usual-paced 400-m walk every 6months. We defined incident MMD as the inability to walk 400-m at follow-up visits; PMMD was defined as two consecutive walk failures. Cox proportional hazard models quantified the risk of MMD and PMMD in PA vs HE stratified by baseline fatigue adjusted for covariates.RESULTS: Among those with higher baseline fatigue, PA participants had a 29% and 40% lower risk of MMD and PMMD, respectively, over the trial compared with HE (hazard ratio [HR] for MMD=.71; 95% confidence interval [CI] =.57-.90; P=.004) and PMMD (HR=.60; 95% CI=.44-.82; P=.001). For those with lower baseline fatigue, no group differences in MMD (P=.36) or PMMD (P=.82) were found. Results of baseline fatigue by intervention interaction was MMD (P=.18) and PMMD (P=.05).CONCLUSION: A long-term moderate intensity PA intervention was particularly effective at preserving mobility in older adults with higher levels of baseline fatigue.
View details for DOI 10.1111/jgs.16274
View details for PubMedID 31867713
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Guidelines for Physical Activity and Health in the United States: Evolution over 50 Years
ACSMS HEALTH & FITNESS JOURNAL
2019; 23 (5): 5–8
View details for DOI 10.1249/FIT.0000000000000506
View details for Web of Science ID 000483686000001
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Short- and Long-term Effects of a Mobile Phone App in Conjunction With Brief In-Person Counseling on Physical Activity Among Physically Inactive Women: The mPED Randomized Clinical Trial.
JAMA network open
2019; 2 (5): e194281
Abstract
Importance: Mobile phone applications (apps) and activity trackers allow researchers to remotely deliver an intervention and monitor physical activity but have not been rigorously evaluated for longer periods.Objective: To determine whether a mobile phone-based physical activity education app, in conjunction with brief in-person counseling, increases and then maintains levels of physical activity.Design, Setting, and Participants: In this parallel randomized clinical trial, community-dwelling physically inactive women recruited between May 2011 and April 2014 were randomized in equal proportions into the control (n=69), regular (n=71), and plus (n=70) groups. Data were analyzed using intention to treat from September 16, 2016, through June 30, 2018.Interventions: The regular and plus groups were instructed to use the app on their mobile phone and an accelerometer every day for 3 months and attend brief in-person counseling. During the 6-month maintenance period, the plus group continued to use the app and accelerometer, while the regular group stopped using the app but continued using the accelerometer. The control group used the accelerometer throughout.Main Outcomes and Measures: The primary and secondary outcomes were daily accelerometer-measured total steps and time spent in moderate to vigorous physical activity (MVPA).Results: The 210 participants had a mean (SD) age of 52.4 (11.0) years. At baseline, the mean (SD) daily total steps by accelerometer in the control, regular, and plus groups were 5384 (2920), 5063 (2526), and 5837 (3235), respectively. During the 3-month intervention period, daily steps and MVPA increased in the combined regular and plus groups compared with the control group (between-group differences, 2060 steps per day; 95% CI, 1296-2825 steps per day; P<.001 and 18.2 min/d MVPA; 95% CI, 10.9-25.4 min/d MVPA; P<.001). During the subsequent 6-month maintenance period, mean activity level remained higher in the combined plus and regular groups than among controls (between-group difference, 1360 steps per day; 95% CI, 694-2026 steps per day; P<.001), but trends in total daily steps and MVPA were similar in the plus and regular groups.Conclusions and Relevance: In this trial, the intervention groups substantially increased their physical activity. However, use of both the app and accelerometer for an additional 6 months after the initial 3-month intervention did not help to maintain increases in physical activity compared with continued use of the accelerometer alone.Trial Registration: ClinicalTrials.gov identifier: NCT01280812.
View details for DOI 10.1001/jamanetworkopen.2019.4281
View details for PubMedID 31125101
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Physical activity, sleep and cardiovascular health data for 50,000 individuals from the MyHeart Counts Study
SCIENTIFIC DATA
2019; 6
View details for DOI 10.1038/s41597-019-0016-7
View details for Web of Science ID 000464198800001
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Physical activity, sleep and cardiovascular health data for 50,000 individuals from the MyHeart Counts Study.
Scientific data
2019; 6 (1): 24
Abstract
Studies have established the importance of physical activity and fitness for long-term cardiovascular health, yet limited data exist on the association between objective, real-world large-scale physical activity patterns, fitness, sleep, and cardiovascular health primarily due to difficulties in collecting such datasets. We present data from the MyHeart Counts Cardiovascular Health Study, wherein participants contributed data via an iPhone application built using Apple's ResearchKit framework and consented to make this data available freely for further research applications. In this smartphone-based study of cardiovascular health, participants recorded daily physical activity, completed health questionnaires, and performed a 6-minute walk fitness test. Data from English-speaking participants aged 18 years or older with a US-registered iPhone who agreed to share their data broadly and who enrolled between the study's launch and the time of the data freeze for this data release (March 10 2015-October 28 2015) are now available for further research. It is anticipated that releasing this large-scale collection of real-world physical activity, fitness, sleep, and cardiovascular health data will enable the research community to work collaboratively towards improving our understanding of the relationship between cardiovascular indicators, lifestyle, and overall health, as well as inform mobile health research best practices.
View details for PubMedID 30975992
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The 24-Hour Activity Cycle: A New Paradigm for Physical Activity
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2019; 51 (3): 454–64
View details for DOI 10.1249/MSS.0000000000001811
View details for Web of Science ID 000459886200009
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Association of All-Cause and Cardiovascular Mortality With High Levels of Physical Activity and Concurrent Coronary Artery Calcification.
JAMA cardiology
2019
Abstract
Importance: Few data are available to guide clinical recommendations for individuals with high levels of physical activity in the presence of clinically significant coronary artery calcification (CAC).Objective: To assess the association among high levels of physical activity, prevalent CAC, and subsequent mortality risk.Design, Setting, and Participants: The Cooper Center Longitudinal Study is a prospective observational study of patients from the Cooper Clinic, a preventive medicine facility. The present study included participants seen from January 13, 1998, through December 30, 2013, with mortality follow-up through December 31, 2014. A total of 21 758 generally healthy men without prevalent cardiovascular disease (CVD) were included if they reported their physical activity level and underwent CAC scanning. Data were analyzed from September 26, 2017, through May 2, 2018.Exposures: Self-reported physical activity was categorized into at least 3000 (n=1561), 1500 to 2999 (n=3750), and less than 1500 (n=16 447) metabolic equivalent of task (MET)-minutes/week (min/wk). The CAC scores were categorized into at least 100 (n=5314) and less than 100 (n=16 444) Agatston units (AU).Main Outcomes and Measures: All-cause and CVD mortality collected from the National Death Index Plus.Results: Among the 21 758 male participants, baseline mean (SD) age was 51.7(8.4) years. Men with at least 3000 MET-min/wk were more likely to have prevalent CAC of at least 100 AU (relative risk, 1.11; 95% CI, 1.03-1.20) compared with those accumulating less physical activity. In the group with physical activity of at least 3000 MET-min/wk and CAC of at least 100 AU, mean (SD) CAC level was 807 (1120) AU. After a mean (SD) follow-up of 10.4 (4.3) years, 759 all-cause and 180 CVD deaths occurred, including 40 all-cause and 10 CVD deaths among those with physical activity of at least 3000 MET-min/wk. Men with CAC of less than 100 AU and physical activity of at least 3000 MET-min/wk were about half as likely to die compared with men with less than 1500 MET-min/wk (hazard ratio [HR], 0.52; 95% CI, 0.29-0.91). In the group with CAC of at least 100 AU, men with at least 3000 MET-min/wk did not have a significant increase in all-cause mortality (HR, 0.77; 95% CI, 0.52-1.15) when compared with men with physical activity of less than 1500 MET-min/wk. In the least active men, those with CAC of at least 100 AU were twice as likely to die of CVD compared with those with CAC of less than 100 AU (HR, 1.93; 95% CI, 1.34-2.78).Conclusions and Relevance: This study suggests there is evidence that high levels of physical activity (≥3000 MET-min/wk) are associated with prevalent CAC but are not associated with increased all-cause or CVD mortality after a decade of follow-up, even in the presence of clinically significant CAC levels.
View details for PubMedID 30698608
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Physical Activity, All-Cause and Cardiovascular Mortality, and Cardiovascular Disease.
Medicine and science in sports and exercise
2019; 51 (6): 1270–81
Abstract
Conduct a systematic umbrella review to evaluate the relationship of physical activity (PA) with all-cause mortality, cardiovascular mortality, and incident cardiovascular disease (CVD); to evaluate the shape of the dose-response relationships; and to evaluate these relationships relative to the 2008 Physical Activity Guidelines Advisory Committee Report.Primary search encompassing 2006 to March, 2018 for existing systematic reviews, meta-analyses, and pooled analyses reporting on these relationships. Graded the strength of evidence using a matrix developed for the Physical Activity Guidelines Advisory Committee.The association of self-reported moderate-to-vigorous physical activity (MVPA) on all-cause mortality, CVD mortality, and atherosclerotic CVD-including incident coronary heart disease, ischemic stroke and heart failure-are very similar. Increasing MVPA to guidelines amounts in the inactive US population has the potential to have an important and substantial positive impact on these outcomes in the adult population. The following points are clear: the associations of PA with beneficial health outcomes begin when adopting very modest (one-third of guidelines) amounts; any MVPA is better than none; meeting the 2008 PA guidelines reduces mortality and CVD risk to about 75% of the maximal benefit obtained by physical activity alone; PA amounts beyond guidelines recommendations amount reduces risk even more, but greater amounts of PA are required to obtain smaller health benefits; and there is no evidence of excess risk over the maximal effect observed at about three to five times the amounts associated with current guidelines. When PA is quantified in terms of energy expenditure (MET·h·wk), these relationships hold for walking, running, and biking.To avoid the risks associated with premature mortality and the development of ischemic heart disease, ischemic stroke, and all-cause heart failure, all adults should strive to reach the 2008 Physical Activity Guidelines for Americans.
View details for DOI 10.1249/MSS.0000000000001939
View details for PubMedID 31095084
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Cardiorespiratory Fitness, Different Measures of Adiposity, and Cardiovascular Disease Mortality Risk in Women.
Journal of women's health (2002)
2019
Abstract
Background: Associations among cardiorespiratory fitness (CRF), different adiposity exposures, and cardiovascular disease (CVD) mortality in women are not well defined. Materials and Methods: A total of 19,838 women completed a baseline examination between 1971 and 2013. Measures included body mass index (BMI), waist circumference (WC), waist-to-height (W:HT) ratio, skinfold-derived percent body fat (% Fat), and CRF estimated from a maximal treadmill test. CRF categories were low (quintile 1), moderate (quintiles 2-3), and high (quintiles 4-5); standard cut points were used for adiposity exposures. Hazard ratios (HRs) were estimated using Cox regression. Results: During a mean follow-up period of 19.2 ± 10.3 years, 391 cardiovascular deaths occurred. HRs (95% confidence interval) for CVD in moderate and low CRF groups, using high CRF as the referent, were 1.87 (1.46-2.38) and 2.54 (1.93-3.35), respectively (p trend <0.001). HRs of obese women within each adiposity exposure were higher when compared with normal-weight women (p ≤ 0.03). Joint associations of CRF × adiposity showed a positive trend in CVD mortality across decreasing categories of CRF within each category of W:HT and % Fat, as well as within the normal and overweight BMI categories and the normal WC category (p ≤ 0.03 for each). Conclusion: Higher levels of CRF are associated with lower CVD mortality risk in women, and predict lower risk of CVD mortality in normal-weight women and in obese women. Using different measures of adiposity to predict CVD mortality risk in women may be misleading unless CRF is taken into account. These results support the American Heart Association (AHA) recommendation for including CRF as a clinical vital sign.
View details for DOI 10.1089/jwh.2019.7793
View details for PubMedID 31532335
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High-Intensity Interval Training for Cardiometabolic Disease Prevention.
Medicine and science in sports and exercise
2019; 51 (6): 1220–26
Abstract
The 2018 Physical Activity Guidelines Advisory Committee systematically searched existing literature reviews to assess the relationship between high-intensity interval training (HIIT) and reduction in cardiometabolic disease risk.Duplicate independent screenings of 260 articles identified from PubMed®, Cochrane Library, and CINAHL databases yielded suitable data from one systematic review and two meta-analyses. Search terms included a combination of "high intensity" "physical activity/exercise" and "interval training" and outcome-specific terms. The quality of the included reviews was assessed using a tailored version of the AMSTARExBP report on quality. Exposure Subcommittee members graded scientific evidence strength based on a five-criteria rubric and assigned one of four grades: strong, moderate, limited, or not assignable.Moderate evidence indicates that HIIT can improve insulin sensitivity, blood pressure, and body composition in adults with group mean ages ranging from ~20 to ~77 yr. These HIIT-induced improvements in cardiometabolic disease risk factors are comparable with those resulting from moderate-intensity continuous training, and they are more likely to occur in adults at higher risk of cardiovascular disease and diabetes than in healthy adults. Moderate evidence also indicates that adults with overweight or obesity classification are more responsive than adults with normal weight to HIIT-related improvements in insulin sensitivity, blood pressure, and body composition. Insufficient evidence was available to determine whether a dose-response relationship exists between the quantity of HIIT performed and several risk factors for cardiovascular disease and diabetes, or whether the effects of HIIT on cardiometabolic disease risk factors are influenced by age, sex, race/ethnicity, or socioeconomic status.HIIT by adults, especially those with overweight and obesity classification, can improve insulin sensitivity, blood pressure, and body composition, comparable with those resulting from moderate-intensity continuous training.
View details for DOI 10.1249/MSS.0000000000001934
View details for PubMedID 31095079
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Cardiorespiratory fitness, different measures of adiposity, and serum vitamin D levels in African-American adults.
Journal of investigative medicine : the official publication of the American Federation for Clinical Research
2019
Abstract
We examined the associations among cardiorespiratory fitness (CRF), adiposity, and serum 25-hydroxyvitamin D [25(OH)D) levels in African-American (AA) adults. 468 AA patients from the Cooper Clinic in Dallas, TX were examined between 2007 and 2018. Measures included body mass index (BMI), waist circumference (WC), percent body fat (%fat) via skinfolds, CRF via a maximal treadmill test, and 25(OH)D. Participants were classified by CRF based on age and sex, as well as by clinical categories of adiposity exposures and 25(OH)D. We examined trends of 25(OH)D across CRF and adiposity categories. We calculated OR with 95% CIs for 25(OH)D deficiency across categories of CRF and adiposity measures. We observed a significant positive trend for CRF (p=0.01) and a significant inverse trend for BMI (p=0.005) across ordered 25(OH)D categories. Adjusted mean 25(OH)D levels were higher across ordered CRF categories (p=0.03), and lower across ordered categories of BMI (p=0.02), WC (p=0.03) and %fat (p=0.04). When grouped into categories of fit and unfit (upper 80% and lower 20% of the CRF distribution, respectively), OR for vitamin D deficiency was significantly lower in fit compared with unfit men and women (OR=0.55, 95% CI: 0.35-0.87, p=0.01). Compared with normal weight BMI (referent), ORs for 25(OH)D deficiency were significantly higher for BMI-obese subjects (OR=1.70, 95% CI: 1.00-2.87, p=0.04). 25(OH)D levels are positively associated with CRF and negatively associated with different measures of adiposity in AA men and women. Because of the study design, causal inferences cannot be made and future prospective studies are needed.
View details for DOI 10.1136/jim-2019-001071
View details for PubMedID 31371389
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Effect of Hospitalizations on Physical Activity Patterns in Mobility-Limited Older Adults.
Journal of the American Geriatrics Society
2018
Abstract
OBJECTIVES: To evaluate the effect of hospitalizations on patterns of sedentary and physical activity time in mobility-limited older adults randomized to structured physical activity or health education.DESIGN: Secondary analysis of investigator-blinded, parallel-group, randomized trial conducted at 8 U.S. centers between February 2010 and December 2013.PARTICIPANTS: Sedentary men and women aged 70 to 89 at baseline who wore a hip-fitted accelerometer 7 consecutive days at baseline and 6, 12, and 24 months after randomization (N=1,341).MEASUREMENTS: Participants were randomized to a physical activity (PA; n = 669) intervention that included aerobic, resistance, and flexibility training or to a health education (HE; n = 672) intervention that consisted of workshops on older adult health and light upper-extremity stretching. Accelerometer patterns were characterized as bouts of sedentary (<100 counts/min; ≥1, ≥10, ≥30, ≥60 minute lengths) and activity (≥100 counts/min; ≥1, ≥2, ≥5, ≥10 minute lengths) time. Each participant was categorized as having 0, 1 to 3, or 4 or more cumulative hospital days before each accelerometer assessment.RESULTS: Hospitalization increased sedentary time similarly in both intervention groups (8 min/d for 1-3 cumulative hospital days and 16 min/d for ≥4 cumulative hospital days). Hospitalization was also associated with less physical activity time across all bouts of less than 10 minutes (≥1: -7 min/d for 1-3 cumulative hospital days, -16 min/d for ≥4 cumulative hospital days; ≥2: -5 min/d for 1-3 cumulative hospital days, -11 min/d for ≥4 cumulative hospital days; ≥5: -3 min/d for 1-3 cumulative hospital days, -4 min/d for ≥4 cumulative hospital days). There was no evidence of recovery to prehospitalization levels (time effect p >.41). PA participants had less sedentary time in bouts of less than 30 minutes than HE participants (-8 to -10 min/d) and more total activity (+3 to +6 min/d), although hospital-related changes were similar between the intervention groups (interaction effect p >.26).CONCLUSION: Participating in a PA intervention before hospitalization had expected benefits, but participants remained susceptible to hospitalization's detrimental effects on their daily activity levels. There was no evidence of better activity recovery after hospitalization.
View details for PubMedID 30452084
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The 24-Hour Activity Cycle: A New Paradigm for Physical Activity.
Medicine and science in sports and exercise
2018
Abstract
The physiologic mechanisms by which the four activities of sleep, sedentary behavior, light-intensity physical activity (LIPA), and moderate-to-vigorous physical activity (MVPA) affect health are related, but these relationships have not been well explored in adults. Research studies have commonly evaluated how time spent in one activity affects health. Because one can only increase time in one activity by decreasing time in another, such studies cannot determine the extent that a health benefit is due to one activity versus due to reallocating time among the other activities. For example, interventions to improve sleep possibly also increase time spent in MVPA. If so, the overall effect of such interventions on risk of premature mortality is due to both more MVPA and better sleep. Further, the potential for interaction between activities to affect health outcomes is largely unexplored. For example, is there a threshold of MVPA minutes per day, above which adverse health effects of sedentary behavior are eliminated? This paper considers the 24-Hour Activity Cycle (24-HAC) model as a paradigm for exploring inter-relatedness of health effects of the four activities. It discusses how to measure time spent in each of the four activities, as well as the analytical and statistical challenges in analyzing data based upon the model, including the inevitable challenge of confounding among activities. The potential usefulness of this model is described by reviewing selected research findings that aided in the creation of the model and discussing future applications of the 24-HAC model.
View details for PubMedID 30339658
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Relation of Coronary Artery Diameters With Cardiorespiratory Fitness
AMERICAN JOURNAL OF CARDIOLOGY
2018; 121 (9): 1065–71
Abstract
Cardiorespiratory fitness is associated with reduced cardiovascular morbidity and mortality when adjusted for traditional risk factors. Mechanisms by which fitness reduces risk have been studied but remain incompletely understood. We hypothesize that higher fitness is associated with larger coronary artery diameters independent of its effect on traditional risk factors. Two independent measurements of the proximal diameters of the left main, left anterior descending, left circumflex, and right coronary arteries were obtained from gated multidetector computed tomography scans in 500 men from the Cooper Center Longitudinal Study (CCLS). Men with coronary artery calcium scores ≥10 were excluded. Fitness was measured with a maximal exercise treadmill test and reported by quintiles and as a function of METs. We then evaluated the relation between coronary artery diameters and fitness using mixed effect regression models. Higher fitness was associated with larger coronary artery diameters after adjustment for body surface area, smoking status, low-density lipoprotein and high-density lipoprotein cholesterol, resting systolic blood pressure, and serum glucose. When examined continuously, each MET increase in fitness was associated with a mean 0.03 ± 0.01 mm larger diameter of the left main, a 0.04 ± 0.01 mm larger diameter of the left anterior descending, a 0.05 ± 0.01 mm larger diameter of the left circumflex, and a 0.07 ± 0.01 mm larger diameter of the right coronary artery (p = 0.002). This correlation between fitness and coronary artery diameters was most prominent for fitness levels above 10 METs. In conclusion, higher fitness is associated with larger coronary artery diameters.
View details for PubMedID 29502792
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Accumulation of Moderate-to-Vigorous Physical Activity and All-Cause Mortality
JOURNAL OF THE AMERICAN HEART ASSOCIATION
2018; 7 (6)
View details for PubMedID 29567765
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Objectively Measured Baseline Physical Activity Patterns in Women in the mPED Trial: Cluster Analysis.
JMIR public health and surveillance
2018; 4 (1): e10
Abstract
Determining patterns of physical activity throughout the day could assist in developing more personalized interventions or physical activity guidelines in general and, in particular, for women who are less likely to be physically active than men.The aims of this report are to identify clusters of women based on accelerometer-measured baseline raw metabolic equivalent of task (MET) values and a normalized version of the METs ≥3 data, and to compare sociodemographic and cardiometabolic risks among these identified clusters.A total of 215 women who were enrolled in the Mobile Phone Based Physical Activity Education (mPED) trial and wore an accelerometer for at least 8 hours per day for the 7 days prior to the randomization visit were analyzed. The k-means clustering method and the Lloyd algorithm were used on the data. We used the elbow method to choose the number of clusters, looking at the percentage of variance explained as a function of the number of clusters.The results of the k-means cluster analyses of raw METs revealed three different clusters. The unengaged group (n=102) had the highest depressive symptoms score compared with the afternoon engaged (n=65) and morning engaged (n=48) groups (overall P<.001). Based on a normalized version of the METs ≥3 data, the moderate-to-vigorous physical activity (MVPA) evening peak group (n=108) had a higher body mass index (P=.03), waist circumference (P=.02), and hip circumference (P=.03) than the MVPA noon peak group (n=61).Categorizing physically inactive individuals into more specific activity patterns could aid in creating timing, frequency, duration, and intensity of physical activity interventions for women. Further research is needed to confirm these cluster groups using a large national dataset.ClinicalTrials.gov NCT01280812; https://clinicaltrials.gov/ct2/show/NCT01280812 (Archived by WebCite at http://www.webcitation.org/6vVyLzwft).
View details for DOI 10.2196/publichealth.9138
View details for PubMedID 29391341
View details for PubMedCentralID PMC5814604
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Dietary Patterns and Long-Term Survival: A Retrospective Study of Healthy Primary Care Patients
AMERICAN JOURNAL OF MEDICINE
2018; 131 (1): 48–55
View details for DOI 10.1016/j.amjmed.2017.08.010
View details for Web of Science ID 000417605300030
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Association of Educational Attainment and Cardiovascular Risk in Hispanic Individuals: Findings From the Cooper Center Longitudinal Study.
JAMA cardiology
2018
Abstract
Hispanic individuals are the fastest growing ethnic group in the United States and face lower socioeconomic status compared with non-Hispanic white (NHW) individuals. However, Hispanic individuals tend to experience better health outcomes than expected, a phenomenon known as the Hispanic paradox. Little is known about how higher socioeconomic status is associated with Hispanic cardiovascular risk factor burden and outcomes.To determine cardiovascular risk and outcomes among highly educated Hispanic vs NHW individuals in a preventive medicine clinic.Retrospective cohort analysis of participants from the Cooper Center Longitudinal Study who underwent preventive medical examinations at the Cooper Clinic in Dallas, Texas, from October 1972 to November 2017. Analysis began April 2018.Ethnicity, self-defined as Hispanic or NHW.Prevalence of major metabolic risk factors and cardiorespiratory fitness were compared, as were changes among participants with at least 2 visits. Ethnic differences adjusted for age, examination year, and educational attainment were estimated using regression models. Age-matched comparisons of coronary artery calcium scores were performed. All-cause mortality was summarized using the Kaplan-Meier method.This study included 1351 Hispanic and 43 736 NHW participants aged 20 to 80 years, body mass index between 18.5 and 50.0, and were not missing key cardiometabolic or fitness variables. Both Hispanic and NHW participants had high educational attainment, with a mean of more than 15 years of total education. Hispanic women and men had a higher prevalence of metabolic syndrome (71 of 518 [13.1%] vs 1477 of 13 732 [10.8%] for women and 255 of 833 [30.6%] vs 7902 of 30 004 [26.3%] for men, respectively). Although Hispanic individuals were twice as likely to have diabetes, there was no difference in calculated 10-year atherosclerotic cardiovascular disease risk scores by ethnicity. Both Hispanic and NWH individuals experienced a statistically significant worsening in cardiometabolic parameters during follow-up, although this was not statistically significantly different between groups. In age-matched analyses, there were no significant differences in the prevalence of coronary artery calcium scores between Hispanic and NWH individuals. During a mean (SD) follow-up of 12.9 (7.5) years, there was no difference in mortality between Hispanic and NHW individuals.Hispanic and NHW men and women with high educational attainment had similar atherosclerotic cardiovascular disease risk, subclinical coronary atherosclerosis, and mortality during follow-up. These findings do not support the Hispanic paradox in a highly educated Hispanic population.
View details for PubMedID 30566183
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Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study
JOURNAL OF THE AMERICAN HEART ASSOCIATION
2017; 6 (12)
Abstract
Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study.Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates.Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data.URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500.
View details for PubMedID 29197830
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Moderate to High Levels of Cardiorespiratory Fitness Attenuate the Effects of Triglyceride to High-Density Lipoprotein Cholesterol Ratio on Coronary Heart Disease Mortality in Men.
Mayo Clinic proceedings
2017; 92 (12): 1763-1771
Abstract
To examine the prospective relationships among cardiorespiratory fitness (CRF), fasting blood triglyceride to high density lipoprotein cholesterol ratio (TG:HDL-C), and coronary heart disease (CHD) mortality in men.A total of 40,269 men received a comprehensive baseline clinical examination between January 1, 1978, and December 31, 2010. Their CRF was determined from a maximal treadmill exercise test. Participants were divided into CRF categories of low, moderate, and high fit by age group and by TG:HDL-C quartiles. Hazard ratios for CHD mortality were computed using Cox regression analysis.A total of 556 deaths due to CHD occurred during a mean ± SD of 16.6±9.7 years (669,678 man-years) of follow-up. A significant positive trend in adjusted CHD mortality was shown across decreasing CRF categories (P for trend<.01). Adjusted hazard ratios were significantly higher across increasing TG:HDL-C quartiles as well (P for trend<.01). When grouped by CRF category and TG:HDL-C quartile, there was a significant positive trend (P=.04) in CHD mortality across decreasing CRF categories in each TG:HDL-C quartile.Both CRF and TG:HDL-C are significantly associated with CHD mortality in men. The risk of CHD mortality in each TG:HDL-C quartile was significantly attenuated in men with moderate to high CRF compared with men with low CRF. These results suggest that assessment of CRF and TG:HDL-C should be included for routine CHD mortality risk assessment and risk management.
View details for DOI 10.1016/j.mayocp.2017.08.015
View details for PubMedID 29157534
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Moderate to High Levels of Cardiorespiratory Fitness Attenuate the Effects of Triglyceride to High-Density Lipoprotein Cholesterol Ratio on Coronary Heart Disease Mortality in Men
MAYO CLINIC PROCEEDINGS
2017; 92 (12): 1763–71
View details for DOI 10.1016/j.mayocp.2017.08.015
View details for Web of Science ID 000416752300007
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Relationship between simple markers of insulin resistance and coronary artery calcification
JOURNAL OF CLINICAL LIPIDOLOGY
2017; 11 (4): 1007–12
Abstract
Insulin resistance in apparently healthy persons is associated with a cluster of metabolic abnormalities that promote coronary atherosclerosis. Identifying these individuals before manifest disease would provide useful clinical information.We hypothesized that combining 2 simple markers of insulin resistance, prediabetes (PreDM) and triglyceride (TG) concentration ≥150 mg/dL, would identify apparently healthy persons with adverse cardiometabolic risk profiles and increased coronary artery calcium (CAC) compared with those with neither or only 1 abnormality.A cross-sectional analysis was performed using data from 25,886 apparently healthy individuals (18,453 men and 7433 women) evaluated at the Cooper Clinic from 1998 to 2015. Participants were divided into those with a normal fasting glucose concentrations (<100 mg/dL = normal fasting glucose) or PreDM (fasting plasma glucose ≥100 and <126 mg/dL) and further subdivided into those with a plasma TG concentration <150 or ≥150 mg/dL. These 4 groups were compared on the basis of multiple coronary artery disease risk factors and the presence of CAC determined during their evaluation.Participants with PreDM and a TG concentration ≥150 mg/dL had a significantly more adverse coronary artery disease risk profile than individuals with either abnormality or only 1 abnormality (PreDM or TG concentration ≥150 mg/dL). Furthermore, the odds of detectable CAC were higher in participants with PreDM and a TG ≥ 150 mg/dL than in participants with neither or only 1 abnormality.The presence of 2 markers of insulin resistance, PreDM and TG concentration ≥150 mg/dL, is associated with increased cardiometabolic risk and detectable CAC within a population of apparently healthy individuals.
View details for PubMedID 28652190
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Activity Recognition in Youth Using Single Accelerometer Placed at Wrist or Ankle
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2017; 49 (4): 801-812
Abstract
State-of-the-art methods for recognizing human activity using raw data from body worn accelerometers have primarily been validated with data collected from adults. This study applies a previously available method for activity classification using wrist or ankle accelerometer to work on datasets collected from both adults and youth.An algorithm for detecting activity from wrist-worn accelerometers, originally developed using data from 33 adults, is tested on a dataset of 20 youth (age 13±1.3). The algorithm is also extended by adding new features required to improve performance on the youth dataset. Subsequent tests on both the adult and youth data were performed using crossed tests (training on one group and testing on the other) and leave-one-subject-out cross-validation.The new feature set improved overall recognition using wrist data by 2.3% for adults and 5.1% for youth. Leave-one-subject-out cross-validation accuracy performance was 87.0% (wrist) and 94.8% (ankle) for adults, and 91.0% (wrist) and 92.4% (ankle) for youth. Merging the two datasets, overall accuracy was 88.5% (wrist) and 91.6% (ankle).Previously available methodological approaches for activity classification in adults can be extended to youth data. Including youth data in the training phase and using features designed to capture information on the peculiar activity fragmentation of young participants allows a better fit of the methodological framework to the characteristics of activity in youth, improving its overall performance. The proposed algorithm differentiates ambulation from sedentary activities that involve gesturing in wrist data, such as that being collected in large surveillance studies.
View details for DOI 10.1249/MSS.0000000000001144
View details for Web of Science ID 000397910300022
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Feasibility of Obtaining Measures of Lifestyle From a Smartphone App: The MyHeart Counts Cardiovascular Health Study.
JAMA cardiology
2017; 2 (1): 67-76
Abstract
Studies have established the importance of physical activity and fitness, yet limited data exist on the associations between objective, real-world physical activity patterns, fitness, sleep, and cardiovascular health.To assess the feasibility of obtaining measures of physical activity, fitness, and sleep from smartphones and to gain insights into activity patterns associated with life satisfaction and self-reported disease.The MyHeart Counts smartphone app was made available in March 2015, and prospective participants downloaded the free app between March and October 2015. In this smartphone-based study of cardiovascular health, participants recorded physical activity, filled out health questionnaires, and completed a 6-minute walk test. The app was available to download within the United States.The feasibility of consent and data collection entirely on a smartphone, the use of machine learning to cluster participants, and the associations between activity patterns, life satisfaction, and self-reported disease.From the launch to the time of the data freeze for this study (March to October 2015), the number of individuals (self-selected) who consented to participate was 48 968, representing all 50 states and the District of Columbia. Their median age was 36 years (interquartile range, 27-50 years), and 82.2% (30 338 male, 6556 female, 10 other, and 3115 unknown) were male. In total, 40 017 (81.7% of those who consented) uploaded data. Among those who consented, 20 345 individuals (41.5%) completed 4 of the 7 days of motion data collection, and 4552 individuals (9.3%) completed all 7 days. Among those who consented, 40 017 (81.7%) filled out some portion of the questionnaires, and 4990 (10.2%) completed the 6-minute walk test, made available only at the end of 7 days. The Heart Age Questionnaire, also available after 7 days, required entering lipid values and age 40 to 79 years (among 17 245 individuals, 43.1% of participants). Consequently, 1334 (2.7%) of those who consented completed all fields needed to compute heart age and a 10-year risk score. Physical activity was detected for a mean (SD) of 14.5% (8.0%) of individuals' total recorded time. Physical activity patterns were identified by cluster analysis. A pattern of lower overall activity but more frequent transitions between active and inactive states was associated with equivalent self-reported cardiovascular disease as a pattern of higher overall activity with fewer transitions. Individuals' perception of their activity and risk bore little relation to sensor-estimated activity or calculated cardiovascular risk.A smartphone-based study of cardiovascular health is feasible, and improvements in participant diversity and engagement will maximize yield from consented participants. Large-scale, real-world assessment of physical activity, fitness, and sleep using mobile devices may be a useful addition to future population health studies.
View details for DOI 10.1001/jamacardio.2016.4395
View details for PubMedID 27973671
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Dietary Patterns and Long-Term Survival: a Retrospective Study of Healthy Primary Care Patients.
The American journal of medicine
2017
Abstract
Dietary patterns are related to mortality in selected populations with comorbidities. We studied whether dietary patterns are associated with long-term survival in a middle-aged, healthy population.In this observational cohort study at the Cooper Clinic preventive medicine center (Dallas, Texas), a volunteer sample of 11,376 men and women with no history of myocardial infarction or stroke completed a baseline dietary assessment between 1987-1999 and were observed for an average of 18 years. Proportional hazard regressions, including a tree-augmented model, were used to assess the association of the Dietary Approaches to Stop Hypertension (DASH) dietary pattern, Mediterranean dietary pattern, and individual dietary components with mortality. The primary outcome was death from all causes. The secondary outcome was death from cardiovascular disease.Mean baseline age was 47 years. Each quintile increase in the DASH diet score was associated with a 6% lower adjusted risk for all-cause mortality (P<0.02). The Mediterranean diet was not independently associated with all-cause or cardiovascular mortality. Solid fats and added sugars were the most predictive of mortality. Individuals who consumed >34% of their daily calories as solid fats had the highest risk for all-cause mortality.The DASH dietary pattern was associated with significantly lower all-cause mortality over nearly two decades of follow-up in a middle-aged, generally healthy population. Added solid fat and added sugar intake were the most predictive of all-cause mortality. These results suggest that promotion of a healthy dietary pattern should begin in middle age, before the development of comorbid risk factors.
View details for PubMedID 28860032
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Activity Recognition in Youth Using Single Accelerometer Placed at Wrist or Ankle.
Medicine and science in sports and exercise
2016: -?
Abstract
State-of-the-art methods for recognizing human activity using raw data from body worn accelerometers have primarily been validated with data collected from adults. This study applies a previously available method for activity classification using wrist or ankle accelerometer to work on datasets collected from both adults and youth.An algorithm for detecting activity from wrist-worn accelerometers, originally developed using data from 33 adults, is tested on a dataset of 20 youth (age 13±1.3). The algorithm is also extended by adding new features required to improve performance on the youth dataset. Subsequent tests on both the adult and youth data were performed using crossed tests (training on one group and testing on the other) and leave-one-subject-out cross-validation.The new feature set improved overall recognition using wrist data by 2.3% for adults and 5.1% for youth. Leave-one-subject-out cross-validation accuracy performance was 87.0% (wrist) and 94.8% (ankle) for adults, and 91.0% (wrist) and 92.4% (ankle) for youth. Merging the two datasets, overall accuracy was 88.5% (wrist) and 91.6% (ankle).Previously available methodological approaches for activity classification in adults can be extended to youth data. Including youth data in the training phase and using features designed to capture information on the peculiar activity fragmentation of young participants allows a better fit of the methodological framework to the characteristics of activity in youth, improving its overall performance. The proposed algorithm differentiates ambulation from sedentary activities that involve gesturing in wrist data, such as that being collected in large surveillance studies.
View details for PubMedID 27820724
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Is Cardiorespiratory Fitness Still as Relevant for Mortality Risk in the Statin Era?: 1988 Board #140 June 2, 3: 30 PM - 5: 00 PM.
Medicine and science in sports and exercise
2016; 48 (5): 553-?
View details for DOI 10.1249/01.mss.0000486661.12762.86
View details for PubMedID 27360813
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Twenty-four Hours of Sleep, Sedentary Behavior, and Physical Activity with Nine Wearable Devices.
Medicine and science in sports and exercise
2016; 48 (3): 457-465
Abstract
Getting enough sleep, exercising, and limiting sedentary activities can greatly contribute to disease prevention and overall health and longevity. Measuring the full 24-h activity cycle-sleep, sedentary behavior (SED), light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA)-may now be feasible using small wearable devices.This study compared nine devices for accuracy in a 24-h activity measurement.Adults (n = 40, 47% male) wore nine devices for 24 h: ActiGraph GT3X+, activPAL, Fitbit One, GENEactiv, Jawbone Up, LUMOback, Nike Fuelband, Omron pedometer, and Z-Machine. Comparisons (with standards) were made for total sleep time (Z-machine), time spent in SED (activPAL), LPA (GT3X+), MVPA (GT3X+), and steps (Omron). Analysis included mean absolute percent error, equivalence testing, and Bland-Altman plots.Error rates ranged from 8.1% to 16.9% for sleep, 9.5% to 65.8% for SED, 19.7% to 28.0% for LPA, 51.8% to 92% for MVPA, and 14.1% to 29.9% for steps. Equivalence testing indicated that only two comparisons were significantly equivalent to standards: the LUMOback for SED and the GT3X+ for sleep. Bland-Altman plots indicated GT3X+ had the closest measurement for sleep, LUMOback for SED, GENEactiv for LPA, Fitbit for MVPA, and GT3X+ for steps.Currently, no device accurately captures activity data across the entire 24-h day, but the future of activity measurement should aim for accurate 24-h measurement as a goal. Researchers should continue to select measurement devices on the basis of their primary outcomes of interest.
View details for DOI 10.1249/MSS.0000000000000778
View details for PubMedID 26484953
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Adherence to an Aerobic Exercise Intervention after an Implantable Cardioverter Defibrillator (ICD).
Pacing and clinical electrophysiology : PACE
2016; 39 (2): 128-39
Abstract
Exercise adherence is an important element in achieving important exercise outcomes. The purpose of this study was to describe adherence in a home-based aerobic exercise program following an implantable cardioverter defibrillator (ICD), determine effects of adherence on peakVO2 , and outline reasons for nonadherence.A single-blind randomized control trial of home walking compared to usual care in 160 patients with an ICD for primary or secondary prevention was conducted. This report is on adherence in the exercise arm (N = 84). Home walking exercise consisted of 8 weeks of aerobic conditioning (60 minutes/day, 5 days/week) followed by 16 weeks of aerobic maintenance (150 minutes/week, 30 minutes/session) at 60-80% of heart rate reserve. Adherence was tracked using Polar heart rate (HR) monitors, pedometers, home exercise logs, and telephone follow-up. Adherence was defined as performing at least 80% of prescribed exercise. For aerobic conditioning, there was a mean frequency of 3.81 walks/week, duration of 1,873 minutes walked, and 17.5% of exercise was in the target HR (THR) zone. For aerobic maintenance, there was a mean frequency of 2.4 walks/week, duration of 1,872 minutes/walked, and 8.7% of exercise was in the THR zone. Those who were 80% adherent achieved a 3.4 mL/kg/min (P = 0.03) improvement in peakVO2 over those who were <80% adherent. Reasons for nonadherence to exercise ranged from scheduling issues to viral illness and fatigue.Adherence to aerobic exercise frequency and duration was high with few dropouts, resulting in higher peakVO2 . Exercise monitoring equipment encouraged adherence and conferred a sense of safety to exercise.
View details for DOI 10.1111/pace.12782
View details for PubMedID 26548341
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Effects of Varying Epoch Lengths, Wear Time Algorithms, and Activity Cut-Points on Estimates of Child Sedentary Behavior and Physical Activity from Accelerometer Data.
PloS one
2016; 11 (3)
Abstract
To examine the effects of accelerometer epoch lengths, wear time (WT) algorithms, and activity cut-points on estimates of WT, sedentary behavior (SB), and physical activity (PA).268 7-11 year-olds with BMI ≥ 85th percentile for age and sex wore accelerometers on their right hips for 4-7 days. Data were processed and analyzed at epoch lengths of 1-, 5-, 10-, 15-, 30-, and 60-seconds. For each epoch length, WT minutes/day was determined using three common WT algorithms, and minutes/day and percent time spent in SB, light (LPA), moderate (MPA), and vigorous (VPA) PA were determined using five common activity cut-points. ANOVA tested differences in WT, SB, LPA, MPA, VPA, and MVPA when using the different epoch lengths, WT algorithms, and activity cut-points.WT minutes/day varied significantly by epoch length when using the NHANES WT algorithm (p < .0001), but did not vary significantly by epoch length when using the ≥ 20 minute consecutive zero or Choi WT algorithms. Minutes/day and percent time spent in SB, LPA, MPA, VPA, and MVPA varied significantly by epoch length for all sets of activity cut-points tested with all three WT algorithms (all p < .0001). Across all epoch lengths, minutes/day and percent time spent in SB, LPA, MPA, VPA, and MVPA also varied significantly across all sets of activity cut-points with all three WT algorithms (all p < .0001).The common practice of converting WT algorithms and activity cut-point definitions to match different epoch lengths may introduce significant errors. Estimates of SB and PA from studies that process and analyze data using different epoch lengths, WT algorithms, and/or activity cut-points are not comparable, potentially leading to very different results, interpretations, and conclusions, misleading research and public policy.
View details for DOI 10.1371/journal.pone.0150534
View details for PubMedID 26938240
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New insights into discrepancies between self-reported and accelerometer-measured moderate to vigorous physical activity among women - the mPED trial.
BMC public health
2016; 16 (1): 761-?
Abstract
The aims of this report were 1) to describe the duration of moderate to vigorous physical activity (MVPA) and the proportion of participants meeting the recommended criterion of at least 150 min of MVPA per week as measured by the 7 Day Physical Activity Recall Questionnaire (7D-PAR) and accelerometer among women who were enrolled in the mPED trial; 2) to assess the level of agreement of the two measures using a Bland-Altman plot; and 3) to describe the positive and negative predictive values (PPV and NPV, respectively) of meeting the guidelines by calculating the percentage of women meeting the physical activity recommendation by the 7D-PAR who also met this recommendation based on data from the accelerometer.Baseline data on duration of MVPA from the mPED trial were analyzed for 215 women. Among the women who met the recommended criterion by the 7D-PAR (self-report), we calculated the proportion of individuals who also met it by the accelerometer (objective measure). A Bland Altman Plot was used to assess concordance between the two measures.The mean age was 52.4 (±11.2) years; 54.4 % were white; and 48.8 % were single or divorced. While median MVPA was 160 min/week by the 7D-PAR, it was only 24 min/week in the accelerometer. A total of 117 women met the 150-min criterion by the 7D-PAR. Of these, only 18 also met the criterion by the objective measure (PPV 15.4 %, 95 % CI 9.4-23.2 %). Among the 98 women who did not meet the criterion by the 7D-PAR, none met it by the accelerometer (NPV 100 %). A Bland Altman plot showed the mean difference of +145 min between the two measures with a 95 % limit of agreement at + 471 to -181 min.The large discrepancy between the self-reported and objective measures of MVPA meeting the 150-min criterion suggests that self-reported physical activity measures should be used with caution in intervention studies. While our data suggest that self-report could be used to identify a physically inactive sample, it would be likely to over-estimate the proportions of women who become active in one or both arms of trials of interventions promoting MVPA.ClinicalTrials.gov NCT01280812.
View details for DOI 10.1186/s12889-016-3348-7
View details for PubMedID 27514368
View details for PubMedCentralID PMC4982411
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Is There a Gradient of Mortality Risk among Men with Low Cardiorespiratory Fitness?
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2015; 47 (9): 1825-1832
Abstract
A low level of cardiorespiratory fitness (CRF) is a strong and independent predictor of all-cause mortality in men; however, it is unknown whether a gradient of mortality risk exists within the lowest CRF category.A total of 6251 apparently healthy men (mean age, 48.7 ± 6.3 yr) completed a comprehensive baseline clinical examination, including a maximal treadmill exercise test at Cooper Clinic between 1971 and 2006. In accord with previous studies using this cohort, low CRF was defined as a treadmill time in the first quintile within each age category of 40-49, 50-59, and 60-69 yr. The low CRF cohort was then grouped by tertiles (low/low, LL; mid/low, ML; and high/low, HL) using the same age categories.After a mean follow-up period of 19.1 ± 10.4 yr, 1259 deaths occurred. Adjusted all-cause mortality rates were 57.0, 31.1, and 34.4 deaths per 10,000 man-years across LL, ML, and HL CRF categories for the 40- to 49-yr-old age group (P trend = 0.007). Similar trends were seen across low CRF categories for the 50- to 59-yr-old and 60- to 69-yr-old age groups (P trend = 0.02 and 0.09, respectively). When using treadmill time as a continuous variable, each 1-min increment in treadmill time was associated with a 9%, 11%, and 15% reduction in risk of all-cause mortality among low-CRF men in the 40-49, 50-59, and 60-69 age groups, respectively.An inverse trend in all-cause mortality exists among men across LL, ML, and HL CRF groups. Although all low-fit men should be targeted for physical activity intervention, it is especially important to target the LL CRF group.
View details for DOI 10.1249/MSS.0000000000000608
View details for Web of Science ID 000359527500008
View details for PubMedID 25551401
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Physical Activity Versus Cardiorespiratory Fitness: Two (Partly) Distinct Components of Cardiovascular Health?
PROGRESS IN CARDIOVASCULAR DISEASES
2015; 57 (4): 324-329
Abstract
Physical activity (PA) and cardiorespiratory fitness (CRF) both have inverse relationships to cardiovascular (CV) morbidity and mortality. Recent position papers and guidelines have identified the important role of both of these factors in CV health. The benefits of PA and CRF in the prevention of CV disease and risk factors are reviewed. In addition, assessment methodology and utilization in the research and clinical arenas are discussed. Finally, the benefits, methodology, and utilization are compared and contrasted to better understand the two (partly) distinct components and their impact on CV health.
View details for DOI 10.1016/j.pcad.2014.09.008
View details for Web of Science ID 000348003900006
View details for PubMedID 25269066
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Identifying Factors Associated With Dropout During Prerandomization Run-in Period From an mHealth Physical Activity Education Study: The mPED Trial.
JMIR mHealth and uHealth
2015; 3 (2)
Abstract
The mobile phone-based physical activity education (mPED) trial is a randomized controlled trial (RCT) evaluating a mobile phone-delivered physical activity intervention for women. The study includes a run-in period to maximize the internal validity of the intervention trial, but little is known about factors related to successful run-in completion, and thus about potential threats to external validity.Objectives of this study are (1) to determine the timing of dropout during the run-in period, reasons for dropout, optimum run-in duration, and relevant run-in components, and (2) to identify predictors of failure to complete the run-in period.A total of 318 physically inactive women met preliminary eligibility criteria and were enrolled in the study between May 2011 and April 2014. A 3-week run-in period was required prior to randomization and included using a mobile phone app and wearing a pedometer. Cross-sectional analysis identified predictors of dropout.Out of 318 participants, 108 (34.0%) dropped out prior to randomization, with poor adherence using the study equipment being the most common reason. Median failure time was 17 days into the run-in period. In univariate analyses, nonrandomized participants were younger, had lower income, were less likely to drive regularly, were less likely to have used a pedometer prior to the study, were generally less healthy, had less self-efficacy for physical activity, and reported more depressive symptoms than randomized participants. In multivariate competing risks models, not driving regularly in the past month and not having used a pedometer prior to the study were significantly associated with failure to be randomized (P=.04 and .006, respectively), controlling for age, race/ethnicity, education, shift work, and use of a study-provided mobile phone.Regular driving and past pedometer use were associated with reduced dropout during the prerandomization run-in period. Understanding these characteristics is important for identifying higher-risk participants, and implementing additional help strategies may be useful for reducing dropout.ClinicalTrials.gov NCT01280812; https://clinicaltrials.gov/ct2/show/NCT01280812 (Archived by WebCite at http://www.webcitation.org/6XFC5wvrP).
View details for DOI 10.2196/mhealth.3928
View details for PubMedID 25872754
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The Stanford Leisure-Time Activity Categorical Item (L-Cat): a single categorical item sensitive to physical activity changes in overweight/obese women
INTERNATIONAL JOURNAL OF OBESITY
2013; 37 (12): 1597-1602
Abstract
Background:Physical activity is essential for chronic disease prevention, yet <40% of overweight/obese adults meet the national activity recommendations. For time-efficient counseling, clinicians need a brief, easy-to-use tool that reliably and validly assesses a full range of activity levels, and, most importantly, is sensitive to clinically meaningful changes in activity. The Stanford Leisure-Time Activity Categorical Item (L-Cat) is a single item comprising six descriptive categories ranging from inactive to very active. This novel methodological approach assesses national activity recommendations as well as multiple clinically relevant categories below and above the recommendations, and incorporates critical methodological principles that enhance psychometrics (reliability, validity and sensitivity to change).Methods:We evaluated the L-Cat's psychometrics among 267 overweight/obese women who were asked to meet the national activity recommendations in a randomized behavioral weight-loss trial.Results:The L-Cat had excellent test-retest reliability (κ=0.64, P<0.001) and adequate concurrent criterion validity; each L-Cat category at 6 months was associated with 1059 more daily pedometer steps (95% CI 712-1407, β=0.38, P<0.001) and 1.9% greater initial weight loss at 6 months (95% CI -2.4 to -1.3, β=-0.38, P<0.001). Of interest, L-Cat categories differentiated from each other in a dose-response gradient for steps and weight loss (Ps<0.05) with excellent face validity. The L-Cat was sensitive to change in response to the trial's activity component. Women increased one L-Cat category at 6 months (M=1.0±1.4, P<0.001); 55.8% met the recommendations at 6 months whereas 20.6% did at baseline (P<0.001). Even among women not meeting the recommendations at both baseline and 6 months (n=106), women who moved 1 L-Cat categories at 6 months lost more weight than those who did not (M=-4.6%, 95% CI -6.7 to -2.5, P<0.001).Conclusions:Given strong psychometrics, the L-Cat has timely potential for clinical use such as tracking activity changes via electronic medical records, especially among overweight/obese populations who are unable or unlikely to reach national recommendations.International Journal of Obesity advance online publication, 16 April 2013; doi:10.1038/ijo.2013.36.
View details for DOI 10.1038/ijo.2013.36
View details for Web of Science ID 000328456200013
View details for PubMedID 23588625
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Cardiorespiratory Fitness, Body Mass Index, and Heart Failure Mortality in Men Cooper Center Longitudinal Study
CIRCULATION-HEART FAILURE
2013; 6 (5): 898-905
Abstract
We evaluated the individual and joint associations among cardiorespiratory fitness (CRF), body mass index, and heart failure (HF) mortality, as well as the additive effect of an increasing number of cardiovascular risk factors on HF mortality in fit versus unfit men.A total of 44 674 men without a history of cardiovascular disease underwent a baseline examination between 1971 and 2010. Measures included body mass index and CRF quantified as duration of maximal treadmill exercise testing. Participants were divided into age-specific low, moderate, and high CRF categories. Hazard ratios were computed with Cox regression analysis. During a mean follow-up of 19.8±10.4 years, 153 HF deaths occurred. Adjusted hazard ratios across high, moderate, and low CRF categories were 1.0, 1.63, and 3.97, respectively, whereas those of normal, overweight, and obese body mass index categories were 1.0, 1.56, and 3.71, respectively (P for trend <0.0001 for each). When grouped into categories of fit and unfit (upper 80% and lower 20% of CRF distribution, respectively), hazard ratios were significantly lower in fit compared with unfit men in normal and overweight body mass index strata (P<0.002) but not in obese men. Within men matched for the same number of HF risk factors, fit men had significantly lower HF mortality than unfit men (P≤0.02).Higher baseline CRF is associated with lower HF mortality risk in men, regardless of the number of HF risk factors present. Men should be counseled on physical activity with the goal of achieving at least a moderate level of CRF, thereby presumably decreasing their risk of HF mortality.
View details for DOI 10.1161/CIRCHEARTFAILURE.112.000088
View details for Web of Science ID 000335234500007
View details for PubMedID 23873472
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Estimating Activity and Sedentary Behavior from an Accelerometer on the Hip or Wrist
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2013; 45 (5): 964-975
Abstract
Previously, the National Health and Examination Survey measured physical activity with an accelerometer worn on the hip for 7 d but recently changed the location of the monitor to the wrist. This study compared estimates of physical activity intensity and type with an accelerometer on the hip versus the wrist.Healthy adults (n = 37) wore triaxial accelerometers (Wockets) on the hip and dominant wrist along with a portable metabolic unit to measure energy expenditure during 20 activities. Motion summary counts were created, and receiver operating characteristic (ROC) curves were then used to determine sedentary and activity intensity thresholds. Ambulatory activities were separated from other activities using the coefficient of variation of the counts. Mixed-model predictions were used to estimate activity intensity.The ROC for determining sedentary behavior had greater sensitivity and specificity (71% and 96%) at the hip than at the wrist (53% and 76%), as did the ROC for moderate- to vigorous-intensity physical activity on the hip (70% and 83%) versus the wrist (30% and 69%). The ROC for the coefficient of variation associated with ambulation had a larger AUC at the hip compared to the wrist (0.83 and 0.74). The prediction model for activity energy expenditure resulted in an average difference of 0.55 ± 0.55 METs on the hip and 0.82 ± 0.93 METs on the wrist.Methods frequently used for estimating activity energy expenditure and identifying activity intensity thresholds from an accelerometer on the hip generally do better than similar data from an accelerometer on the wrist. Accurately identifying sedentary behavior from a lack of wrist motion presents significant challenges.
View details for DOI 10.1249/MSS.0b013e31827f0d9c
View details for Web of Science ID 000317847000021
View details for PubMedID 23247702
View details for PubMedCentralID PMC3631449
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The Association Between Midlife Cardiorespiratory Fitness Levels and Later-Life Dementia
ANNALS OF INTERNAL MEDICINE
2013; 158 (3): 162-?
View details for Web of Science ID 000314757900003
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Physical Activity and Physical Fitness Standardizing Assessment with the PhenX Toolkit
AMERICAN JOURNAL OF PREVENTIVE MEDICINE
2012; 42 (5): 486-492
Abstract
The focus of the PhenX (Phenotypes and eXposures) Toolkit is to provide researchers whose expertise lies outside a particular area with key measures identified by experts for uniform use in large-scale genetic studies and other extensive epidemiologic efforts going forward. The current paper specifically addresses the PhenX Toolkit research domain of physical activity and physical fitness (PA/PF), which are often associated with health outcomes. A Working Group (WG) of content experts completed a 6-month consensus process in which they identified a set of 14 high-priority, low-burden, and scientifically supported measures. During this process, the WG considered self-reported and objective measures that included the latest technology (e.g., accelerometers, pedometers, and heart-rate monitors). They also sought the input of measurement experts and other members of the research community during their deliberations. A majority of the measures include protocols for children (or adolescents), adults, and older adults or are applicable to all ages. Measures from the PA/PF domain and 20 other domains are publicly available and found at the PhenX Toolkit website, www.phenxtoolkit.org. The use of common measures and protocols across large studies enhances the capacity to combine or compare data across studies, benefiting both PA/PF experts and non-experts. Use of these common measures by the research community should increase statistical power and enhance the ability to answer scientific questions that previously might have gone unanswered.
View details for DOI 10.1016/j.amepre.2011.11.017
View details for Web of Science ID 000302963300014
View details for PubMedID 22516489
View details for PubMedCentralID PMC3331998
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Cardiorespiratory Fitness and Metabolic Risk
AMERICAN JOURNAL OF CARDIOLOGY
2012; 109 (7): 988-993
Abstract
The present study sought to evaluate the relation between cardiovascular risk factors and cardiorespiratory fitness (CRF) in a large population. Low CRF has been associated with increased total mortality and cardiovascular mortality. The mechanisms underlying greater cardiovascular mortality have not yet been determined. A series of cardiovascular risk factors were measured in 59,820 men and 22,192 women who had undergone determinations of CRF with maximal exercise testing. The risk factor profiles were segregated into 5 quintiles of CRF. With decreasing CRF, increases occurred in obesity, triglycerides, non-high-density lipoprotein cholesterol, triglyceride/high-density lipoprotein ratios, blood pressure, metabolic syndrome, diabetes, and cigarette smoking. Self-reported physical activity declined with decreasing levels of CRF. In conclusion, it appears likely that the enrichment of cardiovascular risk factors, especially metabolic risk factors, account for a portion of the increased cardiovascular mortality in low-fitness subjects. The mechanisms responsible for this enrichment in subjects with a low CRF represent a challenge for future research.
View details for DOI 10.1016/j.amjcard.2011.11.031
View details for Web of Science ID 000302111400010
View details for PubMedID 22221951
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Reliability and Validity of CHAMPS Self-Reported Sedentary-to-Vigorous Intensity Physical Activity in Older Adults
JOURNAL OF PHYSICAL ACTIVITY & HEALTH
2012; 9 (2): 225-236
Abstract
Recent research highlights the potential value of differentiating between categories of physical activity intensities as predictors of health and well-being. This study sought to assess reliability and concurrent validity of sedentary (ie, 1 METs), low-light (ie, >1 and ≤2 METs; eg, playing cards), high-light (ie, >2 and <3 METs; eg, light walking), moderate-to-vigorous physical activity (MVPA, ≥3 METs), and "total activity" (≥2 METs) from the CHAMPS survey. Further, this study explored over-reporting and double-reporting.CHAMPS data were gathered from the Seniors Neighborhood Quality of Life Study, an observational study of adults aged 65+ years conducted in 2 US regions.Participants (N = 870) were 75.3 ± 6.8 years old, with 56% women and 71% white. The CHAMPS sedentary, low-light, high-light, total activity, and MVPA variables had acceptable test-retest reliability (ICCs 0.56-0.70). The CHAMPS high-light (ρ = 0.27), total activity (ρ = 0.34), and MVPA (ρ = 0.37) duration scales were moderately associated with accelerometry minutes of corresponding intensity, and the sedentary scale (ρ = 0.12) had a lower, but significant correlation. Results suggested that several CHAMPS items may be susceptible to over-reporting (eg, walking, housework).CHAMPS items effectively measured high-light, total activity, and MVPA in seniors, but further refinement is needed for sedentary and low-light activity.
View details for Web of Science ID 000300960800008
View details for PubMedID 22368222
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Physical Activity by Self-Report: A Brief History and Future Issues
JOURNAL OF PHYSICAL ACTIVITY & HEALTH
2012; 9: S5-S10
Abstract
For the scientific domain of physical activity and public health research to advance its agenda of health promotion and disease prevention continued development of measurement methodologies is essential. Over the past 50 years most data supporting a favorable relationship between habitual physical activity and chronic disease morbidity and mortality have been obtained using self-report methods, including questionnaires, logs, recalls, and diaries. Many of these instruments have been shown to have reasonable validity and reliability for determining general type, amount, intensity, and bout duration, but typically do better for groups than individuals with some instruments lacking the sensitivity to detect change in activity. During the past decade the objective assessment of physical activity using accelerometer-based devices has demonstrated substantial potential, especially in documenting the pattern of light-, moderate-, and vigorous-intensity activity throughout the day. However, these devices do not provide information on activity type, location or context. Research that combines the strengths of both self-report and objective measures has the potential to provide new insights into the benefits of physical activity and how to implement successful interventions.
View details for Web of Science ID 000299764400002
View details for PubMedID 22287448
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Assessment of Physical Activity Using Wearable Monitors: Recommendations for Monitor Calibration and Use in the Field
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2012; 44: S1-S4
Abstract
This article provides recommendations for the use of wearable monitors for assessing physical activity. We have provided recommendations for measurement researchers, end users, and developers of activity monitors. We discuss new horizons and future directions in the field of objective measurement of physical activity and present challenges that remain for the future. These recommendations are based on the proceedings from the workshop "Objective Measurement of Physical Activity: Best Practices and Future Direction," held on July 20-21, 2009, and also on data and information presented since the workshop.
View details for DOI 10.1249/MSS.0b013e3182399b7e
View details for Web of Science ID 000298732000001
View details for PubMedID 22157769
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The mPED randomized controlled clinical trial: applying mobile persuasive technologies to increase physical activity in sedentary women protocol
BMC PUBLIC HEALTH
2011; 11
Abstract
Despite the significant health benefits of regular physical activity, approximately half of American adults, particularly women and minorities, do not meet the current physical activity recommendations. Mobile phone technologies are readily available, easily accessible and may provide a potentially powerful tool for delivering physical activity interventions. However, we need to understand how to effectively apply these mobile technologies to increase and maintain physical activity in physically inactive women. The purpose of this paper is to describe the study design and protocol of the mPED (mobile phone based physical activity education) randomized controlled clinical trial that examines the efficacy of a 3-month mobile phone and pedometer based physical activity intervention and compares two different 6-month maintenance interventions.A randomized controlled trial (RCT) with three arms; 1) PLUS (3-month mobile phone and pedometer based physical activity intervention and 6-month mobile phone diary maintenance intervention), 2) REGULAR (3-month mobile phone and pedometer based physical activity intervention and 6-month pedometer maintenance intervention), and 3) CONTROL (pedometer only, but no intervention will be conducted). A total of 192 physically inactive women who meet all inclusion criteria and successfully complete a 3-week run-in will be randomized into one of the three groups. The mobile phone serves as a means of delivering the physical activity intervention, setting individualized weekly physical activity goals, and providing self-monitoring (activity diary), immediate feedback and social support. The mobile phone also functions as a tool for communication and real-time data capture. The primary outcome is objectively measured physical activity.If efficacy of the intervention with a mobile phone is demonstrated, the results of this RCT will be able to provide new insights for current behavioral sciences and mHealth.ClinicalTrials.gov#:NCTO1280812.
View details for DOI 10.1186/1471-2458-11-933
View details for Web of Science ID 000301497500001
View details for PubMedID 22168267
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Dose Response Between Physical Activity and Risk of Coronary Heart Disease A Meta-Analysis
CIRCULATION
2011; 124 (7): 789-U84
Abstract
No reviews have quantified the specific amounts of physical activity required for lower risks of coronary heart disease when assessing the dose-response relation. Instead, previous reviews have used qualitative estimates such as low, moderate, and high physical activity.We performed an aggregate data meta-analysis of epidemiological studies investigating physical activity and primary prevention of CHD. We included prospective cohort studies published in English since 1995. After reviewing 3194 abstracts, we included 33 studies. We used random-effects generalized least squares spline models for trend estimation to derive pooled dose-response estimates. Among the 33 studies, 9 allowed quantitative estimates of leisure-time physical activity. Individuals who engaged in the equivalent of 150 min/wk of moderate-intensity leisure-time physical activity (minimum amount, 2008 U.S. federal guidelines) had a 14% lower coronary heart disease risk (relative risk, 0.86; 95% confidence interval, 0.77 to 0.96) compared with those reporting no leisure-time physical activity. Those engaging in the equivalent of 300 min/wk of moderate-intensity leisure-time physical activity (2008 U.S. federal guidelines for additional benefits) had a 20% (relative risk, 0.80; 95% confidence interval, 0.74 to 0.88) lower risk. At higher levels of physical activity, relative risks were modestly lower. People who were physically active at levels lower than the minimum recommended amount also had significantly lower risk of coronary heart disease. There was a significant interaction by sex (P=0.03); the association was stronger among women than men.These findings provide quantitative data supporting US physical activity guidelines that stipulate that "some physical activity is better than none" and "additional benefits occur with more physical activity."
View details for DOI 10.1161/CIRCULATIONAHA.110.010710
View details for Web of Science ID 000293884900014
View details for PubMedID 21810663
View details for PubMedCentralID PMC3158733
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2011 Compendium of Physical Activities: A Second Update of Codes and MET Values
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2011; 43 (8): 1575-1581
Abstract
The Compendium of Physical Activities was developed to enhance the comparability of results across studies using self-report physical activity (PA) and is used to quantify the energy cost of a wide variety of PA. We provide the second update of the Compendium, called the 2011 Compendium.The 2011 Compendium retains the previous coding scheme to identify the major category headings and specific PA by their rate of energy expenditure in MET. Modifications in the 2011 Compendium include cataloging measured MET values and their source references, when available; addition of new codes and specific activities; an update of the Compendium tracking guide that links information in the 1993, 2000, and 2011 compendia versions; and the creation of a Web site to facilitate easy access and downloading of Compendium documents. Measured MET values were obtained from a systematic search of databases using defined key words.The 2011 Compendium contains 821 codes for specific activities. Two hundred seventeen new codes were added, 68% (561/821) of which have measured MET values. Approximately half (317/604) of the codes from the 2000 Compendium were modified to improve the definitions and/or to consolidate specific activities and to update estimated MET values where measured values did not exist. Updated MET values accounted for 73% of all code changes.The Compendium is used globally to quantify the energy cost of PA in adults for surveillance activities, research studies, and, in clinical settings, to write PA recommendations and to assess energy expenditure in individuals. The 2011 Compendium is an update of a system for quantifying the energy cost of adult human PA and is a living document that is moving in the direction of being 100% evidence based.
View details for DOI 10.1249/MSS.0b013e31821ece12
View details for Web of Science ID 000292773000025
View details for PubMedID 21681120
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Impact of Body Mass Index, Physical Activity, and Other Clinical Factors on Cardiorespiratory Fitness (from the Cooper Center Longitudinal Study)
AMERICAN JOURNAL OF CARDIOLOGY
2011; 108 (1): 34-39
Abstract
Cardiorespiratory fitness (CRF) is widely accepted as an important reversible cardiovascular risk factor. In the present study, we examined the nonmodifiable and modifiable determinants of CRF within a large healthy Caucasian population of men and women. The study included 20,239 patients presenting to Cooper Clinic (Dallas, Texas) for a comprehensive medical examination from 2000 through 2010. CRF was determined by maximal treadmill exercise testing. Physical activity categories were 0 metabolic equivalent tasks (METs)/min/week (no self-reported moderate or vigorous intensity physical activity), 1 to 449 METs/min/week (not meeting physical activity guideline), 450 to 749 METs/min/week (meeting guideline), and ≥750 METs/min/week (exceeding guideline). Linear regression modeling was used to determine the most robust clinical factors associated with achieved treadmill time. Age, gender, body mass index (BMI), and physical activity were the most important factors associated with CRF, explaining 56% of the variance (R(2) = 0.56). The addition of all other factors combined (current smoking, systolic blood pressure, blood glucose, high-density and low-density lipoprotein cholesterol, health status) were associated with CRF (p <0.05) but additively only improved R(2) by 2%. There was a significant interaction between BMI and physical activity on CRF, such that normal-weight (BMI <25 kg/m(2)) subjects achieved higher CRF for a given level of physical activity compared to obese subjects (BMI ≥30 kg/m(2)). Percent body fat, not lean body mass, was the key factor driving this interaction. In conclusion, BMI was the most important clinical risk factor associated with CRF other than nonmodifiable risk factors age and gender. For a similar amount of physical activity, normal-weight subjects achieved a higher CRF level compared to obese subjects. These data suggest that obesity may offset the benefits of physical activity on achieved CRF, even in a healthy population of men and women.
View details for DOI 10.1016/j.amjcard.2011.02.338
View details for Web of Science ID 000292785600006
View details for PubMedID 21529738
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Physical Activity in Older Subjects Is Associated With Increased Coronary Vasodilation The ADVANCE Study
JACC-CARDIOVASCULAR IMAGING
2011; 4 (6): 622-629
Abstract
We investigated the association between physical activity and coronary vasodilation to nitroglycerin (NTG) in the ADVANCE (Atherosclerotic Disease, Vascular Function, and Genetic Epidemiology) cohort of older healthy subjects.Physical activity may exert its beneficial effects by augmenting coronary responsiveness to nitric oxide. The relationship between physical activity and coronary vasodilatory response to NTG, an exogenous nitric oxide donor, has not been studied in a community-based population with typical activity levels.In 212 older adults (ages 60 to 72 years) without cardiovascular disease, we measured the coronary vasodilatory response to NTG using magnetic resonance angiography and physical activity using the Stanford Seven-Day Physical Activity Recall Questionnaire. The primary predictor measure was total physical activity (kcal/kg/day). The primary outcome measure was coronary vasodilatory response (percent increase of cross-sectional area post-NTG).Coronary vasodilation was 27.6% in more active subjects (>35 kcal/kg/day, e.g., 1 h of walking per day) compared to 18.9% in less active subjects (p=0.03). Regression analysis showed a significant positive correlation between coronary vasodilation and physical activity (p=0.003), with a slope (beta) of 1.2% per kcal/kg/day. This finding remained significant after adjustment for cardiac risk factors, coronary calcium, the use of vasoactive or statin medications, and analysis of physical activity by quintiles (p < 0.05). Coronary vasodilation was also associated with physical activity intensity (p = 0.03).In an asymptomatic, community-based cohort of older adults, increased coronary vasodilatory response was independently associated with greater physical activity, supporting the benefits of exercise on the order of 1 h of walking per day.
View details for DOI 10.1016/j.jcmg.2011.05.001
View details for PubMedID 21679897
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Lifetime Risks for Cardiovascular Disease Mortality by Cardiorespiratory Fitness Levels Measured at Ages 45, 55, and 65 Years in Men The Cooper Center Longitudinal Study
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2011; 57 (15): 1604-1610
Abstract
The purpose of this study was to determine the association between fitness and lifetime risk for cardiovascular disease (CVD).Higher levels of traditional risk factors are associated with marked differences in lifetime risks for CVD. However, data are sparse regarding the association between fitness and the lifetime risk for CVD.We followed up 11,049 men who underwent clinical examination at the Cooper Institute in Dallas, Texas, before 1990 until the occurrence of CVD death, non-CVD death, or attainment of age 90 years (281,469 person-years of follow-up, median follow-up 25.3 years, 1,106 CVD deaths). Fitness was measured by the Balke protocol and categorized according to treadmill time into low, moderate, and high fitness, with further stratification by CVD risk factor burden. Lifetime risk for CVD death determined by the National Death Index was estimated for fitness levels measured at ages 45, 55, and 65 years, with non-CVD death as the competing event.Differences in fitness levels (low fitness vs. high fitness) were associated with marked differences in the lifetime risks for CVD death at each index age: age 45 years, 13.7% versus 3.4%; age 55 years, 34.2% versus 15.3%; and age 65 years, 35.6% versus 17.1%. These associations were strongest among persons with CVD risk factors.A single measurement of low fitness in mid-life was associated with higher lifetime risk for CVD death, particularly among persons with a high burden of CVD risk factors.
View details for DOI 10.1016/j.jacc.2010.10.056
View details for Web of Science ID 000289190600007
View details for PubMedID 21474041
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Cardiorespiratory Fitness and Classification of Risk of Cardiovascular Disease Mortality
CIRCULATION
2011; 123 (13): 1377-?
Abstract
Cardiorespiratory fitness (fitness) is associated with cardiovascular disease (CVD) mortality. However, the extent to which fitness improves risk classification when added to traditional risk factors is unclear.Fitness was measured by the Balke protocol in 66 371 subjects without prior CVD enrolled in the Cooper Center Longitudinal Study between 1970 and 2006; follow-up was extended through 2006. Cox proportional hazards models were used to estimate the risk of CVD mortality with a traditional risk factor model (age, sex, systolic blood pressure, diabetes mellitus, total cholesterol, and smoking) with and without the addition of fitness. The net reclassification improvement and integrated discrimination improvement were calculated at 10 and 25 years. Ten-year risk estimates for CVD mortality were categorized as <1%, 1% to <5%, and ≥5%, and 25-year risk estimates were categorized as <8%, 8% to 30%, and ≥30%. During a median follow-up period of 16 years, there were 1621 CVD deaths. The addition of fitness to the traditional risk factor model resulted in reclassification of 10.7% of the men, with significant net reclassification improvement at both 10 years (net reclassification improvement=0.121) and 25 years (net reclassification improvement=0.041) (P<0.001 for both). The integrated discrimination improvement was 0.010 at 10 years (P<0.001), and the relative integrated discrimination improvement was 29%. Similar findings were observed for women at 25 years.A single measurement of fitness significantly improves classification of both short-term (10-year) and long-term (25-year) risk for CVD mortality when added to traditional risk factors.
View details for DOI 10.1161/CIRCULATIONAHA.110.003236
View details for Web of Science ID 000289080500010
View details for PubMedID 21422392
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SENSOR-DRIVEN AUTOMATIC FEEDBACK ON MOBILE DEVICES FOR IMPROVING BEHAVIORAL MEASUREMENT AND INTERVENTION: DESIGN EXPERIENCES FROM TWO PILOT PROJECTS
SPRINGER. 2011: S147–S147
View details for Web of Science ID 000289297701062
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Long-Term Tracking of Physical Activity Behaviors in Women: The WIN Study
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2011; 43 (1): 165-170
Abstract
Interest lies in the prevalence of community-living women meeting the 2008 Department of Health and Human Services physical activity guidelines across time. The purpose was to report prevalence and stability of long-term (up to 125 wk) tracking of physical activity behaviors and to compare self-reported physical activity behaviors using different measures.The WIN study tracks nearly real-time physical activity behaviors in community-living women. At baseline, 918 women began weekly Internet reporting of physical activity behaviors, accessing a secure Internet site and answering eight questions about physical activity behaviors for the previous week. Measures included days and minutes of moderate, vigorous, walking, and strengthening activities, and pedometer steps were recorded weekly.Prevalence of meeting physical activity guidelines depended on the criterion used. Weekly averages across the surveillance period indicated 25% reported ≥150 min of moderate physical activity, 47% reported ≥75 min of vigorous physical activity, 57% reported ≥150 min of moderate-to-vigorous physical activity, 63% conducted ≥500 MET·min of physical activity, 15% reported ≥2 d of strengthening activities per week, and 39% reported ≥7500 steps per week. Alpha coefficients (≥0.97) indicated stable physical activity behaviors across all measures.Across reporting methods, it is estimated that approximately 50% or more of these community-living women engage in sufficient physical activity for health benefits weekly across long-term follow-up. Self-report physical activity behaviors are stable across long periods in these community-living women not participating in a specific physical activity intervention.
View details for DOI 10.1249/MSS.0b013e3181e61937
View details for Web of Science ID 000285410000021
View details for PubMedID 20473221
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Design of a Wearable Physical Activity Monitoring System using Mobile Phones and Accelerometers
33rd Annual International Conference of the IEEE Engineering-in-Medicine-and-Biology-Society (EMBS)
IEEE. 2011: 3636–3639
Abstract
This paper describes the motivation for, and overarching design of, an open-source hardware and software system to enable population-scale, longitudinal measurement of physical activity and sedentary behavior using common mobile phones. The "Wockets" data collection system permits researchers to collect raw motion data from participants who wear multiple small, comfortable sensors for 24 hours per day, including during sleep, and monitor data collection remotely.
View details for Web of Science ID 000298810002338
View details for PubMedID 22255127
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Glycemic Index, Glycemic Load, and Prevalence of the Metabolic Syndrome in the Cooper Center Longitudinal Study
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
2010; 110 (12): 1820-1829
Abstract
Previous research examining the relationships among glycemic index, glycemic load, and the metabolic syndrome has resulted in inconsistent findings. The objective of this study was to examine whether glycemic index and glycemic load are associated with prevalent metabolic syndrome and its components after adjustment for cardiorespiratory fitness, an objective measure of physical activity habitus.Cross-sectional study.Women (n=1,775) and men (n=9,137) who completed a comprehensive medical examination between October 1987 and March 1999, including maximal treadmill exercise test and 3-day dietary records at the Cooper Clinic, Dallas, TX.Metabolic syndrome and its components, defined by the revised Adult Treatment Panel III criteria.Multiple logistic regression models were used to estimate sex-specific odds ratios and 95% confidence intervals to evaluate the associations among glycemic index, glycemic load, and prevalent metabolic syndrome and its components, while adjusting for potential confounding variables.Prevalence of metabolic syndrome was 24% in men and 9% in women. A positive association across quintiles of glycemic index and metabolic syndrome, elevated triglycerides, and low high-density lipoprotein cholesterol (HDL-C) in men was observed in the fully adjusted model (P for trend<0.05). In women, glycemic index was positively associated with large waist girth, low HDL-C, and elevated triglycerides (P for trend<0.05 for all) after multivariate adjustment including cardiorespiratory fitness. Glycemic load was positively associated with elevated triglycerides and low HDL-C (P for trend<0.0001) and inversely associated with prevalence of large waist girth and elevated glucose (P for trend<0.0001) in men. Among women, glycemic load was positively associated with elevated triglycerides (P for trend=0.04) and low HDL-C (P for trend<0.0001) in the multivariate model including cardiorespiratory fitness.A lifestyle that includes a low glycemic diet can improve metabolic risk profiles in men and women. Prospective studies examining glycemic index, glycemic load, and metabolic syndrome that control for cardiorespiratory fitness are needed.
View details for DOI 10.1016/j.jada.2010.09.016
View details for Web of Science ID 000284918300011
View details for PubMedID 21111092
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Fitness and Reclassification of Risk for Cardiovascular Disease Mortality
LIPPINCOTT WILLIAMS & WILKINS. 2010
View details for Web of Science ID 000208231601280
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Objective Light-Intensity Physical Activity Associations With Rated Health in Older Adults
AMERICAN JOURNAL OF EPIDEMIOLOGY
2010; 172 (10): 1155-1165
Abstract
The extent to which light-intensity physical activity contributes to health in older adults is not well known. The authors examined associations between physical activity across the intensity spectrum (sedentary to vigorous) and health and well-being variables in older adults. Two 7-day assessments of accelerometry from 2005 to 2007 were collected 6 months apart in the observational Senior Neighborhood Quality of Life Study of adults aged >65 years in Baltimore, Maryland, and Seattle, Washington. Self-reported health and psychosocial variables (e.g., lower-extremity function, body weight, rated stress) were also collected. Physical activity based on existing accelerometer thresholds for moderate/vigorous, high-light, low-light, and sedentary categories were examined as correlates of physical health and psychosocial well-being in mixed-effects regression models. Participants (N = 862) were 75.4 (standard deviation, 6.8) years of age, 56% female, 71% white, and 58% overweight/obese. After adjustment for study covariates and time spent in moderate/vigorous physical activity and sedentary behavior, low-light and high-light physical activity were positively related to physical health (all P < 0.0001) and well-being (all P < 0.001). Additionally, replacing 30 minutes/day of sedentary time with equal amounts of low-light or high-light physical activity was associated with better physical health (all P < 0.0001). Objectively measured light-intensity physical activity is associated with physical health and well-being variables in older adults.
View details for DOI 10.1093/aje/kwq249
View details for Web of Science ID 000283918700008
View details for PubMedID 20843864
View details for PubMedCentralID PMC3004766
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A Tribute to Professor Jeremiah Morris: The Man Who Invented the Field of Physical Activity Epidemiology
ANNALS OF EPIDEMIOLOGY
2010; 20 (9): 651-660
View details for DOI 10.1016/j.annepidem.2010.06.001
View details for Web of Science ID 000281429400001
View details for PubMedID 20696405
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Longitudinal Examination of Age-Predicted Symptom-Limited Exercise Maximum HR
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2010; 42 (8): 1519-1527
Abstract
To estimate the association of age with maximal HR (MHR).Data were obtained from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants were black and white men and women aged 18-30 yr in 1985-1986 (year 0). A symptom-limited maximal graded exercise test was completed at years 0, 7, and 20 by 4969, 2583, and 2870 participants, respectively. After exclusion, 9622 eligible tests remained.In all 9622 tests, estimated MHR (eMHR, bpm) had a quadratic relation to age in the age range of 18-50 yr, eMHR = 179 + 0.29 x age - 0.011 x age(2). The age-MHR association was approximately linear in the restricted age ranges of consecutive tests. In 2215 people who completed tests of both years 0 and 7 (age range = 18-37 yr), eMHR = 189 - 0.35 x age; and in 1574 people who completed tests of both years 7 and 20 (age range = 25-50 yr), eMHR = 199 - 0.63 x age. In the lowest baseline body mass index (BMI) quartile, the rate of decline was 0.24 bpm*yr(-1) between years 0 and 7 and 0.51 bpm*yr(-1) between years 7 and 20, whereas in the highest baseline BMI quartile, there was a linear rate of decline of approximately 0.7 bpm.yr for the full age range of 18-50 yr.Clinicians making exercise prescriptions should be aware that the loss of symptom-limited MHR is much slower in young adulthood and more pronounced in later adulthood. In particular, MHR loss is very slow in those with the lowest BMI younger than 40 yr.
View details for DOI 10.1249/MSS.0b013e3181cf8242
View details for Web of Science ID 000279977500012
View details for PubMedID 20639723
View details for PubMedCentralID PMC2891874
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Risk of mortality increases with increasing number of abnormal non-ST parameters recorded during exercise testing
EUROPEAN JOURNAL OF CARDIOVASCULAR PREVENTION & REHABILITATION
2010; 17 (4): 462-468
Abstract
Abnormal non-ST segment treadmill parameters are associated with an increased mortality risk. Such measures include fitness, resting heart rate (HR), chronotropic incompetence, and HR recovery. However, whether there is an additive association among these parameters and the risk of mortality is unknown.Prospective observational registry study.We assessed the risk of cardiovascular and all-cause mortality in 25 642 individuals as an additive function of the number of these parameters. Abnormal responses were defined as follows: abnormal resting HR as a HR>or=80 bpm, abnormal fitness as an adjusted fitness level in the lowest 20%, chronotropic incompetence as an inability to achieve at least 80% of the predicted HR reserve, and abnormal HR recovery as an HR decline less than 12 bpm 1 min after exercise.During 7.2 years of follow-up, 392 participants died, with 94 from cardiovascular causes. Each parameter was significantly associated with all-cause and cardiovascular mortality (P<0.01) after adjustment for cardiovascular risk factors. There was a significant trend between both all-cause or cardiovascular mortality and the number of abnormal parameters (P<0.05).There is a continuum of risk as the number of abnormal parameters increases, suggesting that it may be important to determine their presence and number during exercise testing.
View details for DOI 10.1097/HJR.0b013e328336a10d
View details for Web of Science ID 000280550200013
View details for PubMedID 20084008
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Effects of Tai Chi and Western Exercise on Physical and Cognitive Functioning in Healthy Community-Dwelling Older Adults
JOURNAL OF AGING AND PHYSICAL ACTIVITY
2010; 18 (3): 261-279
Abstract
To compare the effects of Tai Chi (TC, n = 37) and Western exercise (WE, n = 39) with an attention-control group (C, n = 56) on physical and cognitive functioning in healthy adults age 69 +/- 5.8 yr, in a 2-phase randomized trial.TC and WE involved combined class and home-based protocols. Physical functioning included balance, strength, flexibility, and cardiorespiratory endurance. Cognitive functioning included semantic fluency and digit-span tests. Data were analyzed using intention-to-treat analysis.At 6 mo, WE had greater improvements in upper body flexibility (F = 4.67, p = .01) than TC and C. TC had greater improvements in balance (F = 3.36, p = .04) and a cognitive-function measure (F = 7.75, p < .001) than WE and C. The differential cognitive-function improvements observed in TC were maintained through 12 mo.The TC and WE interventions resulted in differential improvements in physical functioning among generally healthy older adults. TC led to improvement in an indicator of cognitive functioning that was maintained through 12 mo.
View details for Web of Science ID 000279052900002
View details for PubMedID 20651414
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Cardiorespiratory Fitness Levels Among US Adults 20-49 Years of Age: Findings From the 1999-2004 National Health and Nutrition Examination Survey
AMERICAN JOURNAL OF EPIDEMIOLOGY
2010; 171 (4): 426-435
Abstract
Data from the 1999-2004 National Health and Nutrition Examination Survey were used to describe the distribution of cardiorespiratory fitness and its association with obesity and leisure-time physical activity (LTPA) for adults 20-49 years of age without physical limitations or indications of cardiovascular disease. A sample of 7,437 adults aged 20-49 years were examined at a mobile examination center. Of 4,860 eligible for a submaximal treadmill test, 3,250 completed the test and were included in the analysis. The mean maximal oxygen uptake ( max) was estimated as 44.5, 42.8, and 42.2 mL/kg/minute for men 20-29, 30-39, and 40-49 years of age, respectively. For women, it was 36.5, 35.4, and 34.4 mL/kg/minute for the corresponding age groups. Non-Hispanic black women had lower fitness levels than did non-Hispanic white and Mexican-American women. Regardless of gender or race/ethnicity, people who were obese had a significantly lower estimated maximal oxygen uptake than did nonobese adults. Furthermore, a positive association between fitness level and LTPA participation was observed for both men and women. These results can be used to track future population assessments and to evaluate interventions. The differences in fitness status among population subgroups and by obesity status or LTPA can also be used to develop health policies and targeted educational campaigns.
View details for DOI 10.1093/aje/kwp412
View details for Web of Science ID 000274340900005
View details for PubMedID 20080809
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Validation of the Stanford Brief Activity Survey: Examining Psychological Factors and Physical Activity Levels in Older Adults
JOURNAL OF PHYSICAL ACTIVITY & HEALTH
2010; 7 (1): 87-94
Abstract
This study examined the construct validity and reliability of the new 2-item Stanford Brief Activity Survey (SBAS).Secondary analysis was conducted using data collected from the healthy older controls (n = 1023) enrolled in the Atherosclerotic Disease Vascular Function and Genetic Epidemiology (ADVANCE) study. Construct validity was examined by regression analyses to evaluate significant trends (P < or = .05) across the SBAS activity categories for the selected psychological health factors measured at baseline and year 2, adjusted for gender, ethnicity and education level. Test-retest reliability was performed using Spearman's rank correlation.At baseline, subjects were 66 +/- 2.8 years old, 38% female, 77% married, 61% retired, 24% college graduate, and 68% Caucasian. At baseline, lower self-reported stress, anxiety, depression, and cynical distrust, and higher self-reported mental and physical well-being were significantly associated with higher levels of physical activity (p trend < or = 0.01). These associations held at year 2. The test-retest reliability of the SBAS was statistically significant (r(s)= 0.62, P < .001).These results provide evidence of the construct validity and reliability of the SBAS in older adults. We also found a strong dose-response relationship between regular physical activity and psychological health in older adults, independent of gender, education level and ethnicity.
View details for Web of Science ID 000280737800012
View details for PubMedID 20231759
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The Breathe Easier through Weight Loss Lifestyle (BE WELL) Intervention: A randomized controlled trial
BMC PULMONARY MEDICINE
2010; 10
Abstract
Obesity and asthma have reached epidemic proportions in the US. Their concurrent rise over the last 30 years suggests that they may be connected. Numerous observational studies support a temporally-correct, dose-response relationship between body mass index (BMI) and incident asthma. Weight loss, either induced by surgery or caloric restriction, has been reported to improve asthma symptoms and lung function. Due to methodological shortcomings of previous studies, however, well-controlled trials are needed to investigate the efficacy of weight loss strategies to improve asthma control in obese individuals.BE WELL is a 2-arm parallel randomized clinical trial (RCT) of the efficacy of an evidence-based, comprehensive, behavioral weight loss intervention, focusing on diet, physical activity, and behavioral therapy, as adjunct therapy to usual care in the management of asthma in obese adults. Trial participants (n = 324) are patients aged 18 to 70 years who have suboptimally controlled, persistent asthma, BMI between 30.0 and 44.9 kg/m2, and who do not have serious comorbidities (e.g., diabetes, heart disease, stroke). The 12-month weight loss intervention to be studied is based on the principles of the highly successful Diabetes Prevention Program lifestyle intervention. Intervention participants will attend 13 weekly group sessions over a four-month period, followed by two monthly individual sessions, and will then receive individualized counseling primarily by phone, at least bi-monthly, for the remainder of the intervention. Follow-up assessment will occur at six and 12 months. The primary outcome variable is the overall score on the Juniper Asthma Control Questionnaire measured at 12 months. Secondary outcomes include lung function, asthma-specific and general quality of life, asthma medication use, asthma-related and total health care utilization. Potential mediators (e.g., weight loss and change in physical activity level and nutrient intake) and moderators (e.g., socio-demographic characteristics and comorbidities) of the intervention effects also will be examined.This RCT holds considerable potential for illuminating the nature of the obesity-asthma relationship and advancing current guidelines for treating obese adults with asthma, which may lead to reduced morbidity and mortality related to the comorbidity of the two disorders.NCT00901095.
View details for DOI 10.1186/1471-2466-10-16
View details for Web of Science ID 000208592700016
View details for PubMedCentralID PMC2860346
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The Breathe Easier through Weight Loss Lifestyle (BE WELL) Intervention: a randomized controlled trial.
BMC pulmonary medicine
2010; 10: 16-?
Abstract
Obesity and asthma have reached epidemic proportions in the US. Their concurrent rise over the last 30 years suggests that they may be connected. Numerous observational studies support a temporally-correct, dose-response relationship between body mass index (BMI) and incident asthma. Weight loss, either induced by surgery or caloric restriction, has been reported to improve asthma symptoms and lung function. Due to methodological shortcomings of previous studies, however, well-controlled trials are needed to investigate the efficacy of weight loss strategies to improve asthma control in obese individuals.BE WELL is a 2-arm parallel randomized clinical trial (RCT) of the efficacy of an evidence-based, comprehensive, behavioral weight loss intervention, focusing on diet, physical activity, and behavioral therapy, as adjunct therapy to usual care in the management of asthma in obese adults. Trial participants (n = 324) are patients aged 18 to 70 years who have suboptimally controlled, persistent asthma, BMI between 30.0 and 44.9 kg/m2, and who do not have serious comorbidities (e.g., diabetes, heart disease, stroke). The 12-month weight loss intervention to be studied is based on the principles of the highly successful Diabetes Prevention Program lifestyle intervention. Intervention participants will attend 13 weekly group sessions over a four-month period, followed by two monthly individual sessions, and will then receive individualized counseling primarily by phone, at least bi-monthly, for the remainder of the intervention. Follow-up assessment will occur at six and 12 months. The primary outcome variable is the overall score on the Juniper Asthma Control Questionnaire measured at 12 months. Secondary outcomes include lung function, asthma-specific and general quality of life, asthma medication use, asthma-related and total health care utilization. Potential mediators (e.g., weight loss and change in physical activity level and nutrient intake) and moderators (e.g., socio-demographic characteristics and comorbidities) of the intervention effects also will be examined.This RCT holds considerable potential for illuminating the nature of the obesity-asthma relationship and advancing current guidelines for treating obese adults with asthma, which may lead to reduced morbidity and mortality related to the comorbidity of the two disorders.NCT00901095.
View details for DOI 10.1186/1471-2466-10-16
View details for PubMedID 20334686
View details for PubMedCentralID PMC2860346
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Case Management to Reduce Risk of Cardiovascular Disease in a County Health Care System
ARCHIVES OF INTERNAL MEDICINE
2009; 169 (21): 1988-1995
Abstract
Case management (CM) is a systematic approach to supplement physician-centered efforts to prevent cardiovascular disease (CVD). Research is limited on its implementation and efficacy in low-income, ethnic minority populations.We conducted a randomized clinical trial to evaluate a nurse- and dietitian-led CM program for reducing major CVD risk factors in low-income, primarily ethnic minority patients in a county health care system, 63.0% of whom had type 2 diabetes mellitus. The primary outcome was the Framingham risk score (FRS).A total of 419 patients at elevated risk of CVD events were randomized and followed up for a mean of 16 months (81.4% retention). The mean FRS was significantly lower for the CM vs usual care group at follow-up (7.80 [95% confidence interval, 7.21-8.38] vs 8.93 [8.36-9.49]; P = .001) after adjusting for baseline FRS. This is equivalent to 5 fewer heart disease events per 1000 individuals per year attributable to the intervention or to 200 individuals receiving the intervention to prevent 1 event per year. The pattern of group differences in the FRS was similar in subgroups defined a priori by sex and ethnicity. The main driver of these differences was lowering the mean (SD) systolic (-4.2 [18.5] vs 2.6 [22.7] mm Hg; P = .003) and diastolic (-6.0 [11.6] vs -3.0 [11.7] mm Hg; P = .02) blood pressures for the CM vs usual care group.Nurse and dietitian CM targeting multifactor risk reduction can lead to modest improvements in CVD risk factors among high-risk patients in low-income, ethnic minority populations receiving care in county health clinics.clinicaltrials.gov Identifier: NCT00128687.
View details for Web of Science ID 000272036900010
View details for PubMedID 19933961
View details for PubMedCentralID PMC3000904
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Comparative Relation of General, Central, and Visceral Adiposity Measures for Coronary Artery Calcium in Subjects Without Previous Coronary Events
AMERICAN JOURNAL OF CARDIOLOGY
2009; 104 (7): 943-946
Abstract
It is unclear whether visceral obesity is largely responsible for an increased risk of coronary artery disease. In the present study, 1,054 men underwent coronary artery calcium (CAC) scoring and abdominal computed tomography. Risk factor information, body mass index, waist circumference, and waist-to-hip ratio were collected for all participants. The total fat, visceral fat, and subcutaneous fat areas were also quantified at the level of the umbilicus using computed tomography. We then investigated the association of these obesity parameters with the CAC score. Participants with a CAC score >10 had a larger waist circumference (97 +/- 12 vs 95 +/- 12 cm, p <0.001), a larger total fat area (434 cm(2), interquartile range 339 to 565, vs 415 cm(2), interquartile range 315 to 521; p = 0.005), a larger visceral fat area (200 cm(2), interquartile range 143 to 256, vs 175 cm(2), interquartile range 124 to 225; p <0.001), and a greater waist-to-hip ratio (0.93 +/- 0.07 vs 0.91 +/- 0.07, p <0.001) than those with a CAC score of < or =10. Those with a CAC score >10 also tended to have a greater body mass index and larger subcutaneous fat area. After adjusting for traditional cardiovascular risk factors, however, only a large waist circumference (odds ratio 1.5, 95% confidence interval 1.04 to 2.0), a high total fat area (odds ratio 1.5, 95% confidence interval 1.1 to 2.1), and a high waist-to-hip ratio (odds ratio 1.6, 95% confidence interval 1.2 to 2.3) remained significantly associated with a CAC score >10. In conclusion, the measures of central obesity were more strongly associated with the CAC score than either the parameters assessing overall obesity or other more direct measures of visceral adiposity. These findings suggest that the total amount of central obesity is more important than the relative distribution of visceral versus subcutaneous fat.
View details for DOI 10.1016/j.amjcard.2009.05.047
View details for Web of Science ID 000270537800013
View details for PubMedID 19766761
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Physical activity: Health outcomes and importance for public health policy
PREVENTIVE MEDICINE
2009; 49 (4): 280-282
Abstract
This manuscript presents a brief summary of the substantial data supporting an inverse relationship between the amount of habitual physical activity performed and a variety of negative health outcomes throughout the lifespan. It points out that despite these data a large segment of the US population remain insufficiently active resulting in a high population attributable risk for chronic disease due to inactivity. The accumulated data support the need for more comprehensive health promoting physical activity policies and programs, especially for the economically and socially disadvantaged and medically underserved.
View details for DOI 10.1016/j.ypmed.2009.05.002
View details for Web of Science ID 000271451700002
View details for PubMedID 19463850
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Use of Accelerometry to Measure Physical Activity in Older Adults at Risk for Mobility Disability
JOURNAL OF AGING AND PHYSICAL ACTIVITY
2008; 16 (4): 416-434
Abstract
The authors explored using the ActiGraph accelerometer to differentiate activity levels between participants in a physical activity (PA, n = 54) or "successful aging" (SA) program (n = 52). The relationship between a PA questionnaire for older adults (CHAMPS) and accelerometry variables was also determined. Individualized accelerometry-count thresholds (ThreshIND) measured during a 400-m walk were used to identify "meaningful activity." Participants then wore the ActiGraph for 7 days. Results indicated more activity bouts/day > or =10 min above ThreshIND in the PA group than in the SA group (1.1 +/- 2.0 vs 0.5 +/- 0.8, p = .05) and more activity counts/day above ThreshIND for the PA group (28,101 +/- 27,521) than for the SA group (17,234 +/- 15,620, p = .02). Correlations between activity counts/hr and CHAMPS ranged from .27 to .42, p < .01. The ActiGraph and ThreshIND might be useful for differentiating PA levels in older adults at risk for mobility disability.
View details for Web of Science ID 000260272700005
View details for PubMedID 19033603
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Multiple Wireless Accelerometers and Heart Rate Accurately Predict Energy Expenditure during Level Walking
LIPPINCOTT WILLIAMS & WILKINS. 2008: S62–S63
View details for Web of Science ID 000208070901240
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Stanford GEMS phase 2 obesity prevention trial for low-income African-American girls: Design and sample baseline characteristics
CONTEMPORARY CLINICAL TRIALS
2008; 29 (1): 56-69
Abstract
African-American girls and women are at high risk of obesity and its associated morbidities. Few studies have tested obesity prevention strategies specifically designed for African-American girls. This report describes the design and baseline findings of the Stanford GEMS (Girls health Enrichment Multi-site Studies) trial to test the effect of a two-year community- and family-based intervention to reduce weight gain in low-income, pre-adolescent African-American girls.Randomized controlled trial with measurements scheduled in girls' homes at baseline, 6, 12, 18 and 24 month post-randomization.Low-income areas of Oakland, CA.Eight, nine and ten year old African-American girls and their parents/caregivers.Girls are randomized to a culturally-tailored after-school dance program and a home/family-based intervention to reduce screen media use versus an information-based community health education Active-Placebo Comparison intervention. Interventions last for 2 years for each participant.Change in body mass index over the two-year study.Recruitment and enrollment successfully produced a predominately low-socioeconomic status sample. Two-hundred sixty one (261) families were randomized. One girl per family is randomly chosen for the analysis sample. Randomization produced comparable experimental groups with only a few statistically significant differences. The sample had a mean body mass index (BMI) at the 74 th percentile on the 2000 CDC BMI reference, and one-third of the analysis sample had a BMI at the 95th percentile or above. Average fasting total cholesterol and LDL cholesterol were above NCEP thresholds for borderline high classifications. Girls averaged low levels of moderate to vigorous physical activity, more than 3 h per day of screen media use, and diets high in energy from fat.The Stanford GEMS trial is testing the benefits of culturally-tailored after-school dance and screen-time reduction interventions for obesity prevention in low-income, pre-adolescent African-American girls.
View details for DOI 10.1016/j.cct.2007.04.007
View details for PubMedID 17600772
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Physical activity and public health - Updated recommendation for adults from the American college of sports medicine and the American heart association
CIRCULATION
2007; 116 (9): 1081-1093
Abstract
In 1995 the American College of Sports Medicine and the Centers for Disease Control and Prevention published national guidelines on Physical Activity and Public Health. The Committee on Exercise and Cardiac Rehabilitation of the American Heart Association endorsed and supported these recommendations. The purpose of the present report is to update and clarify the 1995 recommendations on the types and amounts of physical activity needed by healthy adults to improve and maintain health. Development of this document was by an expert panel of scientists, including physicians, epidemiologists, exercise scientists, and public health specialists. This panel reviewed advances in pertinent physiologic, epidemiologic, and clinical scientific data, including primary research articles and reviews published since the original recommendation was issued in 1995. Issues considered by the panel included new scientific evidence relating physical activity to health, physical activity recommendations by various organizations in the interim, and communications issues. Key points related to updating the physical activity recommendation were outlined and writing groups were formed. A draft manuscript was prepared and circulated for review to the expert panel as well as to outside experts. Comments were integrated into the final recommendation. PRIMARY RECOMMENDATION: To promote and maintain health, all healthy adults aged 18 to 65 yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. [I (A)] Combinations of moderate- and vigorous-intensity activity can be performed to meet this recommendation. [IIa (B)] For example, a person can meet the recommendation by walking briskly for 30 min twice during the week and then jogging for 20 min on two other days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by performing bouts each lasting 10 or more minutes. [I (B)] Vigorous-intensity activity is exemplified by jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every adult should perform activities that maintain or increase muscular strength and endurance a minimum of two days each week. [IIa (A)] Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity. [I (A)]
View details for DOI 10.1161/CIRCULATIONAHA.107.185649
View details for Web of Science ID 000249031100013
View details for PubMedID 17671237
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Physical activity and public health: Updated recommendation for adults from the American College of Sports Medicine and the American Heart Association
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2007; 39 (8): 1423-1434
Abstract
In 1995 the American College of Sports Medicine and the Centers for Disease Control and Prevention published national guidelines on Physical Activity and Public Health. The Committee on Exercise and Cardiac Rehabilitation of the American Heart Association endorsed and supported these recommendations. The purpose of the present report is to update and clarify the 1995 recommendations on the types and amounts of physical activity needed by healthy adults to improve and maintain health. Development of this document was by an expert panel of scientists, including physicians, epidemiologists, exercise scientists, and public health specialists. This panel reviewed advances in pertinent physiologic, epidemiologic, and clinical scientific data, including primary research articles and reviews published since the original recommendation was issued in 1995. Issues considered by the panel included new scientific evidence relating physical activity to health, physical activity recommendations by various organizations in the interim, and communications issues. Key points related to updating the physical activity recommendation were outlined and writing groups were formed. A draft manuscript was prepared and circulated for review to the expert panel as well as to outside experts. Comments were integrated into the final recommendation. PRIMARY RECOMMENDATION: To promote and maintain health, all healthy adults aged 18 to 65 yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. [I (A)] Combinations of moderate- and vigorous-intensity activity can be performed to meet this recommendation. [IIa (B)] For example, a person can meet the recommendation by walking briskly for 30 min twice during the week and then jogging for 20 min on two other days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by performing bouts each lasting 10 or more minutes. [I (B)] Vigorous-intensity activity is exemplified by jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every adult should perform activities that maintain or increase muscular strength and endurance a minimum of two days each week. [IIa (A)] Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity. [I (A)].
View details for DOI 10.1249/mss.0b013e3180616b27
View details for Web of Science ID 000248581500027
View details for PubMedID 17762377
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Resistance exercise in individuals with and without cardiovascular disease: 2007 update - A scientific statement from the American Heart Association Council on Clinical Cardiology and Council on Nutrition, Physical Activity, and Metabolism
CIRCULATION
2007; 116 (5): 572-584
Abstract
Prescribed and supervised resistance training (RT) enhances muscular strength and endurance, functional capacity and independence, and quality of life while reducing disability in persons with and without cardiovascular disease. These benefits have made RT an accepted component of programs for health and fitness. The American Heart Association recommendations describing the rationale for participation in and considerations for prescribing RT were published in 2000. This update provides current information regarding the (1) health benefits of RT, (2) impact of RT on the cardiovascular system structure and function, (3) role of RT in modifying cardiovascular disease risk factors, (4) benefits in selected populations, (5) process of medical evaluation for participation in RT, and (6) prescriptive methods. The purpose of this update is to provide clinicians with recommendations to facilitate the use of this valuable modality.
View details for DOI 10.1161/CIRCULATIONAHA.107.185214
View details for Web of Science ID 000248456000015
View details for PubMedID 17638929
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Clinical utility of the Stanford brief activity survey in men and women with early-onset coronary artery disease
46th Annual Conference on Cardiovascular Disease Epidemiology and Prevention
LIPPINCOTT WILLIAMS & WILKINS. 2007: 227–32
Abstract
To determine the utility of the Stanford Brief Activity Survey (SBAS) as a quick screening tool in a clinical population, where no other measure of physical activity was available.The SBAS was administered to 500 younger cases in the Atherosclerotic Disease Vascular Function and Genetic Epidemiology (ADVANCE) study, a case-control genetic association study, between December 2001 and January 2004. Younger cases in the ADVANCE study included men (<46 years old) and women (<56 years old) diagnosed with early-onset coronary artery disease. Frequency distributions of the SBAS and associations between SBAS activity categories and selected cardiovascular disease risk factors by sex were calculated.Subjects were 45.9 +/- 6.4 years old, 68% married, 61% women, 51% white, and 21% college graduates. Clinical diagnoses for early-onset coronary artery disease included 61% myocardial infarction, 23% coronary revascularization procedure, and 16% angina pectoris. In women, associations between all cardiovascular disease risk factors examined across SBAS categories were statistically significant (P trend < .01). In men, the associations across SBAS categories were statistically significant (P trend < .01), except for body mass index (P trend = .065). Adjustment for body mass index, age, ethnicity, and education with interactions by sex did not change the results.Subjects in the higher SBAS activity categories had more favorable cardiovascular disease risk profiles than did their less active counterparts, regardless of sex. The SBAS can be recommended for use in clinical populations providing immediate feedback on current physical activity level.
View details for Web of Science ID 000248736500007
View details for PubMedID 17667019
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A new feature: our scientific heritage.
Journal of physical activity & health
2007; 4 (3): 235-236
View details for PubMedID 17853530
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Tai Chi exercise and stroke rehabilitation
TOPICS IN STROKE REHABILITATION
2007; 14 (4): 9-22
Abstract
According to reported global estimates, 15 million people suffer from a stroke each year, resulting in 5.5 million deaths, with 5 million left permanently disabled. Typical disabilities following stroke include poor neuromuscular control, hemodynamic imbalance, and negative mood state. Tai Chi (TC) is associated with better balance, lower blood pressure, and improved mood, which are important for stroke survivors. An overview of the philosophy and principles of TC exercise is provided, followed by a literature review of reported TC studies examining balance, blood pressure, and mood. Finally, the potential application of TC exercise to stroke rehabilitation is discussed.
View details for DOI 10.1310/tsr1404-9
View details for Web of Science ID 000248527300003
View details for PubMedID 17698454
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Exercise and acute cardiovascular events placing the risks into perspective - A scientific statement from the American Heart Association council on nutrition, physical activity, and metabolism - In collaboration with the American college of sports medicine
CIRCULATION
2007; 115 (17): 2358-2368
Abstract
Habitual physical activity reduces coronary heart disease events, but vigorous activity can also acutely and transiently increase the risk of sudden cardiac death and acute myocardial infarction in susceptible persons. This scientific statement discusses the potential cardiovascular complications of exercise, their pathological substrate, and their incidence and suggests strategies to reduce these complications. Exercise-associated acute cardiac events generally occur in individuals with structural cardiac disease. Hereditary or congenital cardiovascular abnormalities are predominantly responsible for cardiac events among young individuals, whereas atherosclerotic disease is primarily responsible for these events in adults. The absolute rate of exercise-related sudden cardiac death varies with the prevalence of disease in the study population. The incidence of both acute myocardial infarction and sudden death is greatest in the habitually least physically active individuals. No strategies have been adequately studied to evaluate their ability to reduce exercise-related acute cardiovascular events. Maintaining physical fitness through regular physical activity may help to reduce events because a disproportionate number of events occur in least physically active subjects performing unaccustomed physical activity. Other strategies, such as screening patients before participation in exercise, excluding high-risk patients from certain activities, promptly evaluating possible prodromal symptoms, training fitness personnel for emergencies, and encouraging patients to avoid high-risk activities, appear prudent but have not been systematically evaluated.
View details for DOI 10.1161/CIRCULATIONAHA.107.181485
View details for Web of Science ID 000246122600016
View details for PubMedID 17468391
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Safety and efficacy of a ginkgo biloba-containing dietary supplement on cognitive function, quality of life, and platelet function in healthy, cognitively intact older adults
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
2007; 107 (3): 422-432
Abstract
To determine if a ginkgo biloba-containing supplement improves cognitive function and quality of life, alters primary hemostasis, and is safe in healthy, cognitively intact older adults.Four-month, randomized, double-blind, placebo-controlled parallel design.Ninety men and women (age range 65 to 84 years) were recruited to a university clinic. Eligibility included those without dementia or depression, not taking psychoactive medications or medications or supplements that alter hemostasis.Ninety subjects were randomly assigned to placebo or a ginkgo biloba-based supplement containing 160 mg ginkgo biloba, 68 mg gotu kola, and 180 mg decosahexaenoic acid per day for 4 months.Assessments included: six standardized cognitive function tests, the SF-36 Quality of Life questionnaire, the Platelet Function Analyzer-100 (Dade Behring, Eschbom, Germany), and the monitoring of adverse events.Baseline characteristics and study hypotheses were tested using analysis of covariance. Tests were two-tailed with a 0.05 significance level.Seventy-eight subjects (87%) completed both baseline and 4-month testing (n=36 in placebo group, n=42 in ginkgo biloba group). At baseline, the participants' cognitive function was above average. One of six cognitive tests indicated significant protocol differences at 4 months (P=0.03), favoring the placebo. There were no significant differences in quality of life, platelet function, or adverse events.These finding do not support the use of a ginkgo biloba-containing supplement for improving cognitive function or quality of life in cognitively intact, older, healthy adults. However, high baseline scores may have contributed to the null findings. The ginkgo biloba product seems safe and did not alter platelet function, though additional studies are needed to evaluate the interaction of varying doses of ginkgo biloba and ginkgo biloba-containing supplements with medications and supplements that alter hemostasis.
View details for DOI 10.1016/j.jada.2006.12.011
View details for Web of Science ID 000244551100016
View details for PubMedID 17324660
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Cardiorespiratory fitness and 20-year risk of dyslipidemia: The CARDIA fitness study
47th Annual Conference on Cardiovascular Disease Epidemiology and Prevention
LIPPINCOTT WILLIAMS & WILKINS. 2007: E249–E249
View details for Web of Science ID 000244482200181
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Twenty-year change in graded exercise treadmill test performance in young adults: CARDIA fitness study
47th Annual Conference on Cardiovascular Disease Epidemiology and Prevention
LIPPINCOTT WILLIAMS & WILKINS. 2007: E248–E248
View details for Web of Science ID 000244482200179
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Multifactor cardiovascular disease risk reduction in medically underserved, high-risk patients
AMERICAN JOURNAL OF CARDIOLOGY
2006; 98 (11): 1472-1479
Abstract
Few data exist on the effectiveness of cardiovascular disease (CVD) risk-reduction programs in patients with limited access to health care. The objective of this project was to evaluate a disease management approach to multifactor CVD risk reduction in patients with limited or no health insurance and low family income. Patients (n = 148) were recruited from not-for-profit or free clinics and hospitals and randomized to usual care or usual care plus team case management. Mean age was 59.3 years, 57% were women, 50% had less than a high school education, 57% were Hispanic, and 64% had no health insurance. All had > or =1 increased risk factor for CVD, and 24.5% had documented coronary artery disease. Follow-up measurements were obtained at 6 and 12 months. Primary outcomes were low-density lipoprotein cholesterol and systolic blood pressure. The disease management program was supervised by a physician, delivered by nurses and dietitians, and included comprehensive lifestyle changes and medications. Data were collected on 91% of patients at 12 months. Disease management produced clinically important decreases in selected risk factors compared with usual care, including systolic blood pressure (p <0.01) and low-density lipoprotein cholesterol (p <0.03). More patients with disease management than those with usual care moved from "high" and "very-high" risk to lower risk categories for selected risk factors. In conclusion, the disease management program had excellent retention and lower CVD risk factors and demonstrated the potential of such approaches for decreasing long-term disease burden in selected medically underserved populations.
View details for DOI 10.1016/j.amjcard.2006.06.049
View details for PubMedID 17126653
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Physical activity independently predicts increased MRI coronary vasodilation to nitroglycerin in older adults: The ADVANCE study
79th Annual Scientific Session of the American-Heart-Association
LIPPINCOTT WILLIAMS & WILKINS. 2006: 541–41
View details for Web of Science ID 000241792803450
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Validation of a new brief physical activity survey among men and women aged 60-69 years
45th Annual Conference on Cardiovascular Disease Epidemiology and Prevention
OXFORD UNIV PRESS INC. 2006: 598–606
Abstract
The Stanford Brief Activity Survey (SBAS), a new two-item physical activity survey, and the Stanford Seven-Day Physical Activity Recall (PAR) questionnaire were administered to men and women, aged 60-69 years, in the Atherosclerotic Disease VAscular functioN and genetiC Epidemiology (ADVANCE) Study. Frequency distributions of SBAS activity levels, as well as a receiver operating curve, were calculated to determine if the SBAS can detect recommended physical activity levels of 150 or more minutes/week at moderate or greater intensity, with PAR minutes/week. Data were collected between December 2001 and January 2004 from 1,010 participants (38% women) and recorded. Subjects were 65.8 (standard deviation: 2.8) years of age, 77% were married, 55% were retired, 23% were college graduates, and 68% were Caucasian. SBAS scores related significantly in an expected manner to PAR minutes/week (p < 0.01), energy expenditure (kcal/kg per day) (p < 0.01), and selected cardiovascular disease risk biomarkers (p < 0.01). The SBAS of physical activity at moderate intensity had a sensitivity of 0.73 and a specificity of 0.61. The SBAS is a quick assessment of the usual amount and intensity of physical activity that a person performs throughout the day. The SBAS needs further validation in other populations but demonstrated the potential of being a reasonably valid and inexpensive tool for quickly assessing habitual physical activity in large-scale epidemiology studies and clinical practice.
View details for DOI 10.1093/aje/kwj248
View details for Web of Science ID 000240588300011
View details for PubMedID 16840522
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Objectively measured physical activity and mortality in older adults
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
2006; 296 (2): 216-218
View details for Web of Science ID 000238946500028
View details for PubMedID 16835428
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Hemodynamic responses to a community-based Tai Chi exercise intervention in ethnic Chinese adults with cardiovascular disease risk factors.
European journal of cardiovascular nursing
2006; 5 (2): 165-174
Abstract
Cardiovascular disease (CVD) is the leading cause of death among older adults worldwide, including Europe, Asia, and North America. In the United States (US), CVD is also the leading cause of death among Asian-Americans. Physical activity has been shown to reduce CVD risk factors. Reduction in blood pressure (BP) in response to Tai Chi (TC) exercise in persons with CVD risk factors have been reported, though not in ethnic Chinese living in the US.Hemodynamic responses to a 12-week community-based TC exercise intervention among ethnic Chinese with CVD risk factors were examined.Quasi-experimental design. Ethnic Chinese > 45 years old with at least 1 major CVD risk factor, living in the San Francisco Bay Area, attended a TC intervention three times a week for 12 weeks. A 2-min step-in-place test assessed aerobic endurance. BP and heart rate were measured at rest, and within 1-min after the step-test. Data were collected at baseline, 6 and 12 weeks.A total of 39 subjects (69% women), 66 +/- 8.3 years old, with hypertension (92%), hypercholesteremia (49%), and/or diabetes (21%), and 1 current smoker participated. Adherence to the intervention was high (87%). Subjects were sedentary at baseline, though had a statistically significant improvement in aerobic endurance over-time (eta2 = 0.39). At baseline, the average BP at rest was 150/86, while BP in response to the step-test was 178/99. Clinically and statistically significant reductions in BP at rest (131/77), and in response to the step-test (164/82) were found over 12 weeks of TC (p < 0.01). No significant change in heart rate was observed.This innovative, culturally relevant, community-based 12-week TC exercise intervention, appealed to Chinese adults with CVD risk factors, with significant reductions in BP and improvement in aerobic endurance. Given the number of persons estimated to have HTN and other CVD risk factors, the identification of new approaches to improve health, combined with risk factor reduction is needed. This is particularly important, given the rise in HTN among adults in the US and the associated public health burden of HTN. TC has the potential to reduce expenditures associated with CVD by facilitating a lifestyle that promotes physical activity, while remaining a low-tech, low-cost alternative to exercise.
View details for PubMedID 16314148
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Change in perceived psychosocial status following a 12-week Tai Chi exercise programme
JOURNAL OF ADVANCED NURSING
2006; 54 (3): 313-329
Abstract
This paper reports a study to examine change in psychosocial status following a 12-week Tai Chi exercise intervention among ethnic Chinese people with cardiovascular disease risk factors living in the United States of America.Regular participation in physical activity is associated with protection against cardioavascular disease, and improvements in physical and psychological health. Increasing amounts of scientific evidence suggests that mind-body exercise, such as Tai Chi, are related to improvements in mental health, emotional well-being, and stress reduction. No prior study has examined the effect of a Tai Chi exercise intervention on psychosocial status among people with cardiovascular disease risk factors.This was a quasi-experimental study. Participants attended a 60-minute Tai Chi exercise class three times per week for 12 weeks. Data were collected at baseline, 6 and 12 weeks following the intervention. Psychosocial status was assessed using Chinese versions of Cohen's Perceived Stress Scale, Profile of Mood States, Multidimensional Scale of Perceived Social Support, and Tai Chi exercise self-efficacy.A total of 39 participants, on average 66-year-old (+/-8.3), married (85%), Cantonese-speaking (97%), immigrants participated. The majority were women (69%), with < or =12 years education (87%). Statistically significant improvements in all measures of psychosocial status were found (P < or = 0.05) following the intervention. Improvement in mood state (eta2 = 0.12), and reduction in perceived stress (eta2 = 0.13) were found. In addition, Tai Chi exercise statistically significantly increased self-efficacy to overcome barriers to Tai Chi (eta2 = 0.19), confidence to perform Tai Chi (eta2 = 0.27), and perceived social support (eta2 = 0.12).Tai Chi was a culturally appropriate mind-body exercise for these older adults, with statistically significant psychosocial benefits observed over 12-weeks. Further research examining Tai Chi exercise using a randomized clinical trial design with an attention-control group may reduce potential confounding effects, while exploring potential mechanisms underlying the relaxation response associated with mind-body exercise. In addition, future studies with people with other chronic illnesses in all ethnic groups are recommended to determine if similar benefits can be achieved.
View details for Web of Science ID 000237018700010
View details for PubMedID 16629916
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Improvement in balance, strength, and flexibility after 12 weeks of tai chi exercise in ethnic Chinese adults with cardiovascular disease risk factors
ALTERNATIVE THERAPIES IN HEALTH AND MEDICINE
2006; 12 (2): 50-58
Abstract
Declines in physical performance are associated with aging and chronic health conditions. Appropriate physical activity interventions can reverse functional limitations and help maintain independent living. Tai chi is a popular form of exercise in China among older adults.To determine whether tai chi improves balance, muscular strength and endurance, and flexibility over time.Repeated measures intervention; data collected at baseline, 6 weeks, and 12 weeks.Community center in the San Francisco Bay Area.Thirty-nine Chinese adults with at least 1 cardiovascular disease (CVD) risk factor.A 60-minute tai chi exercise class 3 times per week for 12 weeks.A battery of physical fitness measures specifically developed for older adults assessed balance, muscular strength and endurance, and flexibility.Subjects were 65.7 (+/- 8.3) years old, Cantonese-speaking (97%) immigrants, with 12 years or less of formal education (87%) and very low income (67%). Reported CVD risk factors were hypertension (92%), hypercholesteremia (49%), diabetes (21%), and 1 current smoker. Subjects were below the 50th percentile of fitness at baseline compared to age- and gender-specific normative US data. Statistically significant improvements were observed in all balance, muscular strength and endurance, and flexibility measures after 6 weeks, and they increased further after 12 weeks.Tai chi is a potent intervention that improved balance, upper- and lower-body muscular strength and endurance, and upper- and lower-body flexibility in these older Chinese adults. These findings provide important information for future community-based tai chi exercise programs and support current public health initiatives to reduce disability from chronic health conditions and enhance physical function in older adults.
View details for Web of Science ID 000236021100007
View details for PubMedID 16541997
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Assessing cardiorespiratory fitness without performing exercise testing
AMERICAN JOURNAL OF PREVENTIVE MEDICINE
2005; 29 (3): 185-193
Abstract
Low cardiorespiratory fitness (CRF) is associated with increased risk of chronic diseases and mortality; however, CRF assessment is usually not performed in many healthcare settings. The purpose of this study is to extend previous work on a non-exercise test model to predict CRF from health indicators that are easily obtained.Participants were men and women aged 20 to 70 years whose CRF level was quantified with a maximal or submaximal exercise test as part of the National Aeronautics and Space Administration/Johnson Space Center (NASA, n = 1863), Aerobics Center Longitudinal Study (ACLS, n = 46,190), or Allied Dunbar National Fitness Survey (ADNFS, n = 1706). Other variables included gender, age, body mass index, resting heart rate, and self-reported physical activity levels.All variables used in the multiple linear regression models were independently related to the CRF in each of the study cohorts. The multiple correlation coefficients obtained within NASA, ACLS, and ADNFS participants, respectively, were 0.81, 0.77, and 0.76. The standard error of estimate (SEE) was 1.45, 1.50, and 1.97 metabolic equivalents (METs) (1 MET = 3.5 ml O(2) uptake.kilograms of body mass(-1).minutes(-1)), respectively, for the NASA, ACLS, and ADNFS regression models. All regression models demonstrated a high level of cross-validity (0.72 < R < 0.80). The highest cross-validation coefficients were seen when the NASA regression model was applied to the ACLS and ADNFS cohorts (R = 0.76 and R = 0.75, respectively).This study suggests that CRF may be accurately estimated in adults from a non-exercise test model including gender, age, body mass index, resting heart rate, and self-reported physical activity.
View details for DOI 10.1016/j.amepre.2005.06.004
View details for Web of Science ID 000232187900004
View details for PubMedID 16168867
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Effect of treadmill testing and exercise training on self-efficacy in patients with heart failure.
European journal of cardiovascular nursing
2005; 4 (3): 215-219
Abstract
Self-efficacy is a person's confidence in being able to successfully perform a specific activity or behavior. Self-efficacy has been shown to influence exercise capacity in patients post myocardial infarction, but has not been fully explored in patients with heart failure (HF). This study examined the impact of performance of a single treadmill exercise test and participation in a 3-month program of walking and resistance exercise on self-efficacy in HF patients.24 patients were randomized to either a home-based walking and resistance exercise program or usual care for 3 months. Prior to enrollment into the exercise program all participants performed a single treadmill exercise test with respiratory gas analysis. Self-efficacy questionnaires were completed at 3 time points, 1) prior to performance of an exercise treadmill test; 2) immediately after completing an exercise test; and 3) at the end of a 3-month exercise program.Self-efficacy for walking (p=0.07), climbing (p=0.17), lifting (p=0.73) and general activity (p=0.15) did not improve after performance of a single treadmill exercise test and usual care. However, self-efficacy for walking increased after 3 months of a walking and resistance exercise program. (p=0.04).The findings from this study suggest that in patients with stable mild to moderate heart failure, self-efficacy is improved with participation in a home-based walking and endurance exercise program. Self-efficacy is not enhanced by performance of a single treadmill exercise test and usual care.
View details for PubMedID 15908277
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Effectiveness of therapeutic lifestyle changes in patients with hypertension, hyperlipidemia, and/or hyperglycemia
AMERICAN JOURNAL OF CARDIOLOGY
2004; 94 (12): 1558-1561
Abstract
In this prospective study of 2,390 ethnically diverse men and women, we evaluated the clinical effectiveness of 12 weeks of participation in a community-based lifestyle management program in helping patients who had hypertension, hyperlipidemia, and/or impaired fasting glucose or diabetes mellitus achieve goal risk factor levels without using pharmacotherapeutic agents. Although further research is warranted, the findings clearly show that many patients who have conventional risk factors for coronary heart disease can achieve goal levels without medications within 12 weeks of initiating therapeutic lifestyle changes and refute the notion that intensive lifestyle intervention is not worth the effort.
View details for DOI 10.1016/j.amjcard.2004.08.039
View details for Web of Science ID 000225781500018
View details for PubMedID 15589017
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Randomized trial of effect of alendronate continuation versus discontinuation in women with low BMD: Results from the Fracture Intervention Trial long-term extension
JOURNAL OF BONE AND MINERAL RESEARCH
2004; 19 (8): 1259-1269
Abstract
To determine the effects of continuation versus discontinuation of alendronate on BMD and markers of bone turnover, we conducted an extension trial in which 1099 older women who received alendronate in the FIT were re-randomized to alendronate or placebo. Compared with women who stopped alendronate, those continuing alendronate for 3 years maintained a higher BMD and greater reduction of bone turnover, showing benefit of continued treatment. However, among women who discontinued alendronate and took placebo in the extension, BMD remained higher, and reduction in bone turnover was greater than values at FIT baseline, showing persistence of alendronate's effects on bone.Prior trials including the Fracture Intervention Trial (FIT) have found that therapy with alendronate increases BMD and decreases fracture risk for up to 4 years in postmenopausal women with low BMD. However, it is uncertain whether further therapy with alendronate results in preservation or further gains in BMD and if skeletal effects of alendronate continue after treatment is stopped.We conducted a follow-up placebo-controlled extension trial to FIT (FIT long-term extension [FLEX]) in which 1099 women 60-86 years of age who were assigned to alendronate in FIT with an average duration of use of 5 years were re-randomized for an additional 5 years to alendronate or placebo. The results of a preplanned interim analysis at 3 years are reported herein. Participants were re-randomized to alendronate 10 mg/day (30%), alendronate 5 mg/day (30%), or placebo (40%). All participants were encouraged to take a calcium (500 mg/day) and vitamin D (250 IU/day) supplement. The primary outcome was change in total hip BMD. Secondary endpoints included change in lumbar spine BMD and change in markers of bone turnover (bone-specific alkaline phosphatase and urinary type I collagen cross-linked N-telopeptide).Among the women who had prior alendronate therapy in FIT, further therapy with alendronate (5 and 10 mg groups combined) for 3 years compared with placebo maintained BMD at the hip (2.0% difference; 95% CI, 1.6-2.5%) and further increased BMD at the spine (2.5% difference; 95% CI, 1.9-3. 1%). Markers of bone turnover increased among women discontinuing alendronate, whereas they remained stable in women continuing alendronate. Cumulative increases in BMD at the hip and spine and reductions in bone turnover from 8.6 years earlier at FIT baseline were greater for women continuing alendronate compared with those discontinuing alendronate. However, among women discontinuing alendronate and taking placebo in the extension, BMD remained higher and reduction in bone turnover was greater than values at FIT baseline.Compared with women who stopped alendronate after an average of 5 years, those continuing alendronate maintained a higher BMD and greater reduction of bone turnover, showing benefit of continued alendronate treatment on BMD and bone turnover. On discontinuation of alendronate therapy, rates of change in BMD at the hip and spine resumed at the background rate, but discontinuation did not result in either accelerated bone loss or a marked increase in bone turnover, showing persistence of alendronate's effects on bone. Data on the effect of continuation versus discontinuation on fracture risk are needed before making definitive recommendations regarding the optimal length of alendronate treatment.
View details for DOI 10.1359/JBMR.040326
View details for Web of Science ID 000222983000008
View details for PubMedID 15231012
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The prevention challenge - An overview of this supplement
AMERICAN JOURNAL OF PREVENTIVE MEDICINE
2003; 25 (3): 107-109
View details for DOI 10.1016/S0749-3797(03)00173-9
View details for Web of Science ID 000185803900001
View details for PubMedID 14552932
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Cardiovascular disease prevention and lifestyle interventions: effectiveness and efficacy.
journal of cardiovascular nursing
2003; 18 (4): 245-255
Abstract
Over the past half century scientific data support the strong relationship between the way a person or population lives and their risk for developing or dying from cardiovascular disease (CVD). While heredity can be a major factor for some people, their personal health habits and environmental/cultural exposure are more important factors. CVD is a multifactor process that is contributed to by a variety of biological and behavioral characteristics of the person including a number of well-established and emerging risk factors. Not smoking, being physically active, eating a heart healthy diet, staying reasonably lean, and avoiding major stress and depression are the major components of an effective CVD prevention program. For people at high risk of CVD, medications frequently need to be added to a healthy lifestyle to minimize their risk of a heart attack or stroke, particularly in persons with conditions such as hypertension, hypercholesterolemia, or hyperglycemia. Maintaining an effective CVD prevention program in technologically advanced societies cannot be achieved by many high-risk persons without effective and sustained support from a well-organized health care system. Nurse-provided or nurse-coordinated care management programs using an integrated or multifactor approach have been highly effective in reducing CVD morbidity and mortality of high-risk persons.
View details for PubMedID 14518600
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Physical activity and disease prevention: Past, present, and future - A personal perspective
EXERCISE AND SPORT SCIENCES REVIEWS
2003; 31 (3): 109-110
View details for Web of Science ID 000184222300001
View details for PubMedID 12882474
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Prospective investigation of autonomic nervous system function and the development of type 2 diabetes - The Atherosclerosis Risk in Communities study, 1987-1998
CIRCULATION
2003; 107 (17): 2190-2195
Abstract
Autonomic nervous system (ANS) dysfunction has been correlated with fasting insulin and glucose, independent of clinically diagnosed diabetes. We tested whether men and women (aged 45 to 64 years) from the Atherosclerosis Risk In Communities study (n=8185) with ANS dysfunction, estimated by high heart rate (HR) and low HR variability (HRV), were at increased risk for developing type 2 diabetes.Supine HR and HRV indices were measured for 2 minutes at baseline; indices were divided into quartiles for analyses. From 1987 to 1998 (mean follow-up 8.3 years), there were 1063 cases of incident diabetes. The relative risk (RR) of developing diabetes for participants with low-frequency (LF) power (0.04 to 0.15 Hz) HRV in the lowest quartile (<7.7 ms2) compared with the highest quartile (> or =38.9 ms2) was 1.2 (95% CI 1.0-1.4) after adjustment for age, race, sex, study center, education, alcohol drinking, current smoking, prevalent coronary heart disease, physical activity, and body mass index. Participants in the uppermost (>72.7 bpm) versus the lowest (< or =60.1 bpm) quartile of HR had a 60% increased risk (95% CI 33%-92%) of developing diabetes. Results were similar when the sample was restricted to participants with normal fasting glucose (glucose <6.1 mmol/L) at baseline (n=7192) or when adjusted for baseline glucose (HR quartile 4 versus quartile 1, RR=1.4, 95% CI 1.2-1.7).These findings suggest that ANS dysfunction may be associated with the development of diabetes in healthy adults.
View details for DOI 10.1161/01.CIR.0000066324.74807.95
View details for Web of Science ID 000182652500009
View details for PubMedID 12695289
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Smallest LDL particles are most strongly related to coronary disease progression in men
ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY
2003; 23 (2): 314-321
Abstract
LDLs include particle subclasses that have different mobilities on polyacrylamide gradient gels: LDL-I (27.2 to 28.5 nm), LDL-IIa (26.5 to 27.2 nm), LDL-IIb (25.6 to 26.5 nm), LDL-IIIa (24.7 to 25.6 nm), LDL-IIIb (24.2 to 24.7 nm), LDL-IVa (23.3 to 24.2 nm), and LDL-IVb (22.0 to 23.3 nm in diameter). We hypothesized that the association between smaller LDL particles and coronary artery disease (CAD) risk might involve specific LDL subclasses.Average 4-year onstudy lipoprotein measurements were compared with annualized rates of stenosis change from baseline to 4 years in 117 men with CAD. The percentages of total LDL and HDL occurring within individual subclasses were measured by gradient gel electrophoresis. Annual rate of stenosis change was related concordantly to onstudy averages of total cholesterol (P=0.04), triglycerides (P=0.05), VLDL mass (P=0.03), total/HDL cholesterol ratio (P=0.04), LDL-IVb (P=0.01), and HDL(3a) (P=0.02) and inversely to HDL(2)-mass (P=0.02) and HDL(2b) (P=0.03). The average annual rate in stenosis change was 6-fold more rapid in the fourth quartile of LDL-IVb (>or=5.2%) than in the first quartile (<2.5%, P=0.03). Stepwise multiple regression analysis showed that LDL-IVb was the single best predictor of stenosis change.LDL-IVb was the single best lipoprotein predictor of increased stenosis, an unexpected result, given that LDL-IVb represents only a minor fraction of total LDL.
View details for DOI 10.1161/01.ATV.0000053385.64132.2D
View details for Web of Science ID 000181165900028
View details for PubMedID 12588777
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Dance and reducing television viewing to prevent weight gain in African-American girls: the Stanford GEMS pilot study.
Ethnicity & disease
2003; 13 (1): S65-77
Abstract
To test the feasibility, acceptability, and potential efficacy of after-school dance classes and a family-based intervention to reduce television viewing, thereby reducing weight gain, among African-American girls.Twelve-week, 2-arm parallel group, randomized controlled trial.Low-income neighborhoods.Sixty-one 8-10-year-old African-American girls and their parents/guardians.The treatment intervention consisted of after-school dance classes at 3 community centers, and a 5-lesson intervention, delivered in participants' homes, and designed to reduce television, videotape, and video game use. The active control intervention consisted of disseminating newsletters and delivering health education lectures.Implementation and process measures, body mass index, waist circumference, physical activity measured by accelerometry, self-reported media use, and meals eaten with TV.Recruitment and retention goals were exceeded. High rates of participation were achieved for assessments and intervention activities, except where transportation was lacking. All interventions received high satisfaction ratings. At follow up, girls in the treatment group, as compared to the control group, exhibited trends toward lower body mass index (adjusted difference = -.32 kg/m2, 95% confidence interval [CI] -.77, .12; Cohen's d = .38 standard deviation units) and waist circumference (adjusted difference = -.63 cm, 95% CI -1.92, .67; d = .25); increased after-school physical activity (adjusted difference = 55.1 counts/minute, 95% CI -115.6, 225.8; d = .21); and reduced television, videotape, and video game use (adjusted difference = -4.96 hours/week, 95% CI -11.41, 1.49; d = .40). The treatment group reported significantly reduced household television viewing (d = .73, P = .007) and fewer dinners eaten while watching TV (adjusted difference = -1.60 meals/week, 95% CI -2.99, -.21; d = .59; P = .03). Treatment group girls also reported less concern about weight (d = .60; P = .03), and a trend toward improved school grades (d = .51; P = .07).This study confirmed the feasibility, acceptability, and potential efficacy of using dance classes and a family-based intervention to reduce television viewing, thereby reducing weight gain, in African-American girls.
View details for PubMedID 12713212
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A controlled pilot study of stress management training of elderly patients with congestive heart failure.
Preventive cardiology
2002; 5 (4): 168-72
Abstract
The purpose of this study was to evaluate the effect of stress management training on quality of life, functional capacity, and heart rate variability in elderly patients with New York Heart Association class I-III congestive heart failure (CHF). While substantial research exists on stress management training for patients with coronary heart disease, there are few data on the value of psychosocial training on patients with CHF. Thirty-three multiethnic patients (mean age, 66+/-9 years) were assigned through incomplete randomization to one of two treatment groups or a wait-listed control group. The 14 participants who completed the treatment attended eight training sessions during a 10-week period. The training consisted of 75-minute sessions adapted from the Freeze-Frame stress management program developed by the Institute of HeartMath. Subjects were assessed at baseline and again at the completion of the training. Depression, stress management, optimism, anxiety, emotional distress, and functional capacity were evaluated, as well as heart rate variability. Significant improvements (p<0.05) were noted in perceived stress, emotional distress, 6-minute walk, and depression, and positive trends were noted in each of the other psychosocial measures. The 24-hour heart rate variability showed no significant changes in autonomic tone. The authors noted that CHF patients were willing study participants and their emotional coping and functional capacity were enhanced. This program offers a simple and cost-effective way to augment medical management of CHF. Given the incompleteness of CHF medical management and the exploding interest in complementary medical intervention, it seems imperative that further work in psychosocial treatment be undertaken.
View details for PubMedID 12417824
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Effectiveness of three models for comprehensive cardiovascular disease risk reduction
AMERICAN JOURNAL OF CARDIOLOGY
2002; 89 (11): 1263-1268
Abstract
Cost and accessibility contribute to low participation rates in phase 2 cardiac rehabilitation programs in the United States. In this study, we compared the clinical effectiveness of 2 less costly and potentially more accessible approaches to cardiovascular risk reduction with that of a contemporary phase 2 cardiac rehabilitation program. Low- or moderate-risk patients (n = 155) with coronary artery disease (CAD) were randomly assigned to 12 weeks of participation in a contemporary phase 2 cardiac rehabilitation program (n = 52), a physician supervised, nurse-case-managed cardiovascular risk reduction program (n = 54), or a community-based cardiovascular risk reduction program administered by exercise physiologists guided by a computerized participant management system based on national clinical guidelines (n = 49). In all, 142 patients (91.6%) completed testing at baseline and after 12 weeks of intervention. For patients with abnormal (i.e., not at the goal level) baseline values, statistically significant (p < or =0.05) improvements were observed with all 3 interventions for multiple CAD risk factors. No statistically significant risk factor differences were observed among the 3 programs. For patients with a baseline maximal oxygen uptake < 7 metabolic equivalents, cardiorespiratory fitness increased to a greater degree in patients in the cardiac rehabilitation program and the community-based program versus the physician-supervised, nurse- case-managed program. These data have important implications for cost containment and increasing accessibility to clinically effective comprehensive cardiovascular risk reduction services in low- or moderate-risk patients with CAD.
View details for Web of Science ID 000175985300005
View details for PubMedID 12031725
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Effects of physical activity counseling in primary care - The activity counseling trial: A randomized controlled trial
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
2001; 286 (6): 677-687
Abstract
Physical activity is important for health, yet few studies have examined the effectiveness of physical activity patient counseling in primary care.To compare the effects of 2 physical activity counseling interventions with current recommended care and with each other in a primary care setting.The Activity Counseling Trial, a randomized controlled trial with recruitment in 1995-1997, with 24 months of follow-up.Eleven primary care facilities affiliated with 3 US clinical research centers.Volunteer sample of 395 female and 479 male inactive primary care patients aged 35 to 75 years without clinical cardiovascular disease.Participants were randomly assigned to 1 of 3 groups: advice (n = 292), which included physician advice and written educational materials (recommended care); assistance (n = 293), which included all the components received by the advice group plus interactive mail and behavioral counseling at physician visits; or counseling (n = 289), which included the assistance and advice group components plus regular telephone counseling and behavioral classes.Cardiorespiratory fitness, measured by maximal oxygen uptake (VO(2)max), and self-reported total physical activity, measured by a 7-day Physical Activity Recall, compared among the 3 groups and analyzed separately for men and women at 24 months.At 24 months, 91.4% of the sample had completed physical activity and 77.6% had completed cardiorespiratory fitness measurements. For women at 24 months, VO(2)max was significantly higher in the assistance group than in the advice group (mean difference, 80.7 mL/min; 99.2% confidence interval [CI], 8.1-153.2 mL/min) and in the counseling group than in the advice group (mean difference, 73.9 mL/min; 99.2% CI, 0.9-147.0 mL/min), with no difference between the counseling and assistance groups and no significant differences in reported total physical activity. For men, there were no significant between-group differences in cardiorespiratory fitness or total physical activity.Two patient counseling interventions differing in type and number of contacts were equally effective in women in improving cardiorespiratory fitness over 2 years compared with recommended care. In men, neither of the 2 counseling interventions was more effective than recommended care.
View details for Web of Science ID 000170271500023
View details for PubMedID 11495617
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CHAMPS physical activity questionnaire for older adults: outcomes for interventions
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2001; 33 (7): 1126-1141
Abstract
To evaluate effectively interventions to increase physical activity among older persons, reliable and valid measures of physical activity are required that can also detect the expected types of physical activity changes in this population. This paper describes a self-report physical activity questionnaire for older men and women, developed to evaluate the outcomes of the Community Healthy Activities Model Program for Seniors (CHAMPS), an intervention to increase physical activity.The questionnaire assesses weekly frequency and duration of various physical activities typically undertaken by older adults. We estimated caloric expenditure/wk expended in physical activity and created a summary frequency/wk measure. We calculated measures of each of these for: 1) activities of at least moderate intensity (MET value >/= 3.0); and 2) all specified physical activities, including those of light intensity. Six-month stability was estimated on participants not likely to change (assessment-only control group, physically active cohort). Several tests of construct validity were conducted, and sensitivity to change was analyzed based on response to the CHAMPS intervention.The sample (N = 249) comprised underactive persons (N = 173 from the CHAMPS trial) and active persons (N = 76). The sample was aged 65-90 yr (mean = 74, SD = 6); 64% were women, and 9% were minorities. Six-month stability ranged from 0.58 to 0.67, using intraclass correlation coefficients. Nearly all construct validity hypotheses were confirmed, though correlations were modest. All measures were sensitive to change (P < or = 0.01), with small to moderate effect sizes (0.38-0.64).The CHAMPS measure may be useful for evaluating the effectiveness of programs aimed at increasing levels of physical activity in older adults.
View details for Web of Science ID 000169660600010
View details for PubMedID 11445760
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What to look for in assessing responsiveness to exercise in a health context
Symposium on Dose-Response Issues Concerning Physical Activity and health
LIPPINCOTT WILLIAMS & WILKINS. 2001: S454–S458
Abstract
When attempting to assess responsiveness to habitual exercise in a health context, there is a wide range of issues that need to be addressed in order to provide science-based recommendations for use in evidence-informed health care delivery. Issues regarding responsiveness include characteristics of the exercise regimen or dose as well as characteristics of the response or effect.The exercise dose typically has been characterized by its type, intensity, session duration, and session frequency with the concepts of activity profile, activity volume, and accumulation over multiple bouts throughout the day recently added to these discussions. When establishing the dose for a designated outcome, specificity of the response in relation to exercise type needs to be considered. Understanding the role of intensity as a stimulus for change is critical because of the intensity-related biological responses to exercise, its role in exercise-induce medical complications, and the aversion many adults have to vigorous exercise. Receiving considerable attention is whether a higher intensity or greater volume of endurance-type exercise is more important in producing a variety of health-related benefits. To understand the potential role of accumulation of exercise, more information is needed on benefits derived from very short (< or = 5 min) bouts of exercise performed frequently as well as very long bouts (> or = 90 min) performed infrequently.When considering the response, it is important to establish the priority health outcomes, the relationship of the dose response for individual biological variables to the dose response for clinical outcomes, the basis for substantial interindividual variations in the response to a specific exercise dose, and the health benefit to health risk relationship for various doses of exercise. Scientific resolution of these issues will substantially facilitate the development and dissemination of appropriate guidelines for the use of exercise in promoting health.
View details for Web of Science ID 000169223200015
View details for PubMedID 11427771
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The effect of soy protein with or without isoflavones relative to milk protein on plasma lipids in hypercholesterolemic postmenopausal women
AMERICAN JOURNAL OF CLINICAL NUTRITION
2001; 73 (4): 728-735
Abstract
Clinical trial data and the results of a meta-analysis suggest a hypocholesterolemic effect of soy protein. The effect may be partially attributable to the isoflavones in soy. Few studies have examined the separate effects of soy protein and isoflavones.The objective of this study was to determine the effect of soy protein and isoflavones on plasma lipid concentrations in postmenopausal, moderately hypercholesterolemic women.This was a randomized, double-blind, placebo-controlled clinical trial with 3 treatment groups. After a 4-wk run-in phase during which the women consumed a milk protein supplement, the subjects were randomly assigned to 12 wk of dietary protein supplementation (42 g/d) with either a milk protein (Milk group) or 1 of 2 soy proteins containing either trace amounts of isoflavones (Soy- group) or 80 mg aglycone isoflavones (Soy+ group).LDL-cholesterol concentrations decreased more in the Soy+ group (n = 31) than in the Soy- group (n = 33) (0.38 compared with 0.09 mmol/L; P = 0.005), but neither of these changes was significantly different from the 0.26-mmol/L decrease observed in the Milk group (n = 30). The results for total cholesterol were similar to those for LDL cholesterol. There were no significant differences in HDL-cholesterol or triacylglycerol concentrations between the 3 groups.The difference in total- and LDL-cholesterol lowering between the 2 soy-protein supplements suggests an effect attributable to the isoflavone-containing fraction. However, the unexpected LDL-cholesterol lowering observed in the Milk group, and the fact that there was no significant difference between either soy group and the Milk group, suggests that changes may have been due to other factors related to participation in the study.
View details for Web of Science ID 000167716200010
View details for PubMedID 11273847
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[Sports, exercise and health. On the way into a new century].
Der Orthopade
2000; 29 (11): 930-935
Abstract
In most countries throughout the world, except those affected by the HIV-Aids epidemic, populations are increasing in size, rapidly getting older, and becoming more sedentary. This combination, along with the adoption of unhealthy habits such as cigarette smoking and consumption of an animal-based rather than a plant-based diet, will result in chronic degenerative diseases becoming the most common cause of disability and premature death throughout the world during the first twenty-five years of this new millennium. As more and more populations acquire the technology that reduces the need to exercise for transportation, occupation or maintaining a household, lack of activity quickly becomes a major risk for coronary heart disease, stroke, hypertension and noninsulin dependent diabetes mellitus. This lack of activity appears to contribute to other disorders such as osteoporosis and selected site-specific cancers. In older persons, inactivity can become a major reason for loss of physical independence and a reduction in their quality of life. Public health approaches will be needed to reverse this trend of increasing "hypokinetic" diseases as the computer/communication revolution becomes worldwide. These public health programs will need to be supported by government and corporate changes in policies that provide time, facilities and incentives for maintaining an appropriately active life-style. The goal should be for all adults to perform at least 30 minutes of moderate to vigorous intensity exercise on most days.
View details for PubMedID 11149277
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Compendium of Physical Activities: an update of activity codes and MET intensities
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2000; 32 (9): S498-S516
Abstract
We provide an updated version of the Compendium of Physical Activities, a coding scheme that classifies specific physical activity (PA) by rate of energy expenditure. It was developed to enhance the comparability of results across studies using self-reports of PA. The Compendium coding scheme links a five-digit code that describes physical activities by major headings (e.g., occupation, transportation, etc.) and specific activities within each major heading with its intensity, defined as the ratio of work metabolic rate to a standard resting metabolic rate (MET). Energy expenditure in MET-minutes, MET-hours, kcal, or kcal per kilogram body weight can be estimated for specific activities by type or MET intensity. Additions to the Compendium were obtained from studies describing daily PA patterns of adults and studies measuring the energy cost of specific physical activities in field settings. The updated version includes two new major headings of volunteer and religious activities, extends the number of specific activities from 477 to 605, and provides updated MET intensity levels for selected activities.
View details for Web of Science ID 000089257400009
View details for PubMedID 10993420
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Methodologic issues in measuring physical activity and physical fitness when evaluating the role of dietary supplements for physically active people
Workshop on Role of Dietary Supplements for Physically Active People
AMER SOC CLINICAL NUTRITION. 2000: 541S–550S
Abstract
Physical activity and physical fitness are complex entities comprising numerous diverse components that present a challenge in terms of accurate, reliable measurement. Physical activity can be classified by its mechanical (static or dynamic) or metabolic (aerobic or anaerobic) characteristics and its intensity (absolute or relative to the person's capacity). Habitual physical activity can be assessed by using a variety of questionnaires, diaries, or logs and by monitoring body movement or physiologic responses. Selection of a measurement method depends on the purpose of the evaluation, the nature of the study population, and the resources available. The various components of physical fitness can be assessed accurately in the laboratory and, in many cases, in the field by using a composite of performance tests. Most coaches and high-level athletes would accept as very beneficial a dietary supplement that would increase performance in a competitive event by even 3%; for example, lowering a runner's time of 3 min, 43 s in the 1500 m by 6.7 s. To establish that such small changes are caused by the dietary supplement requires carefully conducted research that involves randomized, placebo-controlled, double-blind studies designed to maximize statistical power. Statistical power can be increased by enlarging sample size, selecting tests with high reliability, selecting a potent but safe supplement, and maximizing adherence. Failure to design studies with adequate statistical power will produce results that are unreliable and will increase the likelihood that a true effect will be missed.
View details for Web of Science ID 000088634200009
View details for PubMedID 10919958
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Promoting physical activity: the new imperative for public health
HEALTH EDUCATION RESEARCH
2000; 15 (3): 367-376
Abstract
The aim of this essay is to provide an overview of initiatives designed to increase physical activity among different populations and in different settings, and to set the context for the major challenges that lie ahead. The decline in habitual physical activity with modernization, and the causal link between physical activity and health are briefly reviewed. The need to understand physical activity as a health behavior and examples of behavior change theories that have been applied to the promotion of physical activity are discussed. Diverse projects and campaigns in three countries, i.e. South Africa, Australia and the US, are highlighted. Common themes found in these physical activity initiatives include the development of a theory-driven research base, inclusion of behavioral and social scientists on multidisciplinary teams, and advocacy for environmental changes that promote physical activity. Within the next decade, research projects and national campaigns such as those described herein will yield important new findings on how to increase physical activity levels among targeted sectors of the population. The research agenda for the future includes development of both basic and applied research on physical activity, and the integration of theory across social, behavioral and biomedical disciplines.
View details for Web of Science ID 000087820300013
View details for PubMedID 10977383
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A review of mind/body therapies in the treatment of musculoskeletal disorders with implications for the elderly
ALTERNATIVE THERAPIES IN HEALTH AND MEDICINE
2000; 6 (2): 46-?
Abstract
A comprehensive, but not systematic, review of the research on complementary and alternative treatments, specifically mind/body techniques, on musculoskeletal disease was conducted at Stanford University. The goals of the review were to establish a comprehensive literature review and provide a rationale for future research carrying the theme of "successful aging."Computerized searches were conducted using MEDLINE, PsychInfo, Stanford Library, Dissertation Abstracts, Lexus-Nexus, the Internet as well as interviews conducted with practitioners and the elderly. Mind/body practices evaluated were: social support, cognitive-behavioral therapy, meditation, the placebo effect, imagery, visualization, spiritual/energy healing, music therapy, hypnosis, yoga, tai chi, and qigong. Studies published after 1990 were the priority, but when more recent literature was scarce, other controlled studies were included.Mind/body techniques were found to be efficacious primarily as complementary treatments for musculoskeletal disease and related disorders. Studies provided evidence for treatment efficacy but most apparent was the need for further controlled research.Reviewers found a dearth of randomized controlled research conducted in the US. There is a lack of studies with which to determine appropriate dosage and understand the mechanisms by which many of the practices work. Anecdotal evidence, some controlled research, clinical observation, as well as the cost effectiveness and lack of side effects of the mind/body treatments make further investigation a high priority.
View details for Web of Science ID 000085523000010
View details for PubMedID 10710803
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Impact of a home-based walking and resistance training program on quality of life in patients with heart failure
AMERICAN JOURNAL OF CARDIOLOGY
2000; 85 (3): 365-369
Abstract
Patients with heart failure (HF) often have profound activity limitations and diminished quality of life (QOL) due to symptoms of dyspnea and fatigue. Although recent studies demonstrate positive physiologic and psychological benefits of low to moderate intensity, supervised, aerobic exercise training performed 3 to 5 days/ week for 20 to 40 minutes' duration, in a monitored setting, the efficacy of a home-based exercise program combining endurance and resistance exercise on symptoms and QOL, are unknown. This randomized controlled study examined the efficacy, safety, and adherence rates of a 3-month home-based combined walking and resistance exercise program on symptoms and QOL in 40 women and men aged 30 to 76 years with New York Heart Association class II to III HF. Baseline and 3-month evaluations consisted of a chronic HF questionnaire to assess symptoms and QOL and exercise capacity by symptom-limited treadmill exercise test with respiratory gas analysis. The exercise intervention improved fatigue (p = 0.02), emotional function (p = 0.01), and mastery (p = 0.04). Overall exercise adherence was excellent (90%) and there were no reported adverse events. A moderate intensity home-based combined walking and resistance program for patients with class II to III HF is safe and effective in reducing symptoms and improving QOL.
View details for Web of Science ID 000084989800016
View details for PubMedID 11078308
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Comparative effects of two physical activity programs on measured and perceived physical functioning and other health-related quality of life outcomes in older adults
JOURNALS OF GERONTOLOGY SERIES A-BIOLOGICAL SCIENCES AND MEDICAL SCIENCES
2000; 55 (2): M74-M83
Abstract
Although inactivity is an important contributor to impaired functioning and disability with age, little is known concerning how improvements in physical functioning and well-being in older adults vary with the type of physical activity undertaken.One hundred three adults age 65 years and older, recruited via population-based methods, were randomized to 12 months of community-based, moderate-intensity endurance and strengthening exercises (Fit & Firm) or stretching and flexibility exercises (Stretch & Flex). A combination of class- and home-based exercise formats was used. Measured and self-rated physical performance along with perceived functioning and well-being were assessed pre- and postintervention.Fit & Firm subjects showed greater 12-month improvements in both measured and self-rated endurance and strength compared to Stretch & Flex subjects. Stretch & Flex subjects reported greater improvements in bodily pain, and Stretch & Flex men evidenced greater improvements in flexibility relative to Fit & Firm subjects. Although overall exercise adherence was high in both exercise conditions (approximately 80%), subjects in both conditions showed better adherence to the home- versus class-based portions of their exercise prescriptions.Community-based programs focusing on moderate-intensity endurance and strengthening exercises or flexibility exercises can be delivered through a combination of formats that result in improvement in important functional and well-being outcomes. This represents one of the first studies to report significant improvements in an important quality of life outcome-bodily pain-with a regular regimen of stretching and flexibility exercises in a community-based sample of older adults.
View details for Web of Science ID 000088044200014
View details for PubMedID 10737689
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Complementary and alternative medicine use among elderly persons: One-year analysis of a Blue Shield Medicare supplement
JOURNALS OF GERONTOLOGY SERIES A-BIOLOGICAL SCIENCES AND MEDICAL SCIENCES
2000; 55 (1): M4-M9
Abstract
Large scale surveys in the United States and abroad suggest that 35-60% of adults have used some form of complementary/alternative medicine (CAM). However, no studies to date have focused on predictors and patterns of CAM use among elderly persons.The population surveyed were Californians enrolled in a Medicare risk product that offers coverage for acupuncture and chiropractic care. Surveys were mailed to 1597 members in 1997 and responses received by 728 (51% response rate). Health risk assessment data were also obtained at baseline and 12-15 months following enrollment in the plan. Multiple logistic regression analyses were carried out to examine predictors of CAM use.Forty-one percent of seniors reported use of CAM. Herbs (24%), chiropractic (20%), massage (15%), and acupuncture (14%) were the most frequently cited therapies. CAM users tended to be younger, more educated, report either arthritis and/or depression/anxiety, not be hypertensive, engage in exercise, practice meditation, and make more frequent physician visits. Use of CAM was not associated with any observed changes in health status. Respondents also expressed considerable interest in receiving third-party coverage for CAM. Although 80% reported that they had received substantial benefit from their use of CAM, the majority (58%) did not discuss the use of these therapies with their medical doctor.Findings suggest that there is significant interest in and use of complementary/alternative medicine among elderly persons. These results suggest the importance of further research into the use and potential efficacy of these therapies within the senior population.
View details for Web of Science ID 000088044100012
View details for PubMedID 10719766
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A comprehensive and cost-effective preparticipation exam implemented on the World Wide Web
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1999; 31 (12): 1727-1740
Abstract
Mandatory preparticipation examinations (PPE) are labor intensive, offer little routine health maintenance and are poor predictors of future injury or illness. Our objective was to develop a new PPE for the Stanford University varsity athletes that improved both quality of primary and preventive care and physician time efficiency. This PPE is based on the annual submission, by each athlete, of a comprehensive medical history questionnaire that is then summarized in a two-page report for the examining physician. The questionnaire was developed through a search of MEDLINE from 1966 to 1997, review of PPE from 11 other institutions, and discussion with two experts from each of seven main content areas: medical and musculoskeletal history, eating, menstrual and sleep disorders, stress and health risk behaviors. Content validity was assessed by 10 sports medicine physicians and four epidemiologists. It was then programmed for the World Wide Web (http:// www.stanford.edu/dept/sportsmed/). The questionnaire demonstrated a 97 +/- 2% sensitivity in detecting positive responses requiring physician attention. Sixteen physicians administered the 1997/98 PPE; using the summary reports, 15 found improvement in their ability to provide overall medical care including health issues beyond clearance; 13 noted a decrease in time needed for each athlete exam. Over 90% of athletes who used the web site found it "easy" or "moderately easy" to access and complete. Initial assessment of this new PPE format shows good athlete compliance, improved exam efficiency and a strong increase in subjective physician satisfaction with the quality of screening and medical care provided. The data indicate a need for improvement of routine health maintenance in this population. The database offers opportunities to study trends, risk factors, and results of interventions.
View details for Web of Science ID 000084247100007
View details for PubMedID 10613422
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Current trends in the integration and reimbursement of complementary and alternative medicine by managed care organizations (MCOs) and insurance providers: 1998 update and cohort analysis
AMERICAN JOURNAL OF HEALTH PROMOTION
1999; 14 (2): 125-133
Abstract
To assess the status of managed care and insurance coverage of complementary and alternative medicine (CAM) and the integration of such services into conventional medicine.A literature review and information search was conducted to determine which insurers had special policies for CAM. Telephone interviews were conducted with a definitive sample of 9 out of 10 new MCOs or insurers identified in 1998 and a cohort of eight MCOs and insurers who responded both to the original survey in 1997 and again in 1998 to determine trends.This study constitutes the results of the second year of a 3-year ongoing survey. For 1998, 10 MCOs and insurance carriers initiated CAM coverage. Survey results are analyzed for these 10 new providers as well as the results of a cohort of eight insurers surveyed in both 1997 and 1998 to determine current trends. A majority of the insurers interviewed offer some coverage for the following: nutrition counseling, biofeedback, psychotherapy, acupuncture, preventive medicine, chiropractic, osteopathy, and physical therapy. All new MCOs and insurers said that market demand was their primary motivation for covering CAM. Factors determining whether insurers would offer coverage for additional therapies included potential cost-effectiveness, consumer interest, demonstrable clinical efficacy, and state mandates. Among the most common obstacles listed to incorporating CAM into mainstream health care were lack of research on efficacy, economics, ignorance about CAM, provider competition and division, and lack of standards of practice.Consumer demand for CAM is motivating more MCOs and insurance companies to assess the benefits of incorporating CAM. Outcomes studies for both conventional and CAM therapies are needed to help create a health care system based upon treatments that work, whether they are conventional, complementary, or alternative.
View details for Web of Science ID 000084532700009
View details for PubMedID 10724724
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Perceptions of physical fitness in patients with heart failure.
Progress in cardiovascular nursing
1999; 14 (3): 97-102
Abstract
This study examined the relationship between perceived physical condition and measured physical fitness and activity levels in 40 patients with moderate heart failure (HF). Self rated physical condition, physical activity, self efficacy, and quality of life were evaluated by self administered questionnaires. Functional capacity was examined by cardiopulmonary exercise testing and 6 minute walk test. We found that physical activity levels were low. Participation in moderate intensity recreational activity and physical fitness were associated with self efficacy. Perceived physical condition was associated with emotional well being and levels of energy and fatigue. We conclude that self efficacy may reflect physical condition and physical activity levels in this sample of HF patients and may be a simple indicator of physical ability. Because of the association between perceived physical condition and emotional well being, caution must be taken when using self reports of physical condition. Further study is needed to explore these relationships.
View details for PubMedID 10549047
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Seven year changes in physical fitness, physical activity, and lipid profile in the CARDIA study
ANNALS OF EPIDEMIOLOGY
1999; 9 (1): 25-33
Abstract
To relate seven year changes in physical fitness and physical activity in the young adult population to changes in the plasma lipid profile and to examine the influence of weight change on those relationships.The participants in this observational study were the 1777 black and white men and women, ages 18-30 at entry into the Coronary Artery Risk Development in Young Adults (CARDIA) cohort, who completed a symptom-limited graded treadmill exercise test and had an overnight fasting blood draw at both the Baseline (1985-86) and Year 7 (1992-93) exams. CARDIA, a longitudinal study of the relationships of lifestyle and physiological variables to the development of coronary heart disease risk factors, consists of population-based cohorts in Birmingham, Alabama, Minneapolis, Minnesota and Chicago, Illinois and a cohort recruited from the membership of a large, pre-paid health care plan, broadly representative of the population, in Oakland, California.All race/gender groups experienced mean decreases in physical fitness and self-reported physical activity and increases in weight. Decreased fitness was associated with decreased high density lipoprotein-cholesterol (HDL-C), and conversely, increased fitness was associated with increased HDL-C. The correlation coefficients of change in fitness with change in HDL-C ranged from 0.17 in white men and black women to 0.24 in white women (P < 0.001 for all race/gender groups). Change in fitness was minimally correlated with change in low density lipoprotein-cholesterol (LDL-C) in all groups (r ranged from -0.09 in black women to -0.20 in white women), triglycerides (TG) in men and white women (r ranged from -0.10 to -0.15), and total cholesterol (TC) in white men and women (r = -0.11 and -0.15, respectively). The magnitude of these correlations was further reduced with adjustment for weight change. Correlations between change in activity and change in lipid and lipoprotein values were generally weak or nonexistent, except for the suggestion of a small, direct relationship with change in HDL-C in black and white women (r = 0.14 and r = 0.11, respectively). All of the weight change adjusted correlations were essentially unaffected by further adjustment for baseline fitness or activity and other covariates.Decreased fitness during young adulthood is associated with unfavorable changes in lipid profile, explained mostly by increased weight. Lack of association between change in activity and change in lipid profile observed in this study may be due, in part, to imprecision of activity measurement.
View details for Web of Science ID 000077777300004
View details for PubMedID 9915606
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A review of the incorporation of complementary and alternative medicine by mainstream physicians
ARCHIVES OF INTERNAL MEDICINE
1998; 158 (21): 2303-2310
Abstract
Studies suggest that between 30% and 50% of the adult population in industrialized nations use some form of complementary and/or alternative medicine (CAM) to prevent or treat a variety of health-related problems.A comprehensive literature search identified 25 surveys conducted between 1982 and 1995 that examined the practices and beliefs of conventional physicians with regard to 5 of the more prominent CAM therapies: acupuncture, chiropractic, homeopathy, herbal medicine, and massage. Six studies were excluded owing to their methodological limitations.Across surveys, acupuncture had the highest rate of physician referral (43%) among the 5 CAM therapies, followed by chiropractic (40%) and massage (21%). Rates of CAM practice by conventional physicians varied from a low of 9% for homeopathy to a high of 19% for chiropractic and massage therapy. Approximately half of the surveyed physicians believed in the efficacy of acupuncture (51%), chiropractic (53%), and massage (48%), while fewer believed in the value of homeopathy (26%) and herbal approaches (13%).This review suggests that large numbers of physicians are either referring to or practicing some of the more prominent and well-known forms of CAM and that many physicians believe that these therapies are useful or efficacious. These data vary considerably across surveys, most likely because of regional differences and sampling methods, suggesting the need for more rigorous surveys using national, representative samples. Finally, outcomes studies are needed so that physicians can make decisions about the use of CAM based on scientific evidence of efficacy rather than on regional economics and cultural norms.
View details for Web of Science ID 000077045600002
View details for PubMedID 9827781
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Effects of diet and exercise in men and postmenopausal women with low levels of HDL cholesterol and high levels of LDL cholesterol
NEW ENGLAND JOURNAL OF MEDICINE
1998; 339 (1): 12-20
Abstract
Guidelines established by the National Cholesterol Education Program (NCEP) promote exercise and weight loss for the treatment of abnormal lipoprotein levels. Little is known, however, about the effects of exercise or the NCEP diet, which is moderately low in fat and cholesterol, in persons with lipoprotein levels that place them at high risk for coronary heart disease.We studied plasma lipoprotein levels in 180 postmenopausal women, 45 through 64 years of age, and 197 men, 30 through 64 years of age, who had low high-density lipoprotein (HDL) cholesterol levels (< or =59 mg per deciliter in women and < or =44 mg per deciliter in men) and moderately elevated levels of low-density lipoprotein (LDL) cholesterol (>125 mg per deciliter but <210 mg per deciliter in women and >125 mg per deciliter but <190 mg per deciliter in men). The subjects were randomly assigned to aerobic exercise, the NCEP Step 2 diet, or diet plus exercise, or to a control group, which received no intervention.Dietary intake of fat and cholesterol decreased during the one-year study (P<0.001), as did body weight, in women and men in either the diet group or the diet-plus-exercise group, as compared with the controls (P<0.001) and the exercise group (P<0.05), in which dietary intake and body weight were unchanged. Changes in HDL cholesterol and triglyceride levels and the ratio of total to HDL cholesterol did not differ significantly among the treatment groups, for subjects of either sex. The serum level of LDL cholesterol was significantly reduced among women (a decrease of 14.5+/-22.2 mg per deciliter) and men (a decrease of 20.0+/-17.3 mg per deciliter) in the diet-plus-exercise group, as compared with the control group (women had a decrease of 2.5+/-16.6 mg per deciliter, P<0.05; men had a decrease of 4.6+/-21.1 mg per deciliter, P<0.001). The reduction in LDL cholesterol in men in the diet-plus-exercise group was also significant as compared with that among the men in the exercise group (3.6+/-18.8 mg per deciliter, P<0.001). In contrast, changes in LDL cholesterol levels were not significant among the women (a decrease of 7.3+/-18.9 mg per deciliter) or the men (10.8+/-18.8 mg per deciliter) in the diet group, as compared with the controls.The NCEP Step 2 diet failed to lower LDL cholesterol levels in men or women with high-risk lipoprotein levels who did not engage in aerobic exercise. This finding highlights the importance of physical activity in the treatment of elevated LDL cholesterol levels.
View details for Web of Science ID 000074500000003
View details for PubMedID 9647874
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Clinical review 97 - Potential health benefits of dietary phytoestrogens: A review of the clinical, epidemiological, and mechanistic evidence
JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM
1998; 83 (7): 2223-2235
Abstract
Phytoestrogens represent a family of plant compounds that have been shown to have both estrogenic and antiestrogenic properties. A variety of these plant compounds and their mammalian metabolic products have been identified in various human body fluids and fall under two main categories: isoflavones and lignans. A wide range of commonly consumed foods contain appreciable amounts of these different phytoestrogens. For example, soy and flax products are particularly good sources of isoflavones and lignans, respectively. Accumulating evidence from molecular and cellular biology experiments, animal studies, and, to a limited extent, human clinical trials suggests that phytoestrogens may potentially confer health benefits related to cardiovascular diseases, cancer, osteoporosis, and menopausal symptoms. These potential health benefits are consistent with the epidemiological evidence that rates of heart disease, various cancers, osteoporotic fractures, and menopausal symptoms are more favorable among populations that consume plant-based diets, particularly among cultures with diets that are traditionally high in soy products. The evidence reviewed here will facilitate the identification of what is known in this area, the gaps that exist, and the future research that holds the most potential and promise.
View details for Web of Science ID 000074562200001
View details for PubMedID 9661587
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Activity Counseling Trial (ACT): rationale, design, and methods
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1998; 30 (7): 1097-1106
Abstract
The Activity Counseling Trial (ACT) is a multicenter, randomized controlled trial to evaluate the effectiveness of interventions to promote physical activity in the primary health care setting. ACT has recruited, evaluated, and randomized 874 men and women 35-75 yr of age who are patients of primary care physicians. Participants were assigned to one of three educational interventions that differ in amount of interpersonal contact and resources required: standard care control, staff-assisted intervention, or staff-counseling intervention. The study is designed to provide 90% power in both men and women to detect a 1.1 kcal.kg-1.day-1 difference in total daily energy expenditure between any two treatment groups, and over 90% power to detect a 7% increase in maximal oxygen uptake, the two primary outcomes. Primary analyses will compare study groups on mean outcome measures at 24 months post-randomization, be adjusted for the baseline value of the outcome measure and for multiple comparisons, and be conducted separately for men and women. Secondary outcomes include comparisons between interventions at 24 months of factors related to cardiovascular disease (blood lipids/lipoproteins, blood pressure, body composition, plasma insulin, fibrinogen, dietary intake, smoking, heart rate variability), psychosocial effect, and cost-effectiveness, and at 6 months for primary outcome measures. ACT is the first large-scale behavioral intervention study of physical activity counseling in a clinical setting, includes a generalizable sample of adult men and women and of clinical setting, and examines long-term (24 months) effects. ACT has the potential to make substantial contributions to the understanding of how to promote physical activity in the primary health care setting.
View details for Web of Science ID 000074599300012
View details for PubMedID 9662679
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A review of mind-body therapies in the treatment of cardiovascular disease Part 1: Implications for the elderly
ALTERNATIVE THERAPIES IN HEALTH AND MEDICINE
1998; 4 (3): 46-?
Abstract
A review of research on complementary and alternative treatments, specifically mind-body techniques, was conducted at Stanford University. The goals of the review were to establish a comprehensive literature review and to provide a rationale for future research concerning successful aging.Computerized searches were conducted using MEDLINE, PsychInfo, Stanford Library, Dissertation Abstracts, Lexus-Nexus, the Internet, and interviews conducted with practitioners. All studies since 1990 that examined mind-body treatments of cardiovascular disorders in the elderly were included. Mind-body practices evaluated were social support, cognitive-behavioral treatment, meditation, the placebo effect, hope, faith, imagery, spiritual healing, music therapy, hypnosis, yoga, t'ai chi, qigong and aikido. Studies conducted after 1990 were a priority, but when more recent literature was scarce, other studies using randomized, controlled trials were included.Mind-body techniques were found to be efficacious primarily as complementary and sometimes as stand-alone alternative treatments for cardiovascular disease-related conditions. Studies provided evidence for treatment efficacy, but the need for further controlled research was evident.Reviewers found only a handful of randomized, controlled research studies conducted in the United States. As a result, there is a lack of replicated studies with which to determine appropriate treatment dosage and the mechanisms by which many of the practices work. Compelling anecdotal evidence, the presence of some controlled research, overall cost effectiveness, and the lack of side effects resulting from mind-body treatments make further investigation a high priority.
View details for Web of Science ID 000077175500017
View details for PubMedID 9581321
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Seven-year change in graded exercise treadmill test performance in young adults in the CARDIA study
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1998; 30 (3): 427-433
Abstract
Most studies of physical fitness change have been relatively small, not population-based, and lacking in women and nonwhites. The purpose of this analysis was to evaluate the 7-yr change in physical fitness in a biracial (black and white) population of young men and women.We evaluated change in exercise treadmill test performance in a biracial (black and white) population of 1,962 young adults, ages 18-30 yr at baseline, who completed symptom-limited graded exercise treadmill tests at the baseline (1985-1986) and year 7 (1992-1993) examinations of the CARDIA study.Mean test duration decreased 58 s (9.5%) over 7 yr (black men, 13.6% decrease, white men, 7.4%; black women, 11.1%; white women, 7.0%). Mean time to heart rate 130 (WL130), a measure of submaximal performance, decreased 31 s (11.3%) (black men, 16.9%; white men, 10.0%; black women, 12.3%; white women, 6.1%). Baseline body mass index (BMI) and physical activity were not statistically significant predictors of test duration change in any race-gender group, but change in BMI and activity were. Seven-year weight gain >20 lbs (31% of cohort) was associated with a large decrease in fitness (18.5% decrease in mean duration, 21.8% decrease in WL130).These data suggest that fitness declines during young adulthood in blacks and whites and that fitness changes are related to changes in weight and physical activity.
View details for Web of Science ID 000072380100014
View details for PubMedID 9526890
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Current trends in the integration and reimbursement of complementary and alternative medicine by managed care, insurance carriers, and hospital providers
AMERICAN JOURNAL OF HEALTH PROMOTION
1997; 12 (2): 112-122
Abstract
To assess the status of managed care and insurance coverage of complementary and alternative medicine (CAM) and the integration of such services offered by hospitals.A literature review and information search was conducted to determine which insurers had special policies for CAM and which hospitals were offering CAM. Telephone interviews were conducted with a definitive sample of 18 insurers and a representative subsample of seven hospitals.A majority of the insurers interviewed offered some coverage for the following: nutrition counseling, biofeedback, psychotherapy, acupuncture, preventive medicine, chiropractic, osteopathy, and physical therapy. Twelve insurers said that market demand was their primary motivation for covering CAM. Factors determining whether insurers would offer coverage for additional therapies included potential cost-effectiveness based on consumer interest, demonstrable clinical efficacy, and state mandates. Some hospitals are also responding to consumer interest in CAM, although hospitals can only offer CAM therapies for which local, licensed practitioners are available. Among the most common obstacles listed to incorporating CAM into mainstream health care were lack of research on efficacy, economics, ignorance about CAM, provider competition and division, and lack of standards of practice.Consumer demand for CAM is motivating more insurers and hospitals to assess the benefits of incorporating CAM. Outcomes studies for both allopathic and CAM therapies are needed to help create a health care system based upon treatments that work, whether they are mainstream, complementary, or alternative.
View details for Web of Science ID 000168676600008
View details for PubMedID 10174663
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Comprehensive cardiovascular disease risk reduction in a cardiac rehabilitation setting.
American journal of cardiology
1997; 80 (8B): 69H-73H
Abstract
Cardiac rehabilitation combines prescriptive exercise training with coronary artery disease (CAD) risk factor modification in patients with established CAD. As such, cardiac rehabilitation programs are ideally positioned to assume a pivotal role in the rendering of many components of comprehensive cardiovascular disease risk reduction in a secondary prevention setting. However, the extent to which traditional cardiac rehabilitation programs can successfully accomplish this goal is limited by low participation rates, inadequate emphasis on many of the essential aspects of secondary prevention, and lack of long-term follow-up of patients. To overcome these deficiencies, cardiac rehabilitation programs should evolve into cardiovascular risk reduction programs by implementing approaches that have been shown to be effective in randomized clinical trials. In this manuscript we describe one such approach, based on the Stanford Coronary Risk Intervention Project, which has been implemented in > 1,000 patients. Key components of this physician-supervised, nurse case-manager model include: (1) initial evaluation and risk assessment; (2) identification of specific goals for each CAD risk factor; (3) formulation and implementation of an individualized treatment plan that includes lifestyle modification and pharmacologic interventions for accomplishing specific risk reduction goals; (4) long-term follow-up to enhance compliance and revise the treatment plan as indicated; and (5) a mechanism for outcomes based long-term assessment of each patient.
View details for PubMedID 9373003
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Sleep quality in older adults: Effects of exercise training and influence of sunlight exposure - Reply
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
1997; 277 (13): 1034-1035
View details for Web of Science ID A1997WQ08900014
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Moderate-intensity exercise and self-rated quality of sleep in older adults - A randomized controlled trial
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
1997; 277 (1): 32-37
Abstract
To determine the effects of moderate-intensity exercise training on self-rated (subjective) sleep quality among healthy, sedentary older adults reporting moderate sleep complaints.Randomized controlled trial of 16 weeks' duration.General community.Volunteer sample of 29 women and 14 men (of 67 eligible subjects) aged 50 to 76 years who were sedentary, free of cardiovascular disease, and reported moderate sleep complaints. No participant was withdrawn for adverse effects.Randomized to 16 weeks of community-based, moderate-intensity exercise training or to a wait-listed control condition. Exercise consisted primarily of four 30- to 40-minute endurance training sessions (low-impact aerobics; brisk walking) prescribed per week at 60% to 75% of heart rate reserve based on peak treadmill exercise heart rate.Pittsburgh Sleep Quality Index (PSQI).Compared with controls (C), subjects in the exercise training condition (E) showed significant improvement in the PSQI global sleep score at 16 weeks (baseline and posttest values in mean [SD] for C=8.93 [3.1] and 8.8 [2.6]; baseline and posttest values for E=8.7 [3.0] and 5.4 [2.8]; mean posttest difference between conditions=3.4; P<.001; 95% confidence interval, 1.9-5.4), as well as in the sleep parameters of rated sleep quality, sleep-onset latency (baseline and posttest values for C=26.1 [20.0] and 23.8 [15.3]; for E=28.4 [20.2] and 14.6 [13.0]; net improvement=11.5 minutes), and sleep duration baseline and posttest scores for C=5.8 [1.1] and 6.0 [1.0]; for E=6.0 [1.1] and 6.8 [1.2]; net improvement=42 minutes) assessed via PSQI and sleep diaries (P=.05).Older adults with moderate sleep complaints can improve self-rated sleep quality by initiating a regular moderate-intensity exercise program.
View details for Web of Science ID A1997VZ76700026
View details for PubMedID 8980207
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Randomised trial of effect of alendronate on risk of fracture in women with existing vertebral fractures
LANCET
1996; 348 (9041): 1535-1541
Abstract
Previous studies have shown that alendronate can increase bone mineral density (BMD) and prevent radiographically defined (morphometric) vertebral fractures. The Fracture Intervention Trial aimed to investigate the effect of alendronate on the risk of morphometric as well as clinically evident fractures in postmenopausal women with low bone mass.Women aged 55-81 with low femoral-neck BMD were enrolled in two study groups based on presence or absence of an existing vertebral fracture. Results for women with at least one vertebral fracture at baseline are reported here. 2027 women were randomly assigned placebo (1005) or alendronate (1022) and followed up for 36 months. The dose of alendronate (initially 5 mg daily) was increased (to 10 mg daily) at 24 months, with maintenance of the double blind. Lateral spine radiography was done at baseline and at 24 and 36 months. New vertebral fractures, the primary endpoint, were defined by morphometry as a decrease of 20% (and at least 4 mm) in at least one vertebral height between the baseline and latest follow-up radiograph. Non-spine clinical fractures were confirmed by radiographic reports. New symptomatic vertebral fractures were based on self-report and confirmed by radiography.Follow-up radiographs were obtained for 1946 women (98% of surviving participants). 78 (8.0%) of women in the alendronate group had one or more new morphometric vertebral fractures compared with 145 (15.0%) in the placebo group (relative risk 0.53 [95% Cl 0.41-0.68]). For clinically apparent vertebral fractures, the corresponding numbers were 23 (2.3%) alendronate and 50 (5.0%) placebo (relative hazard 0.45 [0.27-0.72]). The risk of any clinical fracture, the main secondary endpoint, was lower in the alendronate than in the placebo group (139 [13.6%] vs 183 [18.2%]; relative hazard 0.72 [0.58-0.90]). The relative hazards for hip fracture and wrist fracture for alendronate versus placebo were 0.49 (0.23-0.99) and 0.52 (0.31-0.87). There was no significant difference between the groups in numbers of adverse experiences, including upper-gastrointestinal disorders.We conclude that among women with low bone mass and existing vertebral fractures, alendronate is well tolerated and substantially reduces the frequency of morphometric and clinical vertebral fractures, as well as other clinical fractures.
View details for Web of Science ID A1996VX02300007
View details for PubMedID 8950879
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Predominance of dense low-density lipoprotein particles predicts angiographic benefit of therapy in the stanford coronary risk intervention project
CIRCULATION
1996; 94 (9): 2146-2153
Abstract
LDL particles differ in size and density. Individuals with LDL profiles that peak in relatively small, dense particles have been reported to be at increased risk of coronary artery disease. We hypothesized that response to coronary disease therapy in such individuals might differ from response in individuals whose profiles peak in larger, more buoyant LDL. We examined this hypothesis in the Stanford Coronary Risk Intervention Project, an angiographic trial that compared multifactorial risk-reduction intervention with the usual care of physicians.For 213 men, a bimodal frequency distribution of peak LDL density (g/mL) determined by analytical ultracentrifugation was used to classify baseline LDL profiles as "buoyant mode" (density < or = 1.0378) or "dense mode" (density > 1.0378). Coronary disease progression after 4 years was assessed by rates of change (mm/y, negative when arteries narrow) of minimum artery diameter. Rates for buoyant-mode subjects were -0.038 +/- 0.007 (mean +/- SEM) in usual care (n = 65) and -0.039 +/- 0.010 in intervention (n = 56; P = .6). Rates for dense-mode subjects were -0.054 +/- 0.012 in usual care (n = 51) and -0.008 +/- 0.009 in intervention (n = 41, P = .007). Lipid changes did not account for this difference in angiographic response.Different types of LDL profile may predict different-responses to specific therapies, perhaps because metabolic processes determine both LDL profiles and responses to therapies.
View details for Web of Science ID A1996VN75400020
View details for PubMedID 8901665
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Physical activity, sport, and health: Toward the next century
1996 International Pre-Olympic Scientific Congress on Physical Activity, Sport, and Health
AMER ALLIANCE HEALTH PHYS EDUC REC & DANCE. 1996: S37–S47
View details for Web of Science ID A1996VP68700005
View details for PubMedID 8902907
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Effect of community health education on physical activity knowledge, attitudes, and behavior - The Stanford Five-City Project
AMERICAN JOURNAL OF EPIDEMIOLOGY
1996; 144 (3): 264-274
Abstract
The authors studied the effectiveness of community-wide health education on physical activity knowledge, attitudes, self-efficacy, and behavior. Random samples of residents aged 18-74 years who lived in four central California cities (baseline, n = 1,056 men and 1,183 women) were evaluated in 1979-1980 and approximately every 2 years thereafter to obtain four independent samples. Moreover, every subject in the initial independent samples was asked to return for follow-up every 2 years thereafter; subjects who completed all four examinations constituted the cohort sample (n = 408 men and 499 women). Two medium-sized cities received health education and two similarly sized cities served as controls. Results indicated little consistent evidence of a treatment effect on physical activity knowledge, attitudes, or self-efficacy in either men or women. Among physical activity measures, there was an indication of a positive treatment effect for men in the independent samples for estimated daily energy expenditure and percent participation in vigorous activities (p < 0.01), and for women in the independent (p = 0.014) and cohort (p < 0.01) samples for engagement in the number of moderate activities. These results underscore the need for development of more effective interventions to change physical activity than is provided by a broad-based, community-wide health education program and for more sensitive and reliable measures of knowledge, attitudes, and behavior with regard to physical activity.
View details for Web of Science ID A1996UZ75400007
View details for PubMedID 8686695
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Television viewing and cardiovascular risk factors in young adults: The CARDIA study
ANNALS OF EPIDEMIOLOGY
1996; 6 (2): 154-159
Abstract
Cross-sectional associations between self-reported hours of television (TV) viewing per day and cardiovascular risk factors were assessed in a biracial (black and white) study population of 4280 men and women, ages 23 to 35 years, undergoing the year-5 follow-up examination for the Cardiovascular Risk Development in Young Adults (CARDIA) study in 1990 to 1991. Number of hours of TV viewing per day was higher in blacks than in whites and was inversely associated with education and income. Relative to "light" TV viewers (0 to 1 h/d), "heavy" TV viewers (> or = 4 h/d) had a higher prevalence (P < 0.05) of obesity, smoking, and high hostility score in all race/gender groups, and of physical inactivity in all groups except black men. Among whites, "heavy" TV viewers had higher depression scores, and among blacks, reported more alcohol use. TV viewing was not associated with hypertension and lipid abnormalities. Heavy TV viewing is a modifiable behavior that is associated with increased prevalence of several cardiovascular risk factors.
View details for Web of Science ID A1996UC78000009
View details for PubMedID 8775596
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Predictors of physical activity in patients with chronic heart failure secondary to either ischemic or idiopathic dilated cardiomyopathy
AMERICAN JOURNAL OF CARDIOLOGY
1996; 77 (2): 159-163
Abstract
To identify predictors of physical activity levels in patients with chronic heart failure, 43 patients, aged 33 to 91 years, who had well-compensated heart failure were asked to perform a symptom-limited exercise treadmill test and to complete activity logs for 2 consecutive days while wearing an ambulatory heart rate activity monitor. Activity logs included information on the type of activity, duration, rating of perceived exertion, symptoms experienced, and the intensity of symptoms. Subjects also completed the Duke Activity Status Index, a brief self-administered questionnaire that assesses physical functioning, and a self-efficacy for general activity questionnaire. Simultaneous multiple regression analysis was used to predict physical activity levels from a model that included: personal variables of physical fitness (peak oxygen consumption); knowledge, attitudes, and beliefs including self-efficacy for general activity, and rating of perceived exertion during daily activity; and environmental factors such as social support (marital status). The overall model explained 38% of the variance (p < 0.001). Self-efficacy (p = 0.015) was the strongest predictor of physical activity in this group. From this initial descriptive study, we conclude that self-efficacy is a better predictor of performance of physical activity than measures of physical fitness or rating of perceived exertion during activity. Additional studies are needed to examine other behavioral and physiologic mediators as well as behavioral strategies that may be used to increase participation in physical activity programs. Particularly promising are strategies to enhance self-efficacy for exercise.
View details for Web of Science ID A1996TQ96300010
View details for PubMedID 8546084
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LONG-TERM EFFECTS OF VARYING INTENSITIES AND FORMATS OF PHYSICAL-ACTIVITY ON PARTICIPATION RATES, FITNESS, AND LIPOPROTEINS IN MEN AND WOMEN AGED 50 TO 65 YEARS
CIRCULATION
1995; 91 (10): 2596-2604
Abstract
Although exercise parameters such as intensity and format have been shown to influence exercise participation rates and physiological outcomes in the short term, few data are available evaluating their longer-term effects. The study objective was to determine the 2-year effects of differing intensities and formats of endurance exercise on exercise participation rates, fitness, and plasma HDL cholesterol levels among healthy older adults.Higher-intensity, group-based exercise training; higher-intensity, home-based exercise; and lower-intensity, home-based exercise were compared in a 2-year randomized trial. Participants were 149 men and 120 postmenopausal women 50 to 65 years of age who were sedentary and free of cardiovascular disease. Recruitment was achieved through a random digit-dial community telephone survey and media promotion. All exercise occurred in community settings. For higher-intensity exercise training, three 40-minute endurance training sessions per week were prescribed at 73% to 88% of peak treadmill heart rate. For lower-intensity exercise, five 30-minute endurance training sessions per week were prescribed at 60% to 73% of peak treadmill heart rate. Treadmill exercise performance, lipoprotein levels and other heart disease risk factors, and exercise adherence were evaluated at baseline and across the 2-year period. Treadmill exercise test performance improved for all three training conditions during year 1 and was successfully maintained during year 2, particularly for subjects in the higher-intensity, home-based condition. Subjects in that condition also showed the greatest year 2 exercise adherence rates (P < .003). Although no significant increases in HDL cholesterol were observed during year 1, by the end of year 2 subjects in the two home-based training conditions showed small but significant HDL cholesterol increases over baseline (P < .01). The increases were particularly pronounced for subjects in the lower-intensity condition, whose exercise prescription required more frequent exercise sessions per week. For all exercise conditions, increases in HDL cholesterol were associated with decreases in waist-to-hip ratio in both men and women (P < .04).While older adults can benefit from initiating a regular regimen of moderate-intensity exercise in terms of improved fitness levels and small improvements in HDL cholesterol levels, the time frame needed to achieve HDL cholesterol change (2 years) may be longer than that reported previously for younger populations. Frequency of participation may be particularly important for achieving such changes. Supervised home-based exercise regimens represent a safe, attractive alternative for achieving sustained participation.
View details for Web of Science ID A1995QX58700017
View details for PubMedID 7743622
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RELATIONSHIP BETWEEN HABITUAL PHYSICAL-ACTIVITY AND INSULIN AREA AMONG INDIVIDUALS WITH IMPAIRED GLUCOSE-TOLERANCE - THE SAN-LUIS VALLEY DIABETES STUDY
DIABETES CARE
1995; 18 (4): 490-497
Abstract
To determine whether higher levels of physical activity are associated with lower fasting insulin levels and lower insulin areas under the oral glucose tolerance curve in individuals with impaired glucose tolerance (IGT) in a community setting.Data from a cross-sectional study of a population consisting of 219 Hispanic and non-Hispanic white men and women with IGT (by World Health Organization criteria) in two rural Colorado counties were analyzed. Total physical activity was assessed by a 7-day physical activity recall, from which metabolic equivalents (METs) were estimated (expressed as MET h/week). Relationships of MET h/week with fasting insulin levels and insulin areas were assessed while considering obesity, age, and other risk factors known to influence fasting insulin level and insulin area.Among all subjects, univariate analyses showed that higher physical activity levels were associated with lower mean insulin areas and fasting insulin levels (both P < 0.05). Multiple linear regression showed that higher levels of physical activity were significantly associated with lower values of of the insulin area (P < 0.001) but not with fasting insulin levels. The relationship between insulin area and habitual physical activity was independent of obesity, fat distribution, and age.On the basis of cross-sectional data, we conclude that higher levels of habitual physical activity are associated with lower insulin areas in a population of individuals with IGT. Understanding the impact of physical activity on markers of insulin action in individuals with IGT is important because of the greatly enhanced risk of non-insulin-dependent diabetes mellitus and, hence, cardiovascular disease in this population.
View details for Web of Science ID A1995QQ21600009
View details for PubMedID 7497858
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PHYSICAL-ACTIVITY AND PUBLIC-HEALTH - A RECOMMENDATION FROM THE CENTERS-FOR-DISEASE-CONTROL-AND-PREVENTION AND THE AMERICAN-COLLEGE-OF-SPORTS-MEDICINE
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
1995; 273 (5): 402-407
Abstract
To encourage increased participation in physical activity among Americans of all ages by issuing a public health recommendation on the types and amounts of physical activity needed for health promotion and disease prevention.A planning committee of five scientists was established by the Centers for Disease Control and Prevention and the American College of Sports Medicine to organize a workshop. This committee selected 15 other workshop discussants on the basis of their research expertise in issues related to the health implications of physical activity. Several relevant professional or scientific organizations and federal agencies also were represented.The panel of experts reviewed the pertinent physiological, epidemiologic, and clinical evidence, including primary research articles and recent review articles.Major issues related to physical activity and health were outlined, and selected members of the expert panel drafted sections of the paper from this outline. A draft manuscript was prepared by the planning committee and circulated to the full panel in advance of the 2-day workshop. During the workshop, each section of the manuscript was reviewed by the expert panel. Primary attention was given to achieving group consensus concerning the recommended types and amounts of physical activity. A concise "public health message" was developed to express the recommendations of the panel. During the ensuing months, the consensus statement was further reviewed and revised and was formally endorsed by both the Centers for Disease Control and Prevention and the American College of Sports Medicine.Every US adult should accumulate 30 minutes or more of moderate-intensity physical activity on most, preferably all, days of the week.
View details for Web of Science ID A1995QD20300025
View details for PubMedID 7823386
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EXERCISE STANDARDS - A STATEMENT FOR HEALTH-CARE PROFESSIONALS FROM THE AMERICAN-HEART-ASSOCIATION
CIRCULATION
1995; 91 (2): 580-615
View details for Web of Science ID A1995QB42600053
View details for PubMedID 7805272
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THE ASSOCIATIONS OF HIGH-DENSITY-LIPOPROTEIN SUBCLASSES WITH INSULIN-LEVELS AND GLUCOSE-LEVELS, PHYSICAL-ACTIVITY, RESTING HEART-RATE, AND REGIONAL ADIPOSITY IN MEN WITH CORONARY-ARTERY-DISEASE - THE STANFORD CORONARY RISK INTERVENTION PROJECT BASE-LINE SURVEY
METABOLISM-CLINICAL AND EXPERIMENTAL
1995; 44 (1): 106-114
Abstract
We used nondenaturing polyacrylamide gradient gel electrophoresis to examine the associations of high-density lipoprotein (HDL) subclasses with adiposity, physical activity, resting heart rate (an indicator of sympathetic drive), and plasma insulin and glucose levels in 97 men with angiographically documented coronary artery disease. These men neither smoked nor used medications known to affect lipoproteins. The absorbency of protein stain was used as an index of mass concentrations at intervals of 0.01 nm within five HDL subclasses: HDL3c (7.2 to 7.8 nm), HDL3b (7.8 to 8.2 nm), HDL3a (8.2 to 8.8 nm), HDL2a (8.8 to 9.7 nm), and HDL2b (9.7 to 12 nm). HDL peak diameter was determined from the predominant peak of the HDL particle distribution when plotted against particle diameter. Four men who were non-insulin-dependent diabetics as defined by a fasting glucose exceeding 140 mg/dL had significantly higher plasma HDL3b levels and significantly smaller HDL peak diameters than nondiabetic men, and were therefore excluded from further analyses. In the remaining 93 nondiabetic men, plasma HDL3b levels correlated positively with indices of truncal obesity (waist to hip ratio and subscapular skinfold), whereas plasma HDL2b levels correlated negatively with indices of total adiposity (body mass index [BMI]) and truncal obesity (subscapular and abdominal skinfold). Fasting plasma insulin levels correlated negatively with HDL3a, HDL2a, and HDL2b. Obesity significantly affected the relationships of resting heart rate with insulin and HDL subclasses.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1995QA74100018
View details for PubMedID 7854154
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MUSCLE PATHOLOGY AND CLINICAL MEASURES OF DISABILITY IN CHILDREN WITH CEREBRAL-PALSY
JOURNAL OF ORTHOPAEDIC RESEARCH
1994; 12 (6): 758-768
Abstract
We performed a histologic and morphometric study of spastic muscle from 10 children with diplegic cerebral palsy, comparing muscle structure with the gait parameters of energy expenditure index and dynamic electromyography. Variations in fiber area within and between fiber types were increased significantly in children with cerebral palsy. In each of the control subjects, the combined coefficient of variation for type-1 and type-2 fiber area was less than 25% and the average was 17%; in the subjects with cerebral palsy, the combined coefficient of variation was more than 25% and the average was 36% (p < or = 0.004). The average difference between the mean area of type-1 and type-2 fibers was 26.7 +/- 18.9% for subjects with cerebral palsy and 4.2 +/- 2.4% for control subjects (p < or = 0.004). There was a 67% predominance of one fiber type in the subjects with cerebral palsy compared with a 55% predominance in the control subjects (p < or = 0.03). The difference between the total area of type-1 and type-2 fibers was 57% in the subjects with cerebral palsy and 17% in the control subjects (p < or = 0.002). There was a significant correlation between the combined coefficient of variation of fiber area and the energy expenditure index (r = 0.77, p < or = 0.03). The difference between the mean area of type-1 and type-2 fibers correlated with prolongation of electromyographic activity (r = 0.69, p < or = 0.05). No abnormalities in fiber ultrastructure were found in the subjects with cerebral palsy. Children with cerebral palsy had abnormal variation in the size of muscle fibers and altered distribution of fiber types. The values for variation in fiber area correlated with the energy expenditure index and with prolongation of electromyographic activity during walking.
View details for Web of Science ID A1994PW53900002
View details for PubMedID 7983551
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CLASSIFICATION OF SPORTS
26th Bethesda Conference on Recommendations for Determining Eligibility for Competition in Athletes with Cardiovascular Abnormalities
LIPPINCOTT WILLIAMS & WILKINS. 1994: S242–S245
View details for Web of Science ID A1994PM54800005
View details for PubMedID 7934746
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CLASSIFICATION OF SPORTS
26th Bethesda Conference on Recommendations for Determining Eligibility for Competition in Athletes with Cardiovascular Abnormalities
ELSEVIER SCIENCE INC. 1994: 864–66
View details for Web of Science ID A1994PN84500005
View details for PubMedID 7930217
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THE EFFICACY AND SAFETY OF EXERCISE PROGRAMS IN CARDIAC REHABILITATION
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1994; 26 (7): 815-823
Abstract
Physical activity performed by patients with coronary heart disease is a two-edged sword. A number of biological changes produced by regular exercise may reduce the risk of future cardiac events, while the increase in cardiac work produced by this same exercise can predispose the patient to sudden cardiac death. Data from observational studies as well as randomized clinical trials demonstrate a lower cardiac mortality rate for men participating in exercise rehabilitation programs vs nonparticipants. Overall, exercise program participants appear to experience a reduction of approximately 25% in cardiac and all-cause mortality, but no single study has provided definitive results. During medically supervised exercise, the risk of cardiac death based on reports of programs in the United States is approximately one event in every 60,000 participant-hours of exercise. At this rate, a typical rehabilitation program that has 95 patients exercising 3 h.wk-1 could expect a sudden cardiac death during an exercise session once every 4 yr. No data have been published on the morbidity or mortality benefits or risks of home-based exercise or for women participants. Also, the contribution of continuous electrocardiographic monitoring to the safety of exercise training of cardiac patients is yet to be defined.
View details for Web of Science ID A1994NV49600003
View details for PubMedID 7934753
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Effect of recruitment strategy on types of subjects entered into a primary prevention clinical trial.
Annals of epidemiology
1994; 4 (4): 312-320
Abstract
Clinical trials typically recruit subjects through referrals or media promotion, with generalizability of the results often uncertain. As part of a primary prevention trial to evaluate strategies for increasing physical activity in sedentary men and women, two recruitment sources, a random-digit-dial telephone survey and a community media campaign, were used to identify subjects. Baseline characteristics of 357 randomized men and women aged 50 to 65 years were compared by recruitment source. Whereas there were few differences between recruitment sources for demographic variables, telephone survey recruitment was particularly successful in recruiting smokers and persons with other cardiovascular risk factors into the trial. Counter to expectations, subsequent exercise adherence rates did not differ by recruitment source. The results suggest that the survey method, while more expensive, may be particularly useful for locating higher-risk subjects who could especially benefit from increases in physical activity but who rarely are recruited through more traditional approaches.
View details for PubMedID 7921321
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J.B. Wolffe Memorial Lecture. Health consequences of physical activity: understanding and challenges regarding dose-response.
Medicine and science in sports and exercise
1994; 26 (6): 649-660
Abstract
The Guidelines for Exercise Training initially developed by the American College of Sports Medicine in 1978 and updated in 1990 have served as the foundation for most recommendations regarding physical activity program design for the general public. These guidelines have proven to be very useful by providing a specific regimen for enhancing aerobic capacity and body composition. As data supporting a causal link between increased activity or fitness and health status have evolved, questions have been raised about potential limitations of these guidelines for promoting physical activity to increase the health status of sedentary adults. The major issues have involved the necessity to achieve the values for each of the program parameters, especially the intensity, duration, and frequency of exercise, in order to improve health status. To address these issues, a paradigm shift from exercise training to promote physical fitness to physical activity to promote health has been introduced. This new paradigm is based on the results from numerous studies indicating that a generally active life style is associated with better health and performance and greater longevity and a certain set of assumptions, yet to be fully tested. The following article provides some background leading to the development of the ACSM guidelines and presents some of those issues we understand and some we do not regarding the characteristics of daily physical activity or exercise training that are likely to improve the physical health status of sedentary persons.
View details for PubMedID 8052103
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EFFECTS OF INTENSIVE MULTIPLE RISK FACTOR REDUCTION ON CORONARY ATHEROSCLEROSIS AND CLINICAL CARDIAC EVENTS IN MEN AND WOMEN WITH CORONARY-ARTERY DISEASE - THE STANFORD-CORONARY-RISK-INTERVENTION-PROJECT (SCRIP)
CIRCULATION
1994; 89 (3): 975-990
Abstract
Recent clinical trials have shown that modification of plasma lipoprotein concentrations can favorably alter progression of coronary atherosclerosis, but no data exist on the effects of a comprehensive program of risk reduction involving both changes in lifestyle and medications. This study tested the hypothesis that intensive multiple risk factor reduction over 4 years would significantly reduce the rate of progression of atherosclerosis in the coronary arteries of men and women compared with subjects randomly assigned to the usual care of their physician.Three hundred men (n = 259) and women (n = 41) (mean age, 56 +/- 7.4 years) with angiographically defined coronary atherosclerosis were randomly assigned to usual care (n = 155) or multifactor risk reduction (n = 145). Patients assigned to risk reduction were provided individualized programs involving a low-fat and -cholesterol diet, exercise, weight loss, smoking cessation, and medications to favorably alter lipoprotein profiles. Computer-assisted quantitative coronary arteriography was performed at baseline and after 4 years. The main angiographic outcome was the rate of change in the minimal diameter of diseased segments. All subjects underwent medical and risk factor evaluations at baseline and yearly for 4 years, and reasons for all hospitalizations and deaths were documented. Of the 300 subjects randomized, 274 (91.3%) completed a follow-up arteriogram, and 246 (82%) had comparative measurements of segments with visible disease at baseline and follow-up. Intensive risk reduction resulted in highly significant improvements in various risk factors, including low-density lipoprotein cholesterol and apolipoprotein B (both, 22%), high-density lipoprotein cholesterol (+12%), plasma triglycerides (-20%), body weight (-4%), exercise capacity (+20%), and intake of dietary fat (-24%) and cholesterol (-40%) compared with relatively small changes in the usual-care group. No change was observed in lipoprotein(a) in either group. The risk-reduction group showed a rate of narrowing of diseased coronary artery segments that was 47% less than that for subjects in the usual-care group (change in minimal diameter, -0.024 +/- 0.066 mm/y versus -0.045 +/- 0.073 mm/y; P < .02, two-tailed). Three deaths occurred in each group. There were 25 hospitalizations in the risk-reduction group initiated by clinical cardiac events compared with 44 in the usual-care group (rate ratio, 0.61; P = .05; 95% confidence interval, 0.4 to 0.9).Intensive multifactor risk reduction conducted over 4 years favorably altered the rate of luminal narrowing in coronary arteries of men and women with coronary artery disease and decreased hospitalizations for clinical cardiac events.
View details for Web of Science ID A1994NA76200008
View details for PubMedID 8124838
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Effects of exercise training on plasma lipids and lipoproteins.
Exercise and sport sciences reviews
1994; 22: 477-521
View details for PubMedID 7925552
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METABOLIC AND BEHAVIORAL COVARIATES OF HIGH-DENSITY-LIPOPROTEIN CHOLESTEROL AND TRIGLYCERIDE CONCENTRATIONS IN POSTMENOPAUSAL WOMEN
JOURNAL OF THE AMERICAN GERIATRICS SOCIETY
1993; 41 (12): 1289-1294
Abstract
To determine predictors of high-density lipoprotein cholesterol (HDL) and triglyceride (TG) concentrations in postmenopausal women.Cross-sectional study.Clinical research facility.One hundred twenty-seven healthy, relatively sedentary, postmenopausal women not on estrogen replacement, mean age 57 years.Alcohol intake, cigarette smoking, aerobic fitness (VO2max), body mass index (BMI), percent body fat, waist-hip ratio, lipids and lipoproteins, fasting plasma glucose (FPG), and insulin (FPI) concentrations.In univariate analyses, HDL was significantly (P < 0.05) inversely related to BMI, waist-hip ratio, smoking, FPG, and FPI, and directly related to VO2max and alcohol intake. Triglycerides were related directly to BMI, waist-hip ratio, percent body fat, FPG, and FPI, and inversely to VO2max. In stepwise multiple regressions, BMI, waist-hip ratio, alcohol, smoking, and FPG were significantly associated with HDL (R2 for the model = 0.43). Addition of TG to these models reduced relations of BMI and waist-hip ratio, but not the other variables, to insignificance. For triglycerides, waist-hip ratio, alcohol, smoking, FPG, and FPI were significant predictors (R2 = 0.33). VO2max and percent body fat did not contribute to any model.Obesity, abdominal obesity, smoking, alcohol intake, and measures of carbohydrate metabolism predict HDL and triglyceride concentrations in postmenopausal women.
View details for Web of Science ID A1993MK55900001
View details for PubMedID 8227909
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ENDURANCE EXERCISE AND HEALTH-RELATED QUALITY-OF-LIFE IN 50-65 YEAR-OLD ADULTS
GERONTOLOGIST
1993; 33 (6): 782-789
Abstract
Health-related quality of life was evaluated in relation to endurance exercise over the prior year for 194 previously sedentary, healthy men and women aged 50-65 using a posttest-only design. Three exercise regimens were studied that varied in format (class-based vs home-based) and intensity (higher vs lower). In all regimens, subjects who participated more had better physical health 12 months after program initiation (p values < .05); no differences were observed in general psychological well-being. Extent of participation, rather than format or intensity of exercise, was associated with better physical health in this population.
View details for Web of Science ID A1993ML07100010
View details for PubMedID 8314105
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Physical activity in young black and white women. The CARDIA Study.
Annals of epidemiology
1993; 3 (6): 636-644
Abstract
Total physical activity scores, based on level of participation in 13 types of activities for 2658 black and white women aged 18 to 30 years were examined in relation to demographic, health behavior, psychosocial, and obesity data to compare levels of physical activity and determine reasons for disparities between blacks and whites. Black women had lower scores than white women--geometric mean of 178 (95% confidence interval (CI): 167, 189) versus 318 (95% CI: 305, 332). After controlling for age and education, physical activity was associated with physical activity level before high school, life events score, John Henryism, and competitiveness in both groups. In white women only, it was associated with alcohol intake and need to excel, and negatively associated with number of children, number of cigarettes smoked, and fatness. Race remained a predictor of physical activity after controlling for each variable. Relationships between physical activity and age, education, cigarette smoking, and life events differed significantly by race. Black women had lower physical activity levels than white women, which may contribute to higher rates of obesity and coronary heart disease. Racial differences in physical activity remain largely unexplained by the factors examined.
View details for PubMedID 7921312
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Physical inactivity. Workshop V. AHA Prevention Conference III. Behavior change and compliance: keys to improving cardiovascular health.
Circulation
1993; 88 (3): 1402-1405
View details for PubMedID 8353908
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ASSOCIATIONS BETWEEN CHANGES IN PHYSICAL-ACTIVITY AND RISK-FACTORS FOR CORONARY HEART-DISEASE IN A COMMUNITY-BASED SAMPLE OF MEN AND WOMEN - THE STANFORD 5-CITY PROJECT
AMERICAN JOURNAL OF EPIDEMIOLOGY
1993; 138 (4): 205-216
Abstract
Aerobic exercise training studies involving volunteers generally result in an improved cardiovascular risk factor profile. Little is known, however, about associations between physical activity change and risk factor change in a more representative sample, such as a community. This investigation evaluated correlations between a composite physical activity change score and change in cardiovascular risk factors from 1979 to 1985 in the cohort sample of the Stanford Five-City Project. Men (n = 380) and women (n = 427) between the ages of 18 and 74 years were evaluated for change in self-reported physical activity and change in total cholesterol, high density lipoprotein cholesterol (HDL cholesterol), systolic blood pressure, resting pulse rate, and body mass index (weight (kg)/height (m)2). For men, improvement in the composite physical activity score significantly correlated with an increase in HDL cholesterol (r = 0.14, p = 0.005) and decreases in body mass index (r = -0.16, p = 0.001) and estimated 10-year coronary heart disease risk score (r = -0.10, p = 0.056). For women, improvement in the physical activity score was associated with changes in HDL cholesterol (r = 0.11, p = 0.028) and resting pulse rate (r = -0.15, p = 0.001). These data demonstrate that an increase in physical activity over 5 years is favorably associated with changes in major cardiovascular disease risk factors in men and women and support the public health efficacy of community-wide promotion of physical activity.
View details for Web of Science ID A1993LZ15600001
View details for PubMedID 8356962
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CIGARETTE-SMOKING AND SUBMAXIMAL EXERCISE TEST DURATION IN A BIRACIAL POPULATION OF YOUNG-ADULTS - THE CARDIA STUDY
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1993; 25 (8): 911-916
Abstract
Symptom-limited, graded exercise treadmill testing was performed by 4,968 white and black adults, ages 18-30 yr, during the baseline examination for the Coronary Artery Risk Development in Young Adults (CARDIA) study. Compared with nonsmokers, the mean exercise test duration of smokers was 29-64 s shorter depending on race/gender group (all P < 0.001), but mean duration to heart rate 130 (beats.min-1) ranged from 20-50 s longer (P < 0.05). In each race/gender group, test duration to heart rates up to 150 was 15-35 s longer (P < 0.05) in smokers than in nonsmokers after adjustment for age, sum of skinfolds, hemoglobin, and physical activity score. The mean maximum heart rate was lower in smokers than in nonsmokers (difference ranging from 6.7 beats.min-1 in white men to 11.2 beats.min-1 lower in black women, P < 0.001), although maximum rating of perceived exertion was nearly identical in smokers and nonsmokers. Chronic smoking appears to blunt the heart rate response to exercise, so that exercise duration to submaximal heart rates is increased even though maximal performance is impaired. This may result from downloading of beta-receptors caused by smoking. Smoking status should be considered in the evaluation of physical fitness data utilizing submaximal test protocols, or else the fitness of smokers relative to nonsmokers is likely to be overestimated.
View details for Web of Science ID A1993LR35400004
View details for PubMedID 8371651
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A COMPARISON OF OXYGEN PULSE AND RESPIRATORY EXCHANGE RATIO IN CEREBRAL-PALSIED AND NONDISABLED CHILDREN
ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION
1993; 74 (7): 702-705
Abstract
Energy expended while walking is increased for children with cerebral palsy compared to nondisabled children. This study compared oxygen uptake, oxygen pulse, and the respiratory exchange ratio (RER) in children with cerebral palsy and nondisabled children walking on a treadmill. Resting oxygen uptake and oxygen pulse values were not different in the two groups. At a given walking speed, oxygen uptake, oxygen pulse, and RER were higher for subjects with cerebral palsy. At a given level of submaximal oxygen uptake, oxygen pulse and RER values were not different in subjects with cerebral palsy compared to nondisabled children. It was concluded that the cardiorespiratory response to walking at submaximal level of work is not significantly different for children with cerebral palsy.
View details for Web of Science ID A1993LM07900006
View details for PubMedID 8328890
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EFFECTS OF DIFFERING INTENSITIES AND FORMATS OF 12 MONTHS OF EXERCISE TRAINING ON PSYCHOLOGICAL OUTCOMES IN OLDER ADULTS
HEALTH PSYCHOLOGY
1993; 12 (4): 292-300
Abstract
The 12-month effects of exercise training on psychological outcomes in adults ages 50-65 years were evaluated. Ss (N = 357) were randomly assigned to assessment-only control or to higher intensity group, higher intensity home, or lower intensity home exercise training. Exercisers showed reductions in perceived stress and anxiety in relation to controls (p < .04). Reductions in stress were particularly notable in smokers. Regardless of program assignment, greater exercise participation was significantly related to less anxiety and fewer depressive symptoms, independent of changes in fitness or body weight (p < .05). It was concluded that neither a group format nor vigorous activity was essential in attaining psychological benefits from exercise training in healthy adults.
View details for Web of Science ID A1993NL74100006
View details for PubMedID 8404803
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ASSOCIATION OF LIPOPROTEIN SUBCLASS DISTRIBUTION WITH USE OF SELECTIVE AND NONSELECTIVE BETA-BLOCKER MEDICATIONS IN PATIENTS WITH CORONARY HEART-DISEASE
ATHEROSCLEROSIS
1993; 101 (1): 1-8
Abstract
The relationship of beta-blocker drug use to plasma low density lipoprotein-cholesterol (LDL-C), lipoprotein mass distribution, (LDL, Sf0-12), intermediate density lipoproteins (IDL, Sf12-20), very low density lipoproteins (VLDL, Sf20-400), and high density lipoproteins (HDL, F(1.2)0-9) were examined in 206 men with coronary heart disease. Thirty-three used non-selective (NSEL), 49 used selective (SEL), and were compared to 124 who used no beta-blockade (NoBB). No significant between group differences were seen for potentially confounding variables. LDL and IDL mass, total cholesterol and LDL-cholesterol were not significantly different between groups. HDL-C was significantly lower in both NSEL (P < 0.005) and SEL (P < 0.01). NSEL and SEL had significantly lower HDL mass (P < 0.005 and P < 0.005) and SEL (P < 0.01 and P = 0.06), and HDL3 mass (P < 0.01 and P < 0.05). VLDL mass was significantly higher (P < 0.02) only in NSEL. Small LDL (Sf0-7) was not significantly different between groups and large LDL (Sf7-12) was significantly lower in NSEL (P < 0.05) and SEL (P < 0.05). LDL peak Sf was significantly lower in both NSEL (P < 0.005) and SEL (P < 0.02) compared to NoBB. Despite the lack of differences in levels of LDL-cholesterol, beta-blocker use is associated with a significant difference in the distribution of larger, more buoyant to smaller, more dense LDL particles. Reduced HDL levels in subjects on beta-blockade therapy are associated with reductions in both HDL2 and HDL3 subclasses.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1993LM69600001
View details for PubMedID 8105786
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DAILY PHYSICAL-ACTIVITY LEVELS IN CONGESTIVE-HEART-FAILURE
AMERICAN JOURNAL OF CARDIOLOGY
1993; 71 (11): 921-925
Abstract
To determine the level of daily physical activity routinely performed by patients with congestive heart failure (CHF) and the ability of clinical and laboratory assessments of function to predict peak daily activity levels, 45 patients with CHF were evaluated in the laboratory and during 2 days of usual activity. Subjects performed symptom-limited treadmill exercise tests with respiratory gas analysis and wore a Vitalog activity monitor with continuous measurement of heart rate and body motion. Mean maximal oxygen uptake for this sample was 16.8 ml/kg/min. Peak daily physical activity involved walking on a flat surface (44%), or general activities (housework/yardwork, 42%). Most subjects were asymptomatic (49%) during daily physical activity, 22% noted dyspnea, 16% fatigue and 13% sore muscles/joints. Perceived intensity of peak daily physical activity (mean = 4.19, SD = 2.21) was similar to perceived exertion (mean = 3.73, SD = 1.37) reported at ventilatory threshold measured during treadmill exercise testing. Subjects may control their peak daily physical activity to minimize symptoms experienced. It was further observed that current methods of assessing functional capacity in these patients were inadequate for estimating the peak level of daily activity. In conclusion, daily physical activity levels are low in patients with congestive heart failure and a gap exists between exercise capacity and actual performance of daily physical activity.
View details for Web of Science ID A1993KX26500007
View details for PubMedID 8465782
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CORONARY-ARTERY SIZE AND DILATING CAPACITY IN ULTRADISTANCE RUNNERS
CIRCULATION
1993; 87 (4): 1076-1082
Abstract
Increases in coronary artery size and dilating capacity have been observed in some animals after endurance training, and at autopsy, active men appear to have enlarged epicardial coronary arteries. This cross-sectional study was designed to test the hypothesis that highly trained endurance runners have larger epicardial coronary arteries and greater dilating capacity than inactive men.The subjects, ages 39-66 years, included 11 male volunteers who had participated in ultradistance running during the past 2 years and 11 physically inactive men who had been referred for arteriography but had no visible coronary artery disease. The internal diameter of the proximal segments of each major epicardial coronary artery was measured before and after nitroglycerin administration using a computer-based quantitative arteriographic analysis system. Measurements also included maximal oxygen uptake, plasma lipoprotein concentrations, body composition, and cardiac mass by echocardiography. Before nitroglycerin, the sum of the cross-sectional areas for the proximal right, left anterior descending, and circumflex arteries was not different for the runners and the inactive men: 22.7 +/- 4.79 versus 21.0 +/- 7.97 mm2 (p = 0.57), respectively. However, the increase in the sum of the cross-sectional area for the proximal right, left anterior descending, and circumflex arteries in response to nitroglycerin was greater for the runners (13.20 +/- 4.76 versus 6.00 +/- 3.02 mm2; p = 0.002). Left ventricular mass index (152 +/- 21 versus 116 +/- 41 g/m2; p < 0.05) but not left ventricular mass (284 +/- 40 versus 246 +/- 91 g; p = 0.22) was significantly greater for the runners. Among the runners, dilating capacity was positively correlated with aerobic capacity and negatively related to adiposity, resting heart rate, and plasma lipoprotein concentrations.Highly trained, middle-aged endurance runners demonstrated a significantly greater dilating capacity of their epicardial coronary arteries in response to nitroglycerin compared with inactive men. The causes of this greater dilating capacity and its clinical significance need to be determined.
View details for Web of Science ID A1993KW42200002
View details for PubMedID 8462135
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COMPENDIUM OF PHYSICAL ACTIVITIES - CLASSIFICATION OF ENERGY COSTS OF HUMAN PHYSICAL ACTIVITIES
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1993; 25 (1): 71-80
Abstract
A coding scheme is presented for classifying physical activity by rate of energy expenditure, i.e., by intensity. Energy cost was established by a review of published and unpublished data. This coding scheme employs five digits that classify activity by purpose (i.e., sports, occupation, self-care), the specific type of activity, and its intensity as the ratio of work metabolic rate to resting metabolic rate (METs). Energy expenditure in kilocalories or kilocalories per kilogram body weight can be estimated for all activities, specific activities, or activity types. General use of this coding system would enhance the comparability of results across studies using self reports of physical activity.
View details for Web of Science ID A1993KG53700011
View details for PubMedID 8292105
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SIMULTANEOUS MEASUREMENT OF HEART-RATE AND BODY MOTION TO QUANTITATE PHYSICAL-ACTIVITY
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1993; 25 (1): 109-115
Abstract
None of the various methods used to measure habitual physical activity over days, weeks, or years in the general population have yet proven entirely satisfactory. A major problem is that no "gold standard" exists for the validation of various questionnaires, logs, or diaries that can be used in large sample population studies. Attempts have been made to accurately measure the activity profile by using heart rate or various motion sensors or accelerometers, but each approach has had significant limitations. The availability of new solid state recording techniques and computer-based analytic and display procedures now makes it possible to simultaneously record heart rate and body movement continuously for days and to combine the analysis of these data using customized software. Preliminary evaluation of this concept of simultaneous recording and analysis of heart rate and body motion via movement sensors on an arm and leg were conducted in 19 men. Subjects performed a variety of exercises in the laboratory during which heart rate, leg motion, arm motion, and oxygen uptake were recorded. Various issues regarding the prediction of energy expenditure from heart rate and body movement independently and in combination were evaluated. The results demonstrate that the accuracy of estimating oxygen uptake during a wide range of activities is improved when individualized heart rate--oxygen uptake regressions are used and heart rate and body movement are analyzed simultaneously rather that separately.
View details for Web of Science ID A1993KG53700015
View details for PubMedID 8423743
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EFFECTIVENESS OF LOW-DOSE COLESTIPOL THERAPY IN PATIENTS WITH MODERATE HYPERCHOLESTEROLEMIA
AMERICAN JOURNAL OF CARDIOLOGY
1992; 70 (2): 135-140
Abstract
Recommended doses of bile-acid binding resins have an established hypocholesterolemic effect, but data on responses to low doses, especially in women and subjects with moderate hypercholesterolemia, are sparse. A double-blind, placebo-controlled, randomized trial of 3 low doses of colestipol hydrochloride was conducted in women and men with moderate hypercholesterolemia. Men and women with plasma low-density lipoprotein (LDL) cholesterol concentrations greater than 4 mmol/liter (155 mg/dl) and triglyceride concentrations less than 2.82 mmol/liter (250 mg/dl) were recruited for the study. Eligible patients (54 women and 98 men) were placed on the American Heart Association step I diet 6 weeks before randomization. Participants were subsequently assigned to 1 of 4 drug treatment groups (placebo, and 5, 10 and 15 g/day of colestipol in 2 divided doses) for an additional 12 weeks. Of the 152 patients randomized, 141 completed all aspects of the study. For the treatment groups--placebo, and 5, 10 and 15 g of colestipol--LDL cholesterol reductions (mmol/liter) were observed respectively (n = 141): 0.10 +/- 0.49 (2.7%), 0.65 +/- 0.41 (16.3%), 0.98 +/- 0.36 (22.8%) and 1.17 +/- 0.47 (27.2%) (p less than 0.001). Similar changes were observed in total cholesterol and apolipoprotein B concentrations. The apolipoprotein B/LDL cholesterol ratio increased significantly with increasing colestipol dosage. Modest but insignificant changes in plasma triglyceride levels occurred, and high-density lipoprotein cholesterol levels remained unchanged. A dose of 5 g/day of colestipol achieved 51% of the LDL cholesterol reduction noted with 15 g/day. Low-dose colestipol therapy is effective in the treatment of patients with moderate hypercholesterolemia.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1992JD35500001
View details for PubMedID 1626496
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CARDIOVASCULAR BENEFITS AND ASSESSMENT OF PHYSICAL-ACTIVITY AND PHYSICAL-FITNESS IN ADULTS
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1992; 24 (6): S201-S220
View details for PubMedID 1625547
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WAIST HIP RATIO, BODY-MASS INDEX AND PREMATURE CARDIOVASCULAR-DISEASE MORTALITY IN UNITED-STATES-ARMY VETERANS DURING A 23-YEAR FOLLOW-UP-STUDY
INTERNATIONAL JOURNAL OF OBESITY
1992; 16 (6): 417-423
Abstract
A retrospective longitudinal analysis of fat distribution and cause-specific mortality was performed on data from 105,062 men discharged from the United States Army in 1946-47. Baseline height, weight, waist and hip girth, and 23-year follow-up mortality data were available for 84,910 white men. Proportional hazard survival analysis was performed by 5-year age group for waist/hip ratio (WHR) and for body mass index (BMI) in prediction of time to death from ischaemic heart disease (IHD) and stroke. Relative risk of IHD fatality per standard deviation (s.d.) of WHR ranged from 1.11 to 1.17, the higher values appearing in younger age groups. Relative risk due to BMI was not significant in the group aged 16-20 years at time of discharge from service, but ranged from 1.22 to 1.25 per s.d. among the 21-30 year olds. WHR was predictive of cerebrovascular disease mortality among 16-25 year olds, carrying a relative risk of 1.24 to 1.35 per s.d. BMI was not predictive of cerebrovascular disease mortality in any age group. Multivariate models indicated that WHR and BMI were related to subsequent IHD independently of each other in most age groups. WHR and BMI both contribute to risk of premature IHD mortality and WHR to risk of cerebrovascular disease mortality in an initially relatively healthy population of young men, although the effects are not equivalent in all age groups.
View details for Web of Science ID A1992HZ43100002
View details for PubMedID 1322867
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ROLE OF WATER-SOLUBLE DIETARY FIBER IN THE MANAGEMENT OF ELEVATED PLASMA-CHOLESTEROL IN HEALTHY-SUBJECTS
AMERICAN JOURNAL OF CARDIOLOGY
1992; 69 (5): 433-439
Abstract
Guidelines for the use of water-soluble dietary fibers (WSDF) in the dietary management of elevated plasma cholesterol are not well-established. Consequently, 4 studies were conducted to explore the plasma lipid-lowering effects of a variety of WSDF. Studies were randomized, double-blind, placebo-controlled trials involving healthy men and women (plasma cholesterol greater than 5.17 mmol/liter; greater than 200 mg/dl). Study duration ranged from 4 to 12 weeks. The WSDF acacia gum yields a low viscosity, palatable beverage when mixed in water. However, despite its WSDF classification, acacia gum consumed for 4 weeks as the sole WSDF source (15 g of WSDF/day) or primary source in a WSDF mixture (17.2 g of WSDF/day; 56% derived from acacia gum) did not produce a significant lipid-lowering effect versus placebo. When 15 g of WSDF/day consisting of psyllium hust, pectin, and guar and locust bean gums (medium viscosity) was consumed for 4 weeks, significant reductions in cholesterol resulted (total cholesterol 8.3%, low-density lipoprotein cholesterol 12.4%; p less than 0.001) that were comparable to changes achieved with 10 g of WSDF/day from high-viscosity guar gum. The magnitude of the lipid-lowering effect was related to intake of WSDF ranging from 5 to 15 g/day (low-density lipoprotein cholesterol +0.8% [placebo], -5.6% [5 g/day], -6.8% [10 g/day], -14.9% [15 g/day]; p less than 0.01 for trend). The effects of WSDF on plasma lipids were similar for men and women. A diet rich in selected WSDF may be a useful adjunct to the dietary management of elevated plasma cholesterol.
View details for Web of Science ID A1992HD94300001
View details for PubMedID 1310566
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SYMPTOM-LIMITED GRADED TREADMILL EXERCISE TESTING IN YOUNG-ADULTS IN THE CARDIA STUDY
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1992; 24 (2): 177-183
Abstract
Symptom-limited, graded exercise treadmill testing was performed by 4,968 white and black adults, ages 18-30 yr, during the baseline examination for the CARDIA study. The mean estimated maximal exercise capacity by race/gender, expressed as metabolic units (METS), was: white men 13.8, black men 13.0, white women 11.1, and black women 9.4. Exercise test duration was higher in nonsmokers, positively related to physical activity score and pulmonary function (FEV1.ht-2), and inversely related to body mass index. Men had higher mean values than women for both test duration and a measure of submaximal performance, the workload 130 (WL130, the exercise test duration to a heart rate of 130 beats.min-1). Adjusted for age and education, white men had a longer mean test duration than black men (53 s longer, P less than 0.001), but nearly equal mean WL130. White women had higher mean values than black women for both test duration (114 s longer, P less than 0.001) and WL130 (36 s longer, P less than 0.001). Men had higher mean values than women for both outcome measures (P less than 0.001). Thus, in young adults significant gender and ethnic differences exist for exercise test performance, part of which can be explained by personal habits or traits.
View details for Web of Science ID A1992HC81900005
View details for PubMedID 1549006
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PREVALENCE OF SELF-REPORTED POOR SLEEP IN A HEALTHY POPULATION AGED 50-65
SOCIAL SCIENCE & MEDICINE
1992; 34 (1): 49-55
Abstract
Many population-based surveys have reported that the prevalence of poor sleep increases with age. Despite the uniformity of findings, it remains unclear to what extent age-related declines in overall physical health are related to those results. One approach to this problem has been to adjust for such confounding variables multivariately. Some prior studies using this approach have not shown the expected age-related increases in the prevalence of poor sleep. Another approach has been the study of sleep in carefully screened, healthy populations. The current study reports the prevalence of disturbed sleep in a population, ages 50-65, carefully screened for physical health as part of an ongoing study of exercise and cardiovascular function. The prevalence of self-reported trouble falling asleep every night or almost every night (1.1% M, 2.6% F), trouble awakening and returning back to sleep (4.4% M, 3.3% F), and use of hypnotic medication at least twice a week (1.6% M, 2.6% F) were consistently lower than in nearly all previous population-based studies of individuals of comparable age. This implies that when overall physical health factors are taken into account a decline in sleep quality is not necessarily an inevitable component of aging per se. As has been shown in other studies, there were small but statistically significant relationships between self-reported depression and poor sleep. Despite the low prevalence of poor sleep, about a third of the population reported feeling not well-rested and/or not getting the sleep they required. The individuals in this study also reported obtaining significantly less sleep relative to normative data from 30 years ago.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1992GY69500007
View details for PubMedID 1738856
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EFFECT OF A 6-MONTH AEROBIC EXERCISE TRAINING-PROGRAM ON CARDIOVASCULAR RESPONSIVITY IN HEALTHY MIDDLE-AGED ADULTS
JOURNAL OF PSYCHOSOMATIC RESEARCH
1992; 36 (1): 25-36
Abstract
The purpose of this study was to determine the effects of a six month aerobic exercise training regimen on cardiovascular responsivity to mental arithmetic in healthy middle-aged men and women. Subjects were randomly assigned to a moderate intensity exercise intervention or to an assessment-only control group. Before and after the intervention subjects' heart rates and blood pressures were measured doing a mental arithmetic task (N = 83). Other physiological and psychosocial measures included the Type A structured interview and a maximal exercise treadmill test. Validated adherence to the exercise regimen exceeded 75% and there were significant increases in aerobic capacity in those subjects receiving exercise training. Exercise did not significantly reduce cardiovascular responsivity to the stress task. Type A behavior did not interact with reactivity across exercisers or controls nor was it significantly correlated with adherence. The results are discussed with respect to factors that have been previously reported to potentially influence the exercise/reactivity relationship.
View details for Web of Science ID A1992HB79200003
View details for PubMedID 1538348
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RELATION OF FASTING PLASMA-INSULIN CONCENTRATION TO HIGH-DENSITY-LIPOPROTEIN CHOLESTEROL AND TRIGLYCERIDE CONCENTRATIONS IN MEN
ARTERIOSCLEROSIS AND THROMBOSIS
1991; 11 (6): 1636-1642
Abstract
Low plasma high density lipoprotein (HDL) cholesterol concentration is a risk factor for coronary heart disease (CHD) and is frequently associated with high triglyceride concentration. Both of these abnormalities have been related to insulin resistance as estimated by plasma insulin concentrations and to measures of obesity, regional adiposity, and physical fitness. To determine which of these variables (fasting plasma insulin, obesity as measured by body mass index [BMI], or regional adiposity as measured by waist to hip ratio [WHR]) best identifies men with low HDL cholesterol and high triglyceride concentrations, we divided 83 men, aged 50-65 years, who were free of CHD or diabetes, into tertiles based on BMI, WHR, or fasting plasma insulin concentration. Only for plasma insulin tertiles were there statistically significant differences in HDL cholesterol (tertile 1, mean +/- SEM, 1.34 +/- 0.08 mmol/l; 2, 1.16 +/- 0.05 mmol/l; 3, 1.10 +/- 0.06 mmol/l; p less than 0.03) and triglyceride (tertile 1, 1.05 +/- 0.08 mmol/l; 2, 1.48 +/- 0.12 mmol/l; 3, 1.82 +/- 0.17 mmol/l; p less than 0.005) concentrations. In forward stepwise regressions with HDL cholesterol and triglyceride as dependent variables, fasting insulin concentration but not BMI, WHR, or maximal oxygen uptake (VO2max), a measure of physical fitness, predicted HDL cholesterol (R2 = 0.07, p less than 0.02) and triglyceride (R2 = 0.20, p less than 0.001) concentrations. The data suggest that plasma insulin concentration is an important predictor of HDL cholesterol and triglyceride concentrations independent of BMI, WHR, or VO2max.
View details for Web of Science ID A1991GQ63000002
View details for PubMedID 1931867
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RELATIONSHIP BETWEEN HABITUAL PHYSICAL-ACTIVITY AND INSULIN LEVELS AMONG NONDIABETIC MEN AND WOMEN - SAN-LUIS VALLEY DIABETES STUDY
DIABETES CARE
1991; 14 (11): 1066-1074
Abstract
To determine whether higher levels of physical activity would be associated with lower fasting insulin and C-peptide levels in a free-living nondiabetic population.A cross-sectional study was conducted with a Hispanic and non-Hispanic white population of 442 men and 489 women with normal glucose tolerance (by World Health Organization criteria) in two rural Colorado counties. Total physical activity was assessed by a 7-day physical activity recall from which metabolic equivalents were estimated. Relationships between metabolic equivalents and fasting insulin and C-peptide were assessed while considering obesity, age, and other risk factors known to influence fasting insulin levels.Among all subjects, univariate analyses showed that higher activity levels were associated with lower mean fasting insulin and C-peptide levels (P less than or equal to 0.05). Multiple linear regression showed that higher activity was significantly associated with lower values of log fasting insulin and C-peptide levels in men only (P less than 0.001) independent of obesity, fat distribution, and age. Men in the highest tertile of activity had an adjusted mean fasting insulin level of 59.2 pM and fasting C-peptide level of 0.5 nM compared with a fasting insulin level of 72.7 pM and fasting C-peptide level of 0.6 mM for men in the lowest tertile of activity. The magnitude of the inverse association between activity and insulin was greatest in older rather than younger men. Physical activity was not associated with fasting insulin or C-peptide levels in women in the multivariate analyses.Based on cross-sectional data, we conclude that higher levels of habitual physical activity are associated with lower fasting insulin and C-peptide levels in Hispanic and non-Hispanic white men.
View details for Web of Science ID A1991GM85200020
View details for PubMedID 1797488
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SATURATED FAT INTAKE AND INSULIN RESISTANCE IN MEN WITH CORONARY-ARTERY DISEASE
CIRCULATION
1991; 84 (5): 2020-2027
Abstract
To determine whether there is an association between diet and plasma insulin concentration that is independent of obesity, we studied the relation of dietary composition and caloric intake to obesity and plasma insulin concentrations in 215 nondiabetic men aged 32-74 years with angiographically proven coronary artery disease.After adjusting for age, the intake of saturated fatty acids and cholesterol were positively correlated (p less than 0.05) with body mass index (r = 0.18, r = 0.16), waist-to-hip circumference ratio (r = 0.21, r = 0.22), and fasting insulin (r = 0.26, r = 0.23). Carbohydrate intake was negatively correlated with body mass index (r = -0.21), waist-to-hip ratio (r = -0.21), and fasting insulin (r = -0.16). Intake of monounsaturated fatty acids did not correlate significantly with body mass index or waist-to-hip circumference ratio but did correlate positively with fasting insulin (r = 0.24). Intake of dietary calories was negatively correlated with body mass index (r = -0.15). In multivariate analysis, intake of saturated fatty acids was significantly related to elevated fasting insulin concentration independently of body mass index.These cross-sectional findings in nondiabetic men with coronary artery disease suggest that increased consumption of saturated fatty acids is associated independently with higher fasting insulin concentrations.
View details for Web of Science ID A1991GN52200015
View details for PubMedID 1934376
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GROUP-BASED VS HOME-BASED EXERCISE TRAINING IN HEALTHY OLDER MEN AND WOMEN - A COMMUNITY-BASED CLINICAL-TRIAL
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
1991; 266 (11): 1535-1542
Abstract
--To determine the effectiveness of group- vs home-based exercise training of higher and lower intensities among healthy, sedentary older adults.--Year-long randomized, controlled trial comparing (1) higher-intensity group-based exercise training; (2) higher-intensity home-based exercise training; (3) lower-intensity home-based exercise training; or (4) assessment-only control.--General community located in northern California.--One hundred sixty women and 197 men 50 to 65 years of age who were sedentary and free of cardiovascular disease. One out of nine persons contacted through a community random-digit-dial telephone survey and citywide promotion were randomized.--For higher-intensity exercise training, three 40-minute endurance training sessions per week were prescribed at 73% to 88% of peak treadmill heart rate. For lower-intensity exercise training, five 30-minute endurance training sessions per week were prescribed at 60% to 73% of peak treadmill heart rate.--Treadmill exercise test performance, exercise participation rates, and heart disease risk factors.--Compared with controls, subjects in all three exercise training conditions showed significant improvements in treadmill exercise test performance at 6 and 12 months (P less than .03). Lower-intensity exercise training achieved changes comparable with those of higher-intensity exercise training. Twelve-month exercise adherence rates were better for the two home-based exercise training conditions relative to the group-based exercise training condition (P less than .0005). There were no significant training-induced changes in lipid levels, weight, or blood pressure.--We conclude that (1) this community-based exercise training program improved fitness but not heart disease risk factors among sedentary, healthy older adults; (2) home-based exercise was as effective as group exercise in producing these changes; (3) lower-intensity exercise training was as effective as higher-intensity exercise training in the home setting; and (4) the exercise programs were relatively safe.
View details for Web of Science ID A1991GE45800034
View details for PubMedID 1880885
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THE ENERGY-EXPENDITURE INDEX - A METHOD TO QUANTITATE AND COMPARE WALKING ENERGY-EXPENDITURE FOR CHILDREN AND ADOLESCENTS
JOURNAL OF PEDIATRIC ORTHOPAEDICS
1991; 11 (5): 571-578
Abstract
We used heart rate and walking speed to calculate an energy expenditure index (EEI), the ratio of heart rate per meter walked, for 102 normal subjects, age 6-18 years. Heart rate was measured at self-selected slow, comfortable, and fast walking speeds on the floor and on a motor-driven treadmill. At slow walking speeds (37 +/- 10 m/min) the EEI was elevated (0.71 +/- 0.32 beats/m), indicating poor economy. At comfortable speeds (70 +/- 11 m/min) the EEI values decreased to the maximum economy (0.47 +/- 0.13 beats/m). At fast speeds (101 +/- 13 m/min), the EEI increased (0.61 +/- 0.17 beats/m), indicating poor economy relative to comfortable speeds. A graph of the EEI versus walking speed provides a way to evaluate and compare energy expenditure in a clinical setting.
View details for PubMedID 1918341
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THE EFFECTS ON PLASMA-LIPOPROTEINS OF A PRUDENT WEIGHT-REDUCING DIET, WITH OR WITHOUT EXERCISE, IN OVERWEIGHT MEN AND WOMEN
NEW ENGLAND JOURNAL OF MEDICINE
1991; 325 (7): 461-466
Abstract
The National Cholesterol Education Program (NCEP) recommends a low-saturated-fat, low-cholesterol diet, with weight loss if indicated, to correct elevated plasma cholesterol levels. Weight loss accomplished by simple caloric restriction or increased exercise typically increases the level of high-density lipoprotein (HDL) cholesterol. Little is known about the effects on plasma lipoproteins of a hypocaloric NCEP diet with or without exercise in overweight people.We tested the hypothesis that exercise (walking or jogging) will increase HDL cholesterol levels in moderately overweight, sedentary people who adopt a hypocaloric NCEP diet. We randomly assigned 132 men and 132 women 25 to 49 years old to one of three groups: control, hypocaloric NCEP diet, or hypocaloric NCEP diet with exercise. One hundred nineteen of the men and 112 of the women returned for testing after one year.After one year, the subjects in both intervention groups had reached or closely approached NCEP Step 1 dietary goals and reduced their mean body fat significantly (range of reduction in mean fat weight, 4.0 to 7.8 kg). Weight loss on the NCEP diet alone did not significantly change HDL cholesterol levels in either the men or the women as compared with the subjects in the control group. Plasma levels of HDL cholesterol increased significantly more in the men who exercised and dieted (mean [+/- SE] change, +13 +/- 3 percent) than in the men who only dieted (+2 +/- 3 percent, P less than 0.01) or the men who acted as controls (-4 +/- 2 percent, P less than 0.001). HDL cholesterol levels remained about the same in the women who exercised and dieted (+1 +/- 2 percent); they were higher than in the women who only dieted (-10 +/- 3 percent, P less than 0.01), but not higher than in the controls (-3 +/- 3 percent).Regular exercise in overweight men and women enhances the improvement in plasma lipoprotein levels that results from the adoption of a low-saturated-fat, low-cholesterol diet.
View details for Web of Science ID A1991GA76300003
View details for PubMedID 1852180
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CONTRIBUTIONS OF REGIONAL ADIPOSE-TISSUE DEPOTS TO PLASMA-LIPOPROTEIN CONCENTRATIONS IN OVERWEIGHT MEN AND WOMEN - POSSIBLE PROTECTIVE EFFECTS OF THIGH FAT
METABOLISM-CLINICAL AND EXPERIMENTAL
1991; 40 (7): 733-740
Abstract
Anthropometry and dual-photon absorptiometry (DPA) were used to examine associations of regional adiposity with plasma lipid, lipoprotein, and lipoprotein subfraction mass concentrations in moderately overweight men and women. Among 130 women, waist to thigh girth ratio (WTR) correlated with triglycerides (TG) (r = .33, P less than .0001) and negatively with high-density lipoprotein (HDL)-cholesterol (HDL-C) (r = -.37, P less than .0001) concentration, as expected. While WTR did not correlate with low-density lipoprotein (LDL)-cholesterol (LDL-C) it correlated positively with the mass subfraction of small (Sfo, 0 to 7) LDL (r = .38, P less than .0001), and negatively with large (Sfo, 7 to 12) LDL (r = -.31, P less than .01). Among 133 men, similar though weaker relationships were found. Thigh girth correlated positively with HDL and HDL2-C and mass, and with LDL particle size among women. Multivariate analysis suggests that association of WTR with lipoprotein values known to carry risk of coronary heart disease (CHD) are due at least as much to effects of thigh girth as to deleterious effects of waist girth. Estimates of fat weight in thigh and abdominal regions by DPA support thigh fat as contributing to these effects of thigh girth. Thigh fat may contribute to lipoprotein profiles that predict lower risk of cardiovascular disease.
View details for Web of Science ID A1991FV09000014
View details for PubMedID 1870428
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THE ROLE OF INSULIN AND BODY-FAT IN ASSOCIATIONS OF PHYSICAL-ACTIVITY WITH LIPIDS AND LIPOPROTEINS IN A BIETHNIC POPULATION - THE SAN-LUIS-VALLEY DIABETES STUDY
ARTERIOSCLEROSIS AND THROMBOSIS
1991; 11 (4): 973-984
Abstract
It has been postulated that the positive effects of physical activity on high density lipoprotein cholesterol (HDL-C) and HDL-C subfraction 2 (HDL-C2) are mediated through insulin action because increased activity lowers insulin levels and lower insulin levels are associated with higher HDL-C. These relations were evaluated in a rural population of Hispanic and non-Hispanic white (NHW) adults in Colorado. Included were 138 men and 152 women with normal glucose tolerance confirmed by World Health Organization criteria. Total physical activity was assessed by 7-day recall interviews. No significant associations were observed among women. Among men, activity was inversely associated with fasting insulin (r = -0.17, p less than 0.05). From analysis of covariance models including the interaction term activity x ethnicity, total HDL-C was 43.4 mg/dl (95% confidence interval [CI] = 39.1, 47.7) in the low tertile of activity and 50.4 mg/dl (95% CI = 46.3, 54.5) in the high tertile for NHW men, after adjustment for fasting insulin, fasting glucose, body mass index (BMI), waist to hip ratio (WHR), and age. For Hispanic men, adjusted HDL-C was 43.4 mg/dl (95% CI = 38.6, 48.2) and 49.1 mg/dl (95% CI = 44.0, 54.2) in the low and high tertiles, respectively. Adjusted HDL-C2 levels were 52% higher in the most compared with the least active NHW men, whereas there was no difference by activity for Hispanic men. Higher adjusted mean levels of HDL-C3 were observed for the high compared with the low activity tertile in both ethnic groups. Ethnicity-specific models showed that for NHW men, activity explained 12% (p = 0.01), fasting insulin explained 5% (p = 0.05), and BMI explained 6% (p = 0.04) of the variability in total HDL-C, after adjustment for fasting glucose, WHR, and age. These models confirmed that effects of insulin and body fat did not explain the observed associations between activity and total HDL-C and its subfractions.
View details for Web of Science ID A1991FX24800022
View details for PubMedID 2065048
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COMPARISON OF 2 METHODS OF ASSESSING PHYSICAL-ACTIVITY IN THE CORONARY-ARTERY RISK DEVELOPMENT IN YOUNG-ADULTS (CARDIA) STUDY
AMERICAN JOURNAL OF EPIDEMIOLOGY
1991; 133 (12): 1231-1245
Abstract
Physical activity was assessed by questionnaire among 4,956 young blacks and whites aged 18-30 years at the baseline examination (1985-1986) of the Coronary Artery Risk Development in Young Adults (CARDIA) study, a longitudinal study of cardiovascular risk factors. The Physical Activity Recall questionnaire categorized all activity during the previous week, while the Physical Activity History questionnaire quantified participation in 13 specific activities during the previous year. This report compares the two questionnaires with regard to their characterization of the activity levels of the sociodemographic subgroups of the study population and their associations with known physiologic correlates of physical activity. Both questionnaires resulted in the same physical activity patterns for sex (men greater than women) and age (younger greater than older) strata. However, the mean Physical Activity History score was higher in white women than in black women, while the Physical Activity Recall scores were nearly equal. The Physical Activity History score was directly related to educational status, and the Physical Activity Recall score was inversely related to educational status. The Physical Activity History score was generally more strongly associated with physiologic variables known to be related to physical activity (e.g., treadmill test duration). Based upon these findings, which may only be appropriate in this age group, it was concluded that the Physical Activity History score was the more valid measure of habitual physical activity in this study group of young adults.
View details for Web of Science ID A1991FV26600004
View details for PubMedID 2063831
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PHYSICAL-ACTIVITY-ASSESSMENT MEASURES COMPARED IN A BIETHNIC RURAL-POPULATION - THE SAN LUIS VALLEY DIABETES STUDY
AMERICAN JOURNAL OF CLINICAL NUTRITION
1991; 53 (4): 812-820
Abstract
We evaluated the consistency of three questionnaire methods of assessing work and leisure activity in the rural biethnic population of the San Luis Valley Diabetes Study. A 7-d physical activity recall (PAR), a ranking of usual activity, and a history of usual participation in vigorous activity were used. Energy expenditure (kJ.kg-1.wk-1) (EE) was estimated from PAR. Subjects were 503 adults [49% non-Hispanic white (NHW), 51% Hispanic]. Physical activity at work rather than leisure-time activity largely determined total energy expenditure. Average EE at work increased with work rank for all subjects combined [mean EE (SEE) for rank 1 (low) = 324.2 (24.4), rank 4 (high) = 874.0 (102.1)] and within sex, ethnic, and occupational subgroups. Leisure EE increased with leisure rank only for NHW men and employed women. Similar patterns were observed in comparisons of PAR data with history of vigorous activity. Further development and validation of instruments appropriate for use across population subgroups are needed.
View details for Web of Science ID A1991FE15300002
View details for PubMedID 2008858
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THE EFFECT OF APOLIPOPROTEIN-E ISOFORM DIFFERENCE ON POSTPRANDIAL LIPOPROTEIN COMPOSITION IN PATIENTS MATCHED FOR TRIGLYCERIDES, LDL-CHOLESTEROL, AND HDL-CHOLESTEROL
ARTERY
1991; 18 (6): 315-325
Abstract
The postprandial response to three test meals provided during a single day was investigated in subjects with either the apo E3/3 phenotype (n = 8), or the apo E4/3 phenotype (n = 4), who had LDL-C greater than 160 mg/dl. Vitamin A (60,000 U/m2) was ingested with the first meal and retinyl palmitate determined four hours later. Triglyceride and total cholesterol concentration were determined on whole plasma and total cholesterol and free cholesterol determined following single spin ultracentrifugation (d less than 1.006 g/ml) and dextran precipitation of the d greater than 1.006 fraction to separate apoprotein-B containing lipoproteins. Fasting values revealed significantly lower HDL-cholesterol ester (p less than 0.03) and HDL3-cholesterol ester (p less than 0.03) and significantly greater HDL-free cholesterol (p less than 0.03) and HDL3-free cholesterol (p less than 0.02) in subjects with the E4/3 phenotype. Four hour postprandial HDL and HDL3 cholesterol ester increased significantly more (p less than 0.05) in E4/3 patients and HDL and HDL3 free cholesterol decreased significantly more (p less than 0.05) in E4/3 subjects. Eight-hour postprandial change values maintained the significant HDL3-cholesterol ester and free cholesterol difference, and, revealed a significantly greater triglyceride rich lipoprotein cholesterol ester reduction (p less than 0.01) in the E4/3 group. Individuals with the apolipoprotein E4/3 phenotype reveal significant differences in postprandial lipemia compared to individuals with the E3/3 phenotype, and, postprandial lipemia following multiple meals reveals differences not apparent from responses to a single meal.
View details for Web of Science ID A1991GJ10500003
View details for PubMedID 1750804
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EXERCISE STANDARDS - A STATEMENT FOR HEALTH-PROFESSIONALS FROM THE AMERICAN-HEART-ASSOCIATION
CIRCULATION
1990; 82 (6): 2286-2322
View details for Web of Science ID A1990EL84100058
View details for PubMedID 2242557
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LIPOPROTEIN AND HEPATIC LIPASE ACTIVITY AND HIGH-DENSITY-LIPOPROTEIN SUBCLASSES AFTER CARDIAC TRANSPLANTATION
AMERICAN JOURNAL OF CARDIOLOGY
1990; 66 (15): 1131-1134
Abstract
Atherosclerosis is the leading obstacle to long-term survival in cardiac transplant patients. Increases in plasma triglycerides and lipoprotein cholesterol levels occur after transplantation that may contribute to transplant atherosclerosis. The etiology of this increase is unclear. We investigated the interaction of immunosuppressive medications with plasma triglycerides, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, the HDL subclasses HDL2 and HDL3 cholesterol, and hepatic and lipoprotein lipase activity in 72 consecutive cardiac transplant patients compared to 51 healthy control subjects. In the transplantation group, greater concentrations of plasma triglyceride (80%, p less than 0.001), LDL cholesterol (16%, p less than 0.005) and hepatic lipase activity (100%, p less than 0.001) were noted, whereas lipoprotein lipase activity was noted to be significantly lower (124%, p less than 0.001). No difference was detected in HDL, HDL2, or HDL3 cholesterol. Cyclosporine dose was significantly associated with hepatic lipase activity (r = 0.33, p less than 0.02) and inversely associated with lipoprotein lipase activity (r = -0.28, p less than 0.05). Lipoprotein lipase activity after transplantation correlated inversely with triglycerides (r = -0.36, p less than 0.002) and positively with HDL cholesterol (r = 0.23, p less than 0.05) and HDL2 cholesterol (r = 0.29, p less than 0.05). Hepatic lipase activity correlated inversely with LDL cholesterol (r = -0.21, p less than 0.08). In multiple regression analysis, cyclosporine dose was the major source of variation in hepatic lipase activity.
View details for Web of Science ID A1990EF57000019
View details for PubMedID 2220641
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EFFECT OF LONG-TERM COMMUNITY-HEALTH EDUCATION ON BLOOD-PRESSURE AND HYPERTENSION CONTROL - THE STANFORD 5-CITY PROJECT
AMERICAN JOURNAL OF EPIDEMIOLOGY
1990; 132 (4): 629-646
Abstract
The Stanford Five-City Project was initiated in 1978 to evaluate the effects of a community-wide health education program on cardiovascular risk factors, including blood pressure. Two treatment cities received an education program, which used the mass media, various community-based programs, and health professionals, designed to encourage individuals to learn their blood pressure levels, stay in the care of a physician if hypertensive, achieve ideal weight, exercise regularly, and reduce dietary sodium. Physicians were encouraged to follow national hypertension treatment guidelines and were provided with a range of patient education materials. To evaluate the effect of the intervention on cardiovascular risk factors, four independent cross-sectional surveys of randomly selected households and four repeated surveys of a cohort were conducted in both treatment cities and in two of the three control cities. After 5-1/3 years of intervention, blood pressure in the treatment cities exhibited an overall decline of 7.4 and 5.5 mmHg systolic and 5.0 and 3.7 mmHg diastolic in the cohort and independent surveys, respectively. These declines produced net changes between the treatment and control cities ranging from -1.1 to -3.8 mmHg. While the magnitude of these changes is not large, the results are significant from a public health perspective because they reflect changes in the overall community.
View details for Web of Science ID A1990EB31400004
View details for PubMedID 2403104
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IDENTIFYING STRATEGIES FOR INCREASING EMPLOYEE PHYSICAL-ACTIVITY LEVELS - FINDINGS FROM THE STANFORD LOCKHEED EXERCISE SURVEY
HEALTH EDUCATION QUARTERLY
1990; 17 (3): 269-285
Abstract
While worksite exercise programs offer a number of potential advantages with respect to increasing physical activity levels in American adults, typical participation rates remain relatively low. The purpose of this study was to explore employee preferences and needs related to physical activity programming in a major work setting in northern California. Two-thirds (399) of a randomly selected sample of employees responded to a mailed survey. Male and female employees reporting no regular aerobic activity over the past two years more strongly endorsed a number of erroneous beliefs concerning exercise, reported less support for engaging in exercise both at home and at work, and avoided even routine types of activity to a greater extent than more active individuals (p values less than 0.001). Current exercisers reported use of a greater number and variety of motivational strategies as part of their exercise program than past exercisers who were not currently active (p less than 0.001). Respondents, regardless of exercise status and age, reported preferences for moderate-intensity activity occurring away from the workplace which could be performed on one's own rather than in a group or class. Implications of the findings with respect to development of educational and behavioral programs for the current employee population are discussed.
View details for Web of Science ID A1990DX06600004
View details for PubMedID 2228630
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ARE WOMEN USING POSTMENOPAUSAL ESTROGENS - A COMMUNITY SURVEY
AMERICAN JOURNAL OF PUBLIC HEALTH
1990; 80 (10): 1266-1268
Abstract
Self-reported estrogen and progestin use in a California community was determined in 1986-87 from a telephone survey of postmenopausal women (n = 954) ages 50-65 years. Current use of hormones was reported by 32 percent; 26 percent took estrogens alone while 6 percent used estrogen + progestin. Comparisons pointed to significant social network and medical care utilization differences. Women who used estrogen therapy were younger, thinner, lived in smaller household units, and were less likely to be widowed.
View details for Web of Science ID A1990EA29100025
View details for PubMedID 2400044
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SMOKING IN OLDER WOMEN - IS BEING FEMALE A RISK FACTOR FOR CONTINUED CIGARETTE USE
ARCHIVES OF INTERNAL MEDICINE
1990; 150 (9): 1841-1846
Abstract
Current national data indicate that a greater percentage of women entering their fifth and sixth decades of life are current, as opposed to former, smokers, while for men the opposite pattern is present. A representative sample of 1876 men and women aged 50 to 65 years living in a northern California community were interviewed to examine factors related to gender differences in quit rates in this age group. In this well-educated community, a significantly greater percentage of women (25.6%) continued to smoke relative to men (18.6%), with a greater percentage of men reporting being former smokers. Multivariate analysis revealed educational level and marital status, rather than gender, to be significant, Independent factors associated both with current cigarette use and with successful quitting. Our data indicate that it is not being female per se, but rather the disparities in educational level and marital status that are linked with being an older woman, that are associated with continued smoking in this age group. In light of this, delivery of relevant information and support on the part of physicians and other health professionals may be of particular use to this population segment.
View details for Web of Science ID A1990DY36400009
View details for PubMedID 2393315
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EFFECTS OF COMMUNITY-WIDE EDUCATION ON CARDIOVASCULAR-DISEASE RISK-FACTORS - THE STANFORD 5-CITY PROJECT
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
1990; 264 (3): 359-365
Abstract
To test whether communitywide health education can reduce stroke and coronary heart disease, we compared two treatment cities (N = 122,800) and two control cities (N = 197,500) for changes in knowledge of risk factors, blood pressure, plasma cholesterol level, smoking rate, body weight, and resting pulse rate. Treatment cities received a 5-year, low-cost, comprehensive program using social learning theory, a communication-behavior change model, community organization principles, and social marketing methods that resulted in about 26 hours of exposure to multichannel and multifactor education. Risk factors were assessed in representative cohort and cross-sectional surveys at baseline and in three later surveys. After 30 to 64 months of education, significant net reductions in community averages favoring treatment occurred in plasma cholesterol level (2%), blood pressure (4%), resting pulse rate (3%), and smoking rate (13%) of the cohort sample. These risk factor changes resulted in important decreases in composite total mortality risk scores (15%) and coronary heart disease risk scores (16%). Thus, such low-cost programs can have an impact on risk factors in broad population groups.
View details for Web of Science ID A1990DN16400032
View details for PubMedID 2362332
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GLUCOREGULATION AND HORMONAL RESPONSES TO MAXIMAL EXERCISE IN NON-INSULIN-DEPENDENT DIABETES
JOURNAL OF APPLIED PHYSIOLOGY
1990; 68 (5): 2067-2074
Abstract
Maximal dynamic exercise results in a postexercise hyperglycemia in healthy young subjects. We investigated the influence of maximal exercise on glucoregulation in non-insulin-dependent diabetic subjects (NIDDM). Seven NIDDM and seven healthy control males bicycled 7 min at 60% of their maximal O2 consumption (VO2max), 3 min at 100% VO2max, and 2 min at 110% VO2max. In both groups, glucose production (Ra) increased more with exercise than did glucose uptake (Rd) and, accordingly, plasma glucose increased. However, in NIDDM subjects the increase in Ra was hastened and Rd inhibited compared with controls, so the increase in glucose occurred earlier and was greater [147 +/- 21 to 169 +/- 19 (30 min postexercise) vs. 90 +/- 4 to 100 +/- 5 (SE) mg/dl (10 min postexercise), P less than 0.05]. Glucose levels remained elevated for greater than 60 min postexercise in both groups. Glucose clearance increased during exercise but decreased postexercise to or below (NIDDM, P less than 0.05) basal levels, despite increased insulin levels (P less than 0.05). Plasma epinephrine and glucagon responses to exercise were higher in NIDDM than in control subjects (P less than 0.05). By use of the insulin clamp technique at 40 microU.m-2.min-1 of insulin with plasma glucose maintained at basal levels, glucose disposal in NIDDM subjects, but not in controls, was enhanced 24 h after exercise. It is concluded that, because of exaggerated counter-regulatory hormonal responses, maximal dynamic exercise results in a 60-min period of postexercise hyperglycemia and hyperinsulinemia in NIDDM. However, this event is followed by a period of increased insulin effect on Rd that is present 24 h after exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1990DG20500044
View details for PubMedID 2193907
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TRAINING EFFECTS OF LONG VERSUS SHORT BOUTS OF EXERCISE IN HEALTHY-SUBJECTS
AMERICAN JOURNAL OF CARDIOLOGY
1990; 65 (15): 1010-1013
Abstract
To evaluate the "threshold" duration of exercise required to produce training effects, 18 healthy men aged 51 +/- 6 years completing 30 minutes of exercise training/day were compared with 18 men aged 52 +/- 6 years completing three 10-minute bouts of exercise/day, each separated by at least 4 hours. Exercise training intensity was moderate (65 to 75% of peak treadmill heart rate). During the 8-week study period VO2 max increased significantly in both groups from 33.3 +/- 3.2 to 37.9 +/- 3.5 ml/kg/min in men performing long exercise bouts and from 32.1 +/- 4.6 to 34.5 +/- 4.5 ml/kg/min in men performing short exercise bouts (p less than 0.05 within and between groups). Adherence to unsupervised exercise training performed at home and at work by men in long and short bouts was high; total duration of training completed was 96 and 93% of the prescribed amount and total number of sessions completed was 92 and 93% of that prescribed, respectively. In both groups exercise heart rate measured by a portable microprocessor was within or above the prescribed range for greater than 85% of the prescribed duration. Thus, multiple short bouts of moderate-intensity exercise training significantly increase peak oxygen uptake. For many individuals short bouts of exercise training may fit better into a busy schedule than a single long bout.
View details for Web of Science ID A1990CY75700010
View details for PubMedID 2327335
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ENERGY-EXPENDITURE INDEX OF WALKING FOR NORMAL-CHILDREN AND FOR CHILDREN WITH CEREBRAL-PALSY
DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY
1990; 32 (4): 333-340
Abstract
Energy expenditure indices (EEI) based on oxygen uptake and heart rate were used to compare the economy of walking at various speeds by normal and cerebral-palsied children. At low walking speeds, EEI values were high, indicating poor economy. At higher speeds the EEI values decreased until a range of maximum economy was reached. For normal children who were capable of walking beyond this range at higher speeds, the EEI increased again. This pattern was noted for both oxygen-uptake and heart-rate indices. Mean EEI values based on oxygen uptake and heart rate for normal children were significantly lower and occurred at faster walking speeds than values for children with cerebral palsy. EEI based on either oxygen uptake or heart rate can be used clinically to provide objective information to help evaluate the influence on gait function of surgical intervention, ambulatory aids or orthotics.
View details for Web of Science ID A1990CV23200008
View details for PubMedID 2332124
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DIFFERENCES IN INSULIN-INDUCED GLUCOSE-UPTAKE AND ENZYME-ACTIVITY IN RUNNING RATS
JOURNAL OF APPLIED PHYSIOLOGY
1990; 68 (2): 513-519
Abstract
To evaluate the relationship between enhanced insulin action and level of exercise training, in vivo glucose uptake was assessed in the absence of added insulin and during insulin-stimulated conditions for three activity levels of voluntarily trained rats (low 2-5 km/day, medium 6-9 km/day, high 11-16 km/day). After rats rested for 24 h and fasted overnight, glucose uptake was estimated by comparing steady-state serum glucose (SSSG) levels at low insulin (SSSI) concentrations achieved during an insulin suppression test. In the absence of added insulin, SSSI averaged approximately 20 microU/ml and glucose uptake was similar for high runners and younger weight-matched controls. However, with insulin added to sustain SSSI at approximately 35 microU/ml, SSSG was significantly reduced in all runners (P less than 0.02), with the lowest value attained in high runners. Fasting serum triglycerides were also reduced in all runners (P less than 0.05), with the lowest values seen in medium and high runners. The concentration of glycogen in liver and select skeletal muscles at the start of the study was not different between trained and control rats, suggesting that enhanced insulin-stimulated glucose uptake was not the result of lower glycogen levels. In addition, glycogen synthase and succinate dehydrogenase activities in biceps femoris muscle were only elevated for high runners, but glycogen synthase activity was not enhanced in plantaris muscle and was decreased in soleus muscle. These findings indicate that enhanced insulin-stimulated glucose uptake and reduced serum triglyceride concentrations induced in exercise-trained rats at varying activity levels are dissociated from changes in glycogen synthase and oxidative enzyme activity for skeletal muscle.
View details for Web of Science ID A1990CQ88000012
View details for PubMedID 2108119
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THE RELATIONSHIP BETWEEN REPRESSIVE AND DEFENSIVE COPING STYLES AND BLOOD-PRESSURE RESPONSES IN HEALTHY, MIDDLE-AGED MEN AND WOMEN
JOURNAL OF PSYCHOSOMATIC RESEARCH
1990; 34 (4): 461-471
Abstract
The current study explored the relationship between repressive coping and blood pressure responses at rest and during a mental challenge. One hundred and twenty healthy, middle-aged men and women completed anxiety and defensiveness measures. Subjects scoring below the median on anxiety and above the median on defensiveness were categorized as repressors; those below the median on both measures as low-anxious; those above the median on anxiety and below the median on defensiveness as moderately anxious; and those above the median on both measures as defensive moderately-anxious. As predicted, repressors showed greater systolic blood pressure reactivity in response to a mental challenge relative to the other groups (p less than 0.01). Repressors also had greater resting systolic blood pressure levels than the other groups (p less than 0.001). The findings are discussed with respect to the potential influence of this response pattern on blood pressure and other CVD risk factors and behaviors.
View details for Web of Science ID A1990DN57200012
View details for PubMedID 2376846
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HEMODYNAMIC AND ADH RESPONSES TO CENTRAL BLOOD-VOLUME SHIFTS IN CARDIAC-DENERVATED HUMANS
CLINICAL PHYSIOLOGY
1990; 10 (1): 55-67
Abstract
Haemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce blood volume shifts in 10 cardiac transplant recipients to assess the contribution of cardiac and vascular volume receptors in the control of ADH secretion. Each subject underwent 15 min of a control period in the seated posture, then assumed a lying posture for 30 min at 6 degrees head-down tilt (HDT) followed by 30 min of seated recovery. Venous blood samples and cardiac dimensions (echocardiography) were taken at 0 and 15 min before HDT, 5, 15 and 30 min of HDT, and 5, 15 and 30 min of seated recovery. Blood samples were analysed for haematocrit, plasma osmolality, plasma renin activity (PRA) and ADH. Resting plasma volume (PV) was measured by Evans blue dye and per cent changes in PV during posture changes were calculated from changes in haematocrit. Heart rate (HR) and blood pressure (BP) were recorded every 2 min. In the cardiac transplant subjects, mean HR decreased (BP less than 0.05) from 102 b.p.m. pre-HDT to 94 b.p.m. during HDT and returned to 101 b.p.m. in seated recovery while BP was slightly elevated (P less than 0.05). PV was increased by 6.3% (P less than 0.05) by the end of 30 min of HDT but returned to pre-HDT levels following seated recovery. Plasma osmolality was not altered by posture changes. Mean left ventricular end-diastolic volume increased (P less than 0.05) from 90 +/- 5 ml pre-HDT to 105 +/- 4 ml during HDT and returned to 88 +/- 5 ml in seated recovery. Plasma ADH was reduced by 28% (P less than 0.05) by the end of HDT and returned to pre-HDT levels with seated recovery. PRA was also reduced by 28% (P less than 0.05) with HDT. These responses were similar to those of six normal cardiac-innervated control subjects and one heart-lung recipient. Therefore, cardiac volume receptors are not the only mechanism for the control of ADH release during acute blood volume shifts in man.
View details for Web of Science ID A1990CH32400005
View details for PubMedID 2302936
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ULTRASONIC TISSUE CHARACTERIZATION WITH A REAL-TIME INTEGRATED BACKSCATTER IMAGING-SYSTEM IN NORMAL AND AGING HUMAN HEARTS
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1989; 14 (7): 1702-1708
Abstract
Experimental studies have shown that variation in the magnitude of integrated ultrasonic backscatter during the cardiac cycle represents acoustic properties of myocardium that are affected by pathologic processes; however, there are few clinical studies using integrated backscatter. Forty subjects without cardiovascular disease (aged 22 to 71 years, mean 41) were studied with use of a new M-mode format integrated backscatter imaging system to characterize the range of cyclic variation of integrated backscatter in normal subjects. Cyclic variation in integrated backscatter was noted in both the septum and the posterior wall in all subjects. The magnitude of the cyclic variation of integrated backscatter and the interval from the onset of the QRS wave of the electrocardiogram to the minimal integrated backscatter value were measured using an area of interest of variable size for integrated backscatter sampling and a software resident in the ultrasound scanner. The magnitude of cyclic variation was larger for the posterior wall than for the septum (6.3 +/- 0.8 versus 4.9 +/- 1.3 dB, p less than 0.01). The interval to the minimal integrated backscatter value was 328 +/- 58 ms for the septum and 348 +/- 42 ms for the posterior wall (p = NS). There was a weak correlation between the magnitude of cyclic variation of integrated backscatter and subject age for the posterior wall (r = -0.47, p less than 0.01), but this was not significant for the septum (r = -0.21) (partially because of inability to exclude specular septal echoes) and septal endocardium.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1989CE08600019
View details for PubMedID 2685077
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EXERCISE-TRAINING PROTOCOLS FOR ASTRONAUTS IN MICROGRAVITY
JOURNAL OF APPLIED PHYSIOLOGY
1989; 67 (6): 2191-2204
Abstract
The question of the composition of exercise protocols for use by astronauts in microgravity is unresolved. Based on our knowledge of physical working requirements for astronauts during intra- and extravehicular activity and on the findings from bed-rest studies that utilized exercise training as a countermeasure for the reduction of aerobic power, deterioration of muscular strength and endurance, decrements in mood and cognitive performance, and possibly for bone loss, two exercise protocols are proposed. One assumes that, during microgravity, astronaut exercise physiological functions should be maintained at 100% of ground-based levels; the other assumes that maximal aerobic power in flight can be reduced by 10% of the ground-based level. A recommended prescription for in-flight prevention or partial suppression of calcium (bone) loss cannot be written until further research findings are obtained that elucidate the site, the magnitude, and the mechanism of the changes. Hopefully these proposed exercise prescriptions will stimulate further research and discussion resulting in even more efficient protocols that will help ensure the optimal health and well-being of our astronauts.
View details for Web of Science ID A1989CG43300001
View details for PubMedID 2691487
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RELATION OF BODY FATNESS AND ITS DISTRIBUTION TO CARDIOVASCULAR RISK-FACTORS IN YOUNG BLACKS AND WHITES - THE ROLE OF INSULIN
AMERICAN JOURNAL OF EPIDEMIOLOGY
1989; 130 (5): 911-924
Abstract
Persons whose body fat is distributed predominantly in the abdomen compared with the hips are at increased risk of several chronic diseases. This study examined the cross-sectional relation of percent body fat, computed from skinfold thickness, and fat distribution, measured by the waist-to-hip girth ratio, to physiologic cardiovascular risk factors in a biracial sample (blacks and whites) of young adults aged 18-30 years. The subjects were persons who were examined at baseline (1984-1986) in the Coronary Artery Risk Development in Young Adults Study in four US metropolitan areas. The two hypotheses tested were that 1) after adjusting for percent body fat, waist-to-hip girth ratio is associated with several physiologic risk factors, and 2) fasting concentrations of serum insulin partly explain such association. Percent body fat was significantly associated with all measured blood lipids, lipoproteins, apolipoproteins, uric acid, and blood pressure. Waist-to-hip girth ratio was significantly, although more weakly, associated in multivariate models with blood concentrations of triglycerides, high density lipoprotein (HDL) cholesterol, HDL2 cholesterol, apolipoproteins A-I and B, low density lipoprotein cholesterol (in women only), uric acid, and systolic blood pressure, but was not associated in either sex with total cholesterol, HDL3 cholesterol, or diastolic blood pressure. Fasting serum insulin concentrations were significantly associated with percent body fat (Pearson r = 0.45-0.53), waist-to-hip girth ratio (Pearson r = 0.18-0.27), and most of the physiologic risk factors. Inclusion of fasting insulin in multivariate models reduced, but rarely eliminated, associations between waist-to-hip girth ratio and the physiologic risk factors. These findings suggest that obese young adults, especially those with abdominal fat preponderance, carry a physiologic profile that places them at higher risk of cardiovascular disease, and that fasting insulin concentrations are only partly explanatory.
View details for Web of Science ID A1989AY60100007
View details for PubMedID 2683750
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Validity and Reliability of Short Physical Activity History: Cardia and the Minnesota Heart Health Program.
Journal of cardiopulmonary rehabilitation
1989; 9 (11): 448-459
Abstract
Validity and reliability of a short physical activity history were assessed in two studies. Validity was studied in 2766 women and 2303 men, participants in CARDIA, a biracial study. Ages ranged from 18 to 30 years. The activities performed in the past 12 months by ≥ 50 percent of participants were walking/hiking, nonstrenuous sports, shoveling/lifting during leisure, running/jogging and home maintenance/gardening. Validity was indirectly assessed by studying the relationships of total activity to skinfold thickness, total caloric intake, duration on a self-limited maximal exercise test, and high density lipoprotein cholesterol. Less than perfect correlation are expected since physical activity is not the only factor affecting the validation criteria and since physical activity patterns change over time within each person. Comparing the highest physical activity quartile to the lowest physical activity quartile, mean level of sum of three skinfolds was 10.7 mm less for women (correlation coefficient (r) = -0.15, P < 0.001) and 6.9 mm less for men (r = -0.12, P < 0.001); mean level of caloric intake was 158 kcal morefor women (r = 0.07, P < 0.001) and 875 kcal morefor men (r = 0.21, P < 0.001); mean level of duration on treadmill was 132 seconds more for women (r = 0.36, P < 0.001) and 95 seconds more for women (r = 0.25, P < 0.001); and mean level of high density lipoprotein cholesterol was 4.8 mg/dL more for women (r = 0.13, P < 0.001) and 3.2 mg/dL more for men (r = 0.11, P < 0.001). Reliability was studied in a separate population by comparing questionnaire results in an initial telephone administration with results obtained two weeks later (N = 129). Similar types and amounts of activity were reported in this group as in the group studied for validity. Test-retest correlation coefficients for three summary scores ranged from 0.77 to 0.84, and were at least 0.57 for each of the 13 activity groupings queried. This questionnaire typically takes 5-10 minutes to administer. It yields moderately detailed information about type and amount of usual leisure time physical activity.
View details for PubMedID 29657358
View details for PubMedCentralID PMC5894828
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TASK-FORCE 2 - DETERMINATION OF OCCUPATIONAL WORKING CAPACITY IN PATIENTS WITH ISCHEMIC HEART-DISEASE
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1989; 14 (4): 1025-1034
View details for Web of Science ID A1989AT81400031
View details for PubMedID 2794263
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ENERGY-COST OF WALKING IN NORMAL-CHILDREN AND IN THOSE WITH CEREBRAL-PALSY - COMPARISON OF HEART-RATE AND OXYGEN-UPTAKE
JOURNAL OF PEDIATRIC ORTHOPAEDICS
1989; 9 (3): 276-279
Abstract
The rate of oxygen uptake can be used to assess energy expenditure during walking, but the necessary instrumentation is cumbersome, expensive, and usually unavailable in the clinical setting. Heart rate is an easily measured parameter, but its use as an index of energy expenditure in children has not been validated previously. We found that the relationship between oxygen uptake and heart rate was linear throughout a wide range of walking speeds for both children with cerebral palsy and normal children. There was no significant difference between the slope or the gamma-intercept of the lines for the two groups. These findings validate the use of heart rate as an index of energy expenditure for normal children and for children with cerebral palsy.
View details for Web of Science ID A1989U380200004
View details for PubMedID 2723046
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VARIATIONS IN RUNNING ACTIVITY AND ENZYMATIC ADAPTATIONS IN VOLUNTARY RUNNING RATS
JOURNAL OF APPLIED PHYSIOLOGY
1989; 66 (3): 1250-1257
Abstract
The running behavior and biochemical markers of oxidative and glycolytic activities associated with voluntary running activity were studied in male Sprague-Dawley rats after 6 wk of training in exercise wheel cages. Twenty-four-hour recordings of running activity were used to quantify the number of individual running bouts, their duration and running speed, and the distance run per day. We then established three categories of voluntary running activity based on the mean distance run per day during the last 3 wk of training: low-activity runners averaged 2-5 km/day, medium runners 6-9 km/day, and high runners greater than 11 km/day. Each group demonstrated an intermittent, nocturnal running pattern, at relatively high intensities, with a similar mean running speed for all groups (avg approximately 45 m/min). Differences in total distance run per day were the result of variations in both the number and duration of individual running bouts. Specifically, high runners (n = 7) had 206 +/- 30 individual running bouts per 24 h, each lasting 87 +/- 7 s; medium runners (n = 7) 221 +/- 22 running bouts, lasting 47 +/- 5 s; and low runners (n = 7) 113 +/- 7 bouts, each lasting 40 +/- 7 s. Voluntary running depressed the rate of body weight gain compared with sedentary control rats, despite an increased food and water intake for all runners. Furthermore, drinking activity was temporally associated with running periods.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1989T698800032
View details for PubMedID 2540143
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INFLUENCE OF REGULAR AEROBIC EXERCISE ON PSYCHOLOGICAL HEALTH - A RANDOMIZED, CONTROLLED TRIAL OF HEALTHY MIDDLE-AGED ADULTS
HEALTH PSYCHOLOGY
1989; 8 (3): 305-324
Abstract
Although a variety of psychological benefits have been attributed to regular exercise, few experimentally controlled studies of healthy individuals currently exist. One hundred twenty healthy, sedentary, middle-aged men and women were randomly assigned to either a 6-month home-based aerobic exercise training program or to an assessment-only control condition. Adherence across the 6-month period was found by both self-report and heart rate microprocessor methods to exceed 75% in both sexes. To assess changes in a variety of psychological variables over time, a 14-item Likert rating scale was completed and returned on a biweekly basis throughout the 6-month period. Slope analyses conducted on the 11 items attaining acceptable test-retest reliability coefficients showed significant between-groups differences on the 3 items most closely associated with the actual physical changes that occurred with exercise (all ps less than .004). Implications in relation to repeated measurement of psychological changes in nonclinical populations and the determination of the relevant population-, activity-, and program-specific parameters involved are discussed.
View details for Web of Science ID A1989AF90200003
View details for PubMedID 2767021
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REGIONAL ADIPOSITY PATTERNS IN RELATION TO LIPIDS, LIPOPROTEIN CHOLESTEROL, AND LIPOPROTEIN SUBFRACTION MASS IN MEN
JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM
1989; 68 (1): 191-199
Abstract
Anatomical adipose tissue distribution patterns are reported to relate to plasma lipids and risk of cardiovascular disease. Waist to hip girth ratios (WHR) and subscapular 10 triceps skinfold thickness ratios (STR) were compared with percent body fat and body mass index values as correlates of plasma lipids and lipoprotein cholesterol and serum lipoprotein subfraction mass by analytic ultracentrifugation in 81 sedentary middle-aged men in a typical range of adiposity. WHR was significantly and positively correlated with plasma concentrations of triglycerides, cholesterol, and low and very low density lipoprotein (LDL and VLDL) cholesterol and inversely correlated with high density lipoprotein (HDL) cholesterol. STR followed these trends, though less strongly, in relation to plasma triglycerides, VLDL cholesterol, and HDL cholesterol. Pronounced differences were found between regional adiposity patterns in their relationships to lipoprotein subfractions, as determined by analytic ultracentrifugation. WHR was negatively correlated with HDL2 (flotation rate F(1.2) 3.5-9), positively with small LDL (S.f 0-7), intermediate density lipoprotein (S.f 12-20), and VLDL (S.f 20-400), while STR correlated with larger LDL (S.f 7-12) and larger VLDL (S.f 60-400). Overall adiposity was not significantly associated with plasma lipoprotein levels after adjusting for regional adiposity patterns. Plasma sex hormone-binding globulin and percent free testosterone were associated with regional adiposity, but did not account for the correlations between WHR and lipoproteins. WHR and STR are measures of fat distribution that correlate with plasma lipoprotein profiles consistent with cardiovascular disease risk and have different relationships to lipoprotein mass subfractions.
View details for Web of Science ID A1989R678200031
View details for PubMedID 2909551
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PHYSICAL-FITNESS AS A PREDICTOR OF CARDIOVASCULAR MORTALITY IN ASYMPTOMATIC NORTH-AMERICAN MEN - THE LIPID RESEARCH CLINICS MORTALITY FOLLOW-UP-STUDY
NEW ENGLAND JOURNAL OF MEDICINE
1988; 319 (21): 1379-1384
Abstract
Limited data are available on the relation between physical fitness and mortality from cardiovascular disease. We examined this question in a study of 4276 men, 30 to 69 years of age, whom we followed for an average of 8.5 years. Examinations at base line included assessment of conventional coronary risk factors and treadmill exercise testing. The heart rate during submaximal exercise (stage 2 of the exercise test) and the duration of exercise were used as measures of physical fitness. Men with incomplete data (n = 308) or who were using cardiovascular drugs (n = 213) were excluded from the analysis. Men who had clinical evidence of cardiovascular disease at base line (n = 649) were analyzed separately. Forty-five deaths from cardiovascular causes occurred among the remaining 3106 men. A lower level of physical fitness was associated with a higher risk of death from cardiovascular and coronary heart disease, after adjustment for age and cardiovascular risk factors. The relative risk of death from cardiovascular causes was 2.7 (95 percent confidence interval, 1.4 to 5.1; P = 0.003) for healthy men with an increment of 35 beats per minute in the heart rate during stage 2, and 3.0 (95 percent confidence interval, 1.6 to 5.5; P = 0.0004) for those with a decrement of 4.4 minutes in the exercise time spent on the treadmill. The corresponding values for death from coronary heart disease were 3.2 (95 percent confidence interval, 1.5 to 6.7; P = 0.003) and 2.8 (95 percent confidence interval, 1.3 to 6.1; P = 0.007), respectively. We conclude that a lower level of physical fitness is associated with a higher risk of death from coronary heart disease and cardiovascular disease in clinically healthy men, independent of conventional coronary risk factors.
View details for Web of Science ID A1988Q991900004
View details for PubMedID 3185648
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CHANGES IN PLASMA-LIPIDS AND LIPOPROTEINS IN OVERWEIGHT MEN DURING WEIGHT-LOSS THROUGH DIETING AS COMPARED WITH EXERCISE
NEW ENGLAND JOURNAL OF MEDICINE
1988; 319 (18): 1173-1179
Abstract
We studied separately the influence of two methods for losing fat weight on the levels of plasma lipids and lipoproteins in overweight sedentary men--decreasing energy intake without increasing exercise (diet), and increasing energy expenditure without altering energy intake (exercise, primarily running)--in a one-year randomized controlled trial. As compared with controls (n = 42), dieters (n = 42) had significant loss of total body weight (-7.8 +/- 0.9 kg [mean +/- SE]), fat weight (-5.6 +/- 0.8 kg), and lean (non-fat) weight (-2.1 +/- 0.5 kg) (P less than 0.001 for each variable), and exercisers (n = 47) had significant loss of total body weight (-4.6 +/- 0.8 kg) and fat weight (-3.8 +/- 0.7 kg) (P less than 0.001 for both variables) but not lean weight (-0.7 +/- 0.4 kg). Fat-weight loss did not differ significantly between dieters and exercisers. All subjects were discouraged from altering their diet composition; however, dieters and exercisers had slight reductions in the percentage of kilojoules derived from fat. As compared with the control group, both weight-loss groups had significant increases (P less than 0.01) in plasma concentrations of high-density lipoprotein (HDL) cholesterol (diet vs. exercise, 0.13 +/- 0.03 vs. 0.12 +/- 0.03 mmol per liter), HDL2 cholesterol (0.07 +/- 0.02 vs. 0.07 +/- 0.02 mmol per liter), and HDL3 cholesterol (0.07 +/- 0.02 vs. 0.06 +/- 0.02 mmol per liter) and significant decreases (P less than 0.05) in triglyceride levels (diet vs. exercise, -0.35 +/- 0.14 vs. -0.24 +/- 0.12 mmol per liter). Levels of total and low-density lipoprotein cholesterol were not significantly changed, relative to values in controls. None of these changes were significantly different between dieters and exercisers. Thus, we conclude that fat loss through dieting or exercising produces comparable and favorable changes in plasma lipoprotein concentrations.
View details for Web of Science ID A1988Q697500001
View details for PubMedID 3173455
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RESTORATION AND MAINTENANCE OF PHYSICAL AND PSYCHOLOGIC FUNCTION IN PATIENTS WITH ISCHEMIC HEART-DISEASE
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1988; 12 (4): 1117-1119
View details for Web of Science ID A1988Q306500042
View details for PubMedID 3417987
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ELEMENTS AND EVALUATION OF PHYSICAL-ACTIVITY IN THE PREVENTION AND MANAGEMENT OF ISCHEMIC HEART-DISEASE
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1988; 12 (4): 1091-1095
View details for Web of Science ID A1988Q306500035
View details for PubMedID 3417982
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EFFECTS OF WEIGHT-LOSS ON CLINIC AND AMBULATORY BLOOD-PRESSURE IN NORMOTENSIVE MEN
AMERICAN JOURNAL OF CARDIOLOGY
1988; 62 (1): 89-93
Abstract
Obesity and physical inactivity are associated with both elevated cardiovascular risk and blood pressure (BP), but the interrelation of exercise, weight loss and BP is poorly understood. This study examines the independent effects of exercise and weight loss on both standard clinic and automated, ambulatory BP in 115 overweight, sedentary, normotensive men (aged 30 to 59 years) who were randomly assigned to control status or to lose weight over 1 year by moderate caloric restriction (dieting) or by increased caloric expenditure (exercise). Median daytime and evening BP were determined from measurements made every 20 minutes while the subjects were awake. After 1 year, the control group gained (mean +/- standard deviation) 0.5 +/- 3.8 kg while the diet group lost 6.9 +/- 4.4 kg and the exercise group lost 4.6 +/- 3.5 kg. Clinic BP decreased similarly in all 3 groups, but daytime and evening ambulatory BP decreased in both intervention groups and increased in the control group. Relative to the 1-year change in control subjects, net change in daytime ambulatory BP averaged -2 to -3 mm Hg in both dieters and exercisers, while net change in evening ambulatory BP averaged -3 to -4 mm Hg. These changes were all statistically significant (p less than 0.05) when compared with control subjects except for daytime systolic BP in both intervention groups and evening diastolic BP in dieters. Weight loss achieved through caloric restriction or expenditure may cause important decreases in BP in normotensive men; exercise appears to confer no unique benefit. If confirmed, these results have important public health implications for the prevention of cardiovascular disease.
View details for Web of Science ID A1988P035300015
View details for PubMedID 3381757
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EFFECTS OF SOLID AND LIQUID GUAR GUM ON PLASMA-CHOLESTEROL AND TRIGLYCERIDE CONCENTRATIONS IN MODERATE HYPERCHOLESTEROLEMIA
AMERICAN JOURNAL OF CARDIOLOGY
1988; 62 (1): 51-55
Abstract
Guar gum is a dietary fiber reported to decrease plasma cholesterol concentration. This study investigated the effect of guar therapy in 50 men with moderately elevated plasma cholesterol who were randomized to an 8-week study of guar therapy. Three forms of guar gum were used: a medium viscosity solid or liquid form, a high viscosity liquid form or placebo. When the medium viscosity guar therapy groups were combined, 4 weeks of therapy were shown to result in a substantial reduction in total and low density lipoprotein (LDL) cholesterol of 25 mg/dl and 23 mg/dl (p = 0.035 and 0.12), respectively. The high viscosity guar group had a reduction in total cholesterol and LDL cholesterol of 37 and 30 mg/dl, respectively (p less than 0.003 and p less than 0.02). Following 8 weeks of therapy, a return toward baseline values was observed. No significant changes were demonstrated in blood chemistries, triglyceride values, total high density lipoprotein (HDL) cholesterol or the HDL2 fraction of HDL cholesterol. The effect of the solid and liquid forms of guar on plasma cholesterol reduction was similar. This study shows that a nonpharmacologic dietary additive reduces plasma total and LDL cholesterol.
View details for Web of Science ID A1988P035300008
View details for PubMedID 2837895
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INCREASING EXERCISE AMONG BLUE-COLLAR EMPLOYEES - THE TAILORING OF WORKSITE PROGRAMS TO MEET SPECIFIC NEEDS
PREVENTIVE MEDICINE
1988; 17 (3): 357-365
Abstract
Despite increasing interest in worksite exercise programs, little attention has been focused on the blue-collar segment of the workforce. Because of their low participation in traditional exercise classes and programs, blue-collar workers at a university were targeted for an exercise program tailored specifically to their preferences and needs. Thirty-eight sedentary males employed in operations and maintenance shops on the university campus were evaluated with regard to their current exercise behavior, other health habits, and their preferred types of physical activity programs. A pre- and postprogram submaximal exercise test, weight, and blood pressure measurements were also completed on-site. Twenty-two men (23% of the total blue-collar population) subsequently participated in a 16-week exercise program using an on-site parcourse, and incorporating such motivational strategies as public monitoring, intershop competition, and activity-based incentives. Participation rates were substantially higher than those recorded for previous worksite exercise classes. Participants showed increases in fitness levels (P less than 0.0001) and decreases in weight (P less than 0.05) compared with nonparticipants. Suggestions concerning recruitment of such individuals into low-cost exercise programs and subsequent participation maintenance are discussed.
View details for Web of Science ID A1988P076900010
View details for PubMedID 3405990
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STRATEGIES FOR INCREASING EARLY ADHERENCE TO AND LONG-TERM MAINTENANCE OF HOME-BASED EXERCISE TRAINING IN HEALTHY MIDDLE-AGED MEN AND WOMEN
AMERICAN JOURNAL OF CARDIOLOGY
1988; 61 (8): 628-632
Abstract
Two studies were undertaken to compare strategies for the adoption and maintenance of moderate-intensity, home-based exercise training. In the study of adoption, 52 men and women who had served for 6 months as controls for a study of moderate-intensity, home-based exercise training received 30 minutes of baseline instruction. They were then randomized to receive continuing instruction and support through 10 staff-initiated telephone contacts of 5 minutes each every 2 weeks, or to receive no telephone contacts. In subjects receiving telephone contacts, peak oxygen uptake increased significantly after 6 months, whereas no increase was observed in subjects receiving no staff support (p less than 0.05). In the maintenance study, 51 men and women who had significantly increased their peak oxygen uptake by 6 months of moderate-intensity, home-based exercise training were randomized to undergo daily self-monitoring and receive adherence instructions, or undergo weekly self-monitoring only, during a second 6-month period of training. Subjects performing daily self-monitoring reported completing significantly more exercise training sessions during the 6 months of training than subjects performing weekly self-monitoring; functional capacity in both groups remained higher than before training (p less than 0.05). Taken together, these studies suggest that brief baseline instruction followed by continuing telephone contact with staff can be used to help people adopt a moderate-intensity, home-based exercise training program that can be maintained by simple self-monitoring strategies.
View details for Web of Science ID A1988N611800025
View details for PubMedID 3344690
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SMOKING CESSATION AFTER ACUTE MYOCARDIAL-INFARCTION - THE EFFECTS OF EXERCISE TRAINING
ADDICTIVE BEHAVIORS
1988; 13 (4): 331-335
Abstract
To determine the influence of exercise training on smoking after acute myocardial infarction (AMI), smoking rates in 42 pre-AMI smokers assigned to exercise training were compared with 26 pre-AMI smokers assigned to no training. Exercise training occurred 3-26 weeks after AMI. The increase in functional capacity in 3-26 weeks was significantly greater in training than in no-training patients: 1.8 vs. 1.2 METs respectively (p less than 0.05). Adherence to exercise training was higher in non-smokers and former smokers than in those who continued to smoke: 89% and 88% vs. 80% respectively (NS). The prevalence of smoking 6 months post-AMI was lower in training than in no-training patients: 31% vs. 39% respectively (NS). Plasma thiocyanates collected on a random sample of 42 patients suggested that 19% of patients who are smoking after MI fail to report doing so. Self-reported cigarette consumption at 28 weeks was half as great in training as in no-training patients: 11 +/- 7 vs. 22 +/- 16 cigarettes per day (p less than 0.03). Firm advice to stop smoking followed by medically supervised exercise training with frequent followup reduces self-reported cigarette consumption in patients after AMI.
View details for Web of Science ID A1988Q956300003
View details for PubMedID 3239464
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NEW METHODOLOGIES FOR STUDYING THE PREVENTION OF ATHEROSCLEROSIS
ANNALS OF CLINICAL RESEARCH
1988; 20 (1-2): 39-45
Abstract
To determine if multiple risk factor modification favorably alters the rate of progression of coronary atherosclerosis, 300 patients with established atherosclerosis have been randomized into a clinical trial; 155 to usual care and 145 to special intervention. All patients have medical/risk examinations at baseline and annually for 4 years. The special intervention patients undergo aggressive risk factor management with emphasis on lipoprotein modification, dietary management, smoking abatement, blood pressure control, weight loss and increased physical activity. To measure progression of atherosclerosis, a quantitative, computer-assisted coronary arteriographic system was developed to analyze the baseline and 4-year follow-up arteriograms. This procedure uses a catheter with a metallic calibration cylinder at its tip to determine absolute artery size and automated computer edge detection techniques to define the internal border of the artery. The analysis system detects artery borders using changes in cine film density and measures distances between these borders. For each segment the minimum, maximum and mean diameters are measured and percent stenosis and atheroma area calculated. This system provides precise and reproducible measures of coronary artery segment diameter. Using this technique, we estimate a 33% reduction in the rate of coronary artery progression over 4 years, defined as mean segment diameter, can be detected at a power of 0.80 and an alpha of 0.05 (one tailed test) with a sample size of 120 in each of 2 groups.
View details for Web of Science ID A1988P181700007
View details for PubMedID 3408211
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IMPROVED INSULIN ACTION IN MUSCLE, LIVER, AND ADIPOSE-TISSUE IN PHYSICALLY TRAINED HUMAN-SUBJECTS
AMERICAN JOURNAL OF PHYSIOLOGY
1987; 253 (5): E489-E495
Abstract
The present studies were initiated to assess the effect of insulin on muscle, liver, and adipose tissue in eight control and eight physically trained individuals matched for age and body mass index. Results indicated that percent body fat was 53% lower and maximal oxygen consumption 50% higher in physically trained subjects. Although the plasma glucose response to a standard oral glucose challenge was similar in the two groups, the insulin response was significantly lower in the trained individuals (P less than 0.001). Mean (+/- SE) insulin-stimulated glucose uptake, quantified in vivo by the euglycemic hyperinsulinemic clamp technique, was significantly greater in physically trained individuals at steady-state plasma insulin concentrations of approximately 10 microU/ml (3.41 +/- 0.14 vs. 2.73 +/- 0.22 mg.kg fat free mass-1.min-1, P less than 0.05) and 50 microU/ml (13.58 +/- 0.75 vs. 9.82 +/- 0.53 mg.kg fat free mass-1.min-1, P less than 0.001). In addition, mean (+/- SE) hepatic glucose production rate was lower in physically trained subjects at insulin levels of 10 microU/ml (0.63 +/- 0.19 vs. 1.19 +/- 0.22 mg.kg body wt-1.min-1, P less than 0.05) and 50 microU/min (0.18 +/- 0.14 vs. 0.60 +/- 0.17 mg.kg body wt-1.min-1, P less than 0.05). Finally, the ability of insulin to stimulate mean (+/- SE) glucose uptake above basal levels was greater in adipocytes isolated from trained individuals (94 +/- 10 vs. 56 +/- 14 fl.cell-1.s-1, P less than 0.01). On the other hand, no difference in specific binding of insulin to its receptor on monocytes was noted between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1987L134800018
View details for PubMedID 3318492
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EFFECTIVENESS OF SELF-MONITORED, HOME-BASED, MODERATE-INTENSITY EXERCISE TRAINING IN MIDDLE-AGED MEN AND WOMEN
AMERICAN JOURNAL OF CARDIOLOGY
1987; 60 (1): 66-70
Abstract
The effects of 6 months of self-monitored, home-based exercise training on maximal oxygen uptake (VO2 max), body composition and plasma lipid levels of healthy, sedentary, middle-aged persons were evaluated in 60 men, aged 49 +/- 6 years, and 60 women, aged 47 +/- 5 years. Moderate-intensity training was performed 5 times per week in sessions of 47 +/- 7 minutes and 54 +/- 8 minutes for men and women, respectively. The individually prescribed range of heart rate corresponded to 65 to 77% of the peak value during symptom-limited treadmill testing (mean of 72% for men and 69% for women). Caloric expenditure per training session was approximately 345 kcal for men and 235 kcal for women. VO2 max increased 15% in men and 9% in women (both p less than 0.01). The greater increase in VO2 max in men than in women primarily reflected greater adherence to training in men (greater than or equal to 90% vs greater than or equal to 75%). The increase in VO2 max in women who showed very high adherence was comparable to that of men. Body weight decreased, by 1.5 +/- 10 kg, in men (p less than 0.05) but not in women undergoing training. No significant training-induced changes in plasma lipid levels were noted in either men or women. Baseline orientation and follow-up telephone calls required less than 1 hour of staff time per participant. Self-monitored, moderate-intensity, home-based exercise training significantly increases functional capacity in healthy, middle-aged men and women. Such training provides an alternative to group-based exercise training.
View details for Web of Science ID A1987J057400015
View details for PubMedID 3604945
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THE INTERACTION OF EXERCISE TRAINING AND BETA-BLOCKADE IN PATIENTS WITH MODERATE HYPERTENSION
ELSEVIER SCIENCE INC. 1987: A235–A235
View details for Web of Science ID A1987F937000938
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MAINTENANCE OF MODERATE INTENSITY HOME-BASED EXERCISE TRAINING IN HEALTHY-MEN AND WOMEN
LIPPINCOTT WILLIAMS & WILKINS. 1986: 504–
View details for Web of Science ID A1986E489402007
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EFFECTS OF LOW-INTENSITY AND HIGH-INTENSITY HOME-BASED EXERCISE TRAINING ON FUNCTIONAL-CAPACITY IN HEALTHY MIDDLE-AGED MEN
AMERICAN JOURNAL OF CARDIOLOGY
1986; 57 (6): 446-449
Abstract
The effects of 12 weeks of home-based exercise training on peak oxygen consumption (VO2 max) in healthy sedentary middle-aged men, mean age 49 +/- 6 years, were evaluated. Twenty-one men trained at low intensity, 23 trained at high intensity and 20 were control subjects. Individually prescribed low- and high-intensity training was performed 5 times per week within a range of 42 to 60% and 63 to 81% of baseline VO2 max, corresponding to average heart rates of 102 to 122 and 128 to 148 beats/min, respectively. Caloric expenditure per training session approximated 350 kcal in both groups; adherence was at least 90% in both groups. VO2 max increased 8% in patients who trained at low intensity, 17% in those who trained at high intensity (both p less than 0.001), and not at all in control subjects. Low-intensity exercise training at home significantly augments functional capacity in healthy sedentary middle-aged men.
View details for Web of Science ID A1986A133000014
View details for PubMedID 3946263
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SELF-MONITORED HOME-BASED MODERATE INTENSITY EXERCISE IN MEN AND WOMEN - EFFECTS ON FUNCTIONAL-CAPACITY
ELSEVIER SCIENCE INC. 1986: A223–A223
View details for Web of Science ID A1986A165000888
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MEDICALLY DIRECTED AT-HOME REHABILITATION SOON AFTER CLINICALLY UNCOMPLICATED ACUTE MYOCARDIAL-INFARCTION - A NEW MODEL FOR PATIENT-CARE
AMERICAN JOURNAL OF CARDIOLOGY
1985; 55 (4): 251-257
Abstract
Medically directed at-home rehabilitation was compared with group rehabilitation which began 3 weeks after clinically uncomplicated acute myocardial infarction (AMI) in 127 men, mean age 53 +/- 7 years. Between 3 and 26 weeks after AMI, adherence to individually prescribed exercise was equally high (at least 71%), the increase in functional capacity equally large (1.8 +/- 1.0 METs) and nonfatal reinfarction and dropout rates equally low (both 3% or less) in the 66 men randomized to home training and the 61 men randomized to group training. No training-related complications occurred in either group. The low rate of reinfarction and death (5% and 1%, respectively) in the study as a whole, which included 34 patients with no training and 37 control patients, reflected a stepwise process of clinical evaluation, exercise testing at 3 weeks and frequent telephone surveillance of patients who underwent exercise training. Medically directed at-home rehabilitation has the potential to increase the availability and to decrease the cost of rehabilitating low-risk survivors of AMI.
View details for Web of Science ID A1985ABD8800001
View details for PubMedID 3969859
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EFFECT OF HABITUAL PHYSICAL-ACTIVITY ON REGULATION OF INSULIN-STIMULATED GLUCOSE DISPOSAL IN OLDER MALES
JOURNAL OF THE AMERICAN GERIATRICS SOCIETY
1985; 33 (4): 273-277
Abstract
The goal of this study was to evaluate the effect of differences in habitual level of physical activity on insulin action in healthy males between 60 and 75 years of age. The study population consisted of 20 non-obese individuals with normal glucose tolerance: 13 older subjects (68 +/- 4 years) not exercising regularly and 7 older subjects (66 +/- 3 years) who exercised regularly. Measurements were made of body mass index (BMI), percentage body fat by underwater weighing, maximal O2 consumption by bicycle ergometry (VO2max), and insulin-stimulated glucose disposal by the insulin clamp technique. The results demonstrated that insulin-stimulated glucose disposal was significantly increased (P less than 0.001) in the normal older subjects who exercised regularly. Furthermore, a direct relationship (r = 0.74, P less than 0.001) existed between maximal aerobic capacity and in vivo insulin action, which was independent of either BMI or percentage body fat. These data are consistent with the view that the extensive variation previously noted in in vivo insulin-stimulated glucose disposal of older subjects is related to differences in habitual physical activity.
View details for Web of Science ID A1985AFY3000010
View details for PubMedID 3886766
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EXERCISE TRAINING DURING LONG-TERM BETA-BLOCKADE TREATMENT IN HEALTHY-SUBJECTS
AMERICAN JOURNAL OF CARDIOLOGY
1985; 55 (10): D101-D109
View details for Web of Science ID A1985AGH4300017
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PHYSICAL-ACTIVITY ASSESSMENT METHODOLOGY IN THE 5-CITY PROJECT
AMERICAN JOURNAL OF EPIDEMIOLOGY
1985; 121 (1): 91-106
Abstract
Previous measures of physical activity for epidemiologic studies were considered inadequate to meet the needs of a community-based health education trial. Therefore, new methods of quantifying the physical activity habits of communities were developed which are practical for large health surveys, provide information on the distribution of activity habits in the population, can detect changes in activity over time, and can be compared with other epidemiologic studies of physical activity. Independent self-reports of vigorous activity (at least 6 metabolic equivalents (METs) ), moderate activity (3-5 METs), and total energy expenditure (kilocalories per day) are described, and the physical activity practices of samples of California cities are presented. Relationships between physical activity measures and age, education, occupation, ethnicity, marital status, and body mass index are analyzed, and the reliabilities of the three activity indices are reported. The new assessment procedure is contrasted with nine other measures of physical activity used in community surveys.
View details for Web of Science ID A1985TX93500011
View details for PubMedID 3964995
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METABOLISM OF SUBSTRATES - DIET, LIPOPROTEIN METABOLISM, AND EXERCISE
FEDERATION PROCEEDINGS
1985; 44 (2): 358-363
Abstract
The major classes of serum lipoproteins have been shown to be differentially affected not only by dietary factors but also by levels of physical activity. Individuals engaging in relatively higher amounts of physical activity tend to have lower levels of low-density lipoprotein cholesterol (LDL-C) and very-low-density lipoprotein cholesterol (VLDL-C) and higher levels of high-density lipoprotein cholesterol (HDL-C) than their sedentary counterparts. However, higher levels of physical activity are also associated with lower adiposity and elevated caloric intake, two factors that themselves have independent roles in the regulation of lipoprotein levels. Changes in adiposity appear to be responsible for some, but not all, of the lipoprotein change associated with exercise. A study in which 14 sedentary, middle-aged men engaged in a progressive running program over 2 years showed increased HDL-C and decreased LDL-C, both considered antiatherogenic. Adiposity, expressed as percent body fat, decreased during the study whereas caloric intake, notably in the form of carbohydrates, increased. Elevated physical activity levels alter the relationships among adiposity, dietary intake, and lipoproteins that prevail in the sedentary state.
View details for Web of Science ID A1985AEP5100017
View details for PubMedID 3881291
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ASSOCIATIONS OF RESTING HEART-RATE WITH CONCENTRATIONS OF LIPOPROTEIN SUBFRACTIONS IN SEDENTARY MEN
CIRCULATION
1985; 71 (3): 441-449
Abstract
In major prospective studies it has been reported that high heart rate at rest predicts the development of coronary heart disease (CHD) or cardiovascular disease (CVD) in men, but the mechanisms producing these relationships are unknown. Since lipoprotein levels contribute strongly to the risk of CHD and CVD, we examined the relationship of resting heart rate to plasma concentrations of high-density (HDL), low-density (LDL), and very low-density (VLDL) lipoproteins, apolipoprotein (apo) A-I and A-II, and serum concentrations of lipoprotein subfractions in 81 men to determine if atherogenic lipoproteins could potentially induce the reported association of heart rate with development of CHD or CVD. The significant (p less than or equal to .05) Spearman's correlations for resting heart rate vs HDL2 mass (rs = -.24), HDL3 mass (rs = -.40), HDL cholesterol (rs = -.36), apo A-I (rs = -.29), triglycerides (rs = .31), VLDL cholesterol (rs = .24), VLDL mass (rs = .27), and LDL mass of Sof 0-7 subfraction (rs = .30) lend support to our hypothesis of lipoprotein-induced relationships of CHD with heart rate. The correlations for resting heart rate vs triglycerides, HDL cholesterol, HDL3 mass, VLDL mass, and LDL mass of Sof 0-7 subfraction remain significant when adjusted for adiposity, age, smoking habits, diet, and physical fitness as measured by maximum aerobic power (VO2 max) or submaximal heart rate during a graded exercise test.
View details for Web of Science ID A1985ACM7500007
View details for PubMedID 3918806
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PHYSICAL-ACTIVITY AND EXERCISE TO ACHIEVE HEALTH RELATED PHYSICAL-FITNESS COMPONENTS
PUBLIC HEALTH REPORTS
1985; 100 (2): 202-212
Abstract
To improve health and fitness effectively through physical activity or exercise, we need to understand how this comes about. For many of these changes, the stimulus has been grossly defined in terms of type, intensity, duration, and frequency of exercise, but for others a dose-response relationship has not been determined. Physical activity that appears to provide the most diverse health benefits consists of dynamic, rhythmical contractions of large muscles that transport the body over distance or against gravity at a moderate intensity relative to capacity for extended periods of time during which 200 to 400 kilocalories (or 4 kilocalories per kilogram of body weight) are expended. For optimal health benefits, such activity should be performed daily or at least every other day and should be supplemented with some heavy resistance and flexibility exercises. The greatest benefits are achieved when the least active individuals become moderately active; much less benefit is apparent when the already active individual becomes extremely active. Overexertion or inappropriate exercise can produce significant health risks. Research is needed to characterize better the health-promoting features of physical activity and exercise.
View details for Web of Science ID A1985AFX9800013
View details for PubMedID 3920719
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ASSESSMENT OF HABITUAL PHYSICAL-ACTIVITY BY A 7-DAY RECALL IN A COMMUNITY SURVEY AND CONTROLLED EXPERIMENTS
AMERICAN JOURNAL OF EPIDEMIOLOGY
1985; 122 (5): 794-804
Abstract
Assessment of habitual physical activity in epidemiologic and health education studies has been difficult. A seven-day physical activity recall interview was developed and administered in a community health survey, a randomized clinical trial, and two worksite health promotion programs during 1979-1982. These studies were conducted in several populations in California, Texas, Pennsylvania, and New Jersey. Energy expenditure estimates from the physical activity recall conformed to expected age- and sex-specific values in the cross-sectional community survey. Estimates of energy expenditure were also congruent with other questions on physical activity and job classification. In a randomized, one-year exercise trial, the physical activity recall detected increases in energy expenditure in the treated group and was positively associated with miles run during training (p less than 0.05). Changes in energy expenditure were associated with changes in maximal oxygen uptake (VO2max (r = 0.33, p less than 0.05) and body fatness (r = -0.50, p less than 0.01) at six months, and in high density lipoprotein-cholesterol (r = 0.31, p less than 0.05) and triglyceride (r = -0.41, p less than 0.01) at one year. The physical activity recall detected significant (p less than 0.01) increases in energy expenditure in treatment groups in two worksite health promotion projects. These data suggest that the physical activity recall provides useful estimates of habitual physical activity for research in epidemiologic and health education studies.
View details for Web of Science ID A1985AST7600009
View details for PubMedID 3876763
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7-DAY ACTIVITY AND SELF-REPORT COMPARED TO A DIRECT MEASURE OF PHYSICAL-ACTIVITY
AMERICAN JOURNAL OF EPIDEMIOLOGY
1984; 120 (6): 818-824
Abstract
To determine how well a seven-day interview-administered activity recall used in a large epidemiologic study at Stanford University reflected seven days of self-reported activity and directly measured physical activity, 30 white males, mean age 52 years, recorded daily physical activity for a week, and half of these wore an ambulatory solid-state minicomputer (Vitalog) which measures continuous heart rate and motion. Total hours of moderate, hard, and hard plus very hard activity were not significantly different for weekdays and weekends for self-report and recall and were significantly correlated. Total energy expenditure for subjects wearing the Vitalog averaged 38.5 +/- 6.7 kcal/kg/day compared to an average of 37.7 +/- 4.5 kcal/kg/day for recall or 39.6 +/- 7.2 kcal/kg/day for self-report. Conditioning activities are best remembered followed by home or leisure and job activities. Mean hours of sleep per week night were significantly greater reported by self-report than reported by recall, but the two were significantly correlated. It is concluded that a seven-day activity recall accurately reflects mean kcal/day expenditure, with conditioning activities being the best recalled. A self-report log used in conjunction with an interview-based seven-day recall might maximize accuracy of recall.
View details for Web of Science ID A1984TV88100003
View details for PubMedID 6507425
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COMPARISON OF CARDIOVASCULAR-RESPONSE TO COMBINED STATIC-DYNAMIC EFFORT, POSTPRANDIAL DYNAMIC EFFORT AND DYNAMIC EFFORT ALONE IN PATIENTS WITH CHRONIC ISCHEMIC-HEART-DISEASE
CIRCULATION
1982; 65 (7): 1411-1419
Abstract
The cardiovascular responses to combined static-dynamic effort, postprandial dynamic effort and dynamic effort alone were evaluated by upright bicycle ergometry during equilibrium-gated blood pool scintigraphy in 24 men, mean age 59 +/- 8 years, with chronic ischemic heart disease. Combined static-dynamic effort and the postprandial state elicited a peak cardiovascular response similar to that of dynamic effort alone; work load 643 +/- 156 and 638 +/- 161 vs 650 +/- 153 kg-m/min, respectively; heart rate 147 +/- 14 and 145 +/- 14 vs 143 +/- 17 beats/min; systolic pressure 195 +/- 26 and 200 +/- 25 vs 197 +/- 25 mm Hg; and rate-pressure product 286 +/- 48 and 292 +/- 55 vs 282 +/- 52. Heart rate, intraarterial systolic and diastolic pressures, rate-pressure product and ejection fraction were similar for the three test conditions at the onset of ischemia and at peak effort. The prevalence and extent of exercise-induced ischemic left ventricular dysfunction, ST-segment depression, angina pectoris and ventricular ectopic activity were also similar during the three test conditions. Direct and indirect measurements of systolic and diastolic blood pressure were highly correlated. The onset of ischemic ST-segment depression and angina pectoris correlated as strongly with heart rate alone as with the rate-pressure product during all three test conditions. The cardiovascular response to combined static-dynamic effort and to postprandial dynamic effort becomes more similar to that of dynamic effort alone as dynamic effort reaches a symptom limit. If significant ischemic and arrhythmic abnormalities are absent during symptom-limited dynamic exercise testing, they are unlikely to appear during combined static-dynamic or postprandial dynamic effort. This simplifies, the task of formulating guidelines for physical effort in patients with chronic ischemic heart disease, especially in providing "clearance" to perform avocational and vocational tasks involving combined static-dynamic and postprandial dynamic effort.
View details for Web of Science ID A1982NS55500018
View details for PubMedID 6280892