https://orcid.org/0000-0003-0034-9045All Publications
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The Association Between Physical Activity and Cognition in a Racially/Ethnically Diverse Cohort of Older Adults: Results From the Kaiser Healthy Aging and Diverse Life Experiences Study.
Alzheimer disease and associated disorders
2024
Abstract
Most prior research on physical activity (PA) and cognition is based on predominantly white cohorts and focused on associations of PA with mean (average) cognition versus the distribution of cognition. Quantile regression offers a novel way to quantify how PA affects cognition across the entire distribution.The Kaiser Healthy Aging and Diverse Life Experiences study includes 30% white, 19% black, 25% Asian, and 26% Latinx adults age 65+ living in Northern California (n = 1600). The frequency of light or heavy PA was summarized as 2 continuous variables. Outcomes were z-scored executive function, semantic memory, and verbal episodic memory. We tested associations of PA with mean cognition using linear regression and used quantile regression to estimate the association of PA with the 10th-90th percentiles of cognitive scores.Higher levels of PA were associated with higher mean semantic memory (b = 0.10; 95% CI: 0.06, 0.14) and executive function (b = 0.05; 95% CI: 0.01, 0.09). Associations of PA across all 3 cognitive domains were stronger at low quantiles of cognition.PA is associated with cognition in this racially/ethnically diverse sample and may have larger benefits for individuals with low cognitive scores, who are most vulnerable to dementia.
View details for DOI 10.1097/WAD.0000000000000612
View details for PubMedID 38533734
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Timing and level of educational attainment and late-life cognition in the KHANDLE study.
Alzheimer's & dementia : the journal of the Alzheimer's Association
2023
Abstract
INTRODUCTION: The timing of educational attainment may modify its effects on late-life cognition, yet most studies evaluate education only at a single time point.METHODS: Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study cohort participants (N=554) reported educational attainment (dichotomized at any college education) at two time points, and we classified them as having low, high, or later-life high educational attainment. Linear mixed-effects models estimated associations between educational attainment change groups and domain-specific cognitive outcomes (z-standardized).RESULTS: Compared to low educational attainment, high (beta=0.59 SD units; 95% confidence interval [CI]: 0.39, 0.79) and later-life high educational attainment (beta =0.22; 95% CI: 0.00, 0.44) were associated with higher executive function. Only high educational attainment was associated with higher verbal episodic memory (beta = 0.27; 95% CI: 0.06, 0.48).DISCUSSION: Level and timing of educational attainment are both associated with domain-specific cognition. A single assessment for educational attainment may inadequately characterize protective associations with late-life cognition.HIGHLIGHTS: Few studies have examined both level and timing of educational attainment on cognition. Marginalized populations are more likely to attain higher education in adulthood. Higher educational attainment in late life is also associated with higher cognition.
View details for DOI 10.1002/alz.13475
View details for PubMedID 37751937
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The Mediating Roles of Neurobiomarkers in the Relationship Between Education and Late-Life Cognition.
Journal of Alzheimer's disease : JAD
2023
Abstract
The mediating roles of neuropathologies and neurovascular damage in the relationship between early-life education and later-life cognitive function are unknown.To examine whether Alzheimer's and neurovascular biomarkers mediate the relationships between education and cognitive functions.Data were from 537 adults aged 55-94 in the Alzheimer's Disease Neuroimaging Initiative 3. We tested whether the relationships between education (continuous, years) and cognitive function (memory, executive functioning, and language composites) were mediated by neuroimaging biomarkers (hippocampal volumes, cortical gray matter volumes, meta-temporal tau PET standard uptake value ratio, and white matter hyperintensity volumes). Models were adjusted for age, race, sex/gender, cardiovascular history, body mass index, depression, and Apolipoprotein E-ɛ4 status.Hippocampal volumes and white matter hyperintensities partially mediated the relationships between education and cognitive function across all domains (6.43% to 15.72% mediated). The direct effects of education on each cognitive domain were strong and statistically significant.Commonly measured neurobiomarkers only partially mediate the relationships between education and multi-domain cognitive function.
View details for DOI 10.3233/JAD-230244
View details for PubMedID 37694365
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Association of primary lifetime occupational cognitive complexity and cognitive decline in a diverse cohort: Results from the KHANDLE study.
Alzheimer's & dementia : the journal of the Alzheimer's Association
2023
Abstract
INTRODUCTION: Higher occupational complexity has been linked to favorable cognitive outcomes, but rarely examined in racially and ethnically diverse populations.METHODS: In a diverse cohort (n=1536), linear mixed-effects models estimated associations between main lifetime occupational complexity and domain-specific cognitive decline (z-standardized). Occupational complexity with data, people, and things were classified using the Dictionary of Occupational Titles.RESULTS: For occupational complexity with data, highest tertile (vs. lowest) was associated with higher baseline executive function (beta=0.11; 95% confidence interval [CI] 0.00-0.22) and slower annual rate of decline (beta=0.03; 95% CI 0.01-0.06), and higher baseline semantic memory (beta=0.14; 95% CI 0.04-0.25). Highest tertile of occupational complexity with people was associated with higher baseline executive function (beta=0.29; 95% CI 0.18-0.40), verbal episodic memory (beta=0.12; 95% CI 0.00-0.24), and semantic memory (beta=0.23; 95% CI 0.12-0.34).DISCUSSION: In a diverse cohort, higher occupational complexity is associated with better cognition. Findings should be verified in larger cohorts.HIGHLIGHT: Few studies have examined associations of occupational complexity with cognition in diverse populations. Racial and ethnic minorities are disproportionately exposed to lower occupational complexity. Occupational complexity with data and people are associated with better cognition.
View details for DOI 10.1002/alz.13038
View details for PubMedID 37057753
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State-Level Indicators of Childhood Educational Quality and Incident Dementia in Older Black and White Adults.
JAMA neurology
2023
Abstract
Higher educational attainment is associated with reduced dementia risk, but the role of educational quality is understudied, presenting a major evidence gap, especially as it may contribute to racial inequities.To evaluate the association between state-level educational quality during childhood and dementia risk.This cohort study analyzed longitudinal data collected from January 1, 1997, through December 31, 2019 (23-year follow-up period). The sample comprised members of Kaiser Permanente Northern California (KPNC), a large integrated health care delivery system, who completed an optional survey during 1964-1972. Eligible individuals were US born; non-Hispanic Black or non-Hispanic White; aged 65 years or older as of January 1, 1996; were still alive; and did not have a dementia diagnosis or lapse in KPNC membership greater than 90 days between January 1 and December 31, 1996.Historical state-level administrative indicators of school quality (school term length, student-teacher ratio, and attendance rates) linked to participants using birth state and birth year (with a 6-year lag) and divided into tertiles using the pooled sample.Dementia diagnoses from electronic health records between 1997 and 2019 were analyzed between March 1 and August 31, 2022. The associations of educational quality with incident dementia were estimated using Cox proportional hazards regression models.Among 21 450 KPNC members who participated in the optional survey, individuals born before availability of educational quality records (n = 87) and missing educational attainment (n = 585) were excluded. The final analytic sample was 20 778 individuals (56.5% women, 43.5% men; mean [SD] age, 74.7 [6.5] years; 18.8% Black; 81.2% White; 41.0% with less than high school education). Among Black individuals, 76.2% to 86.1% (vs 20.8%-23.3% of White individuals) attended schools in states in the lowest educational quality tertiles. Highest (vs lowest) educational quality tertiles were associated with lower dementia risk (student-teacher ratio: hazard ratio [HR], 0.88 [95% CI, 0.83-0.94]; attendance rates: HR, 0.80 [95% CI, 0.73-0.88]; term length: HR, 0.79 [95% CI, 0.73-0.86]). Effect estimates did not differ by race and were not attenuated by adjustment for educational attainment.In this cohort study, lower state-average educational quality was more common among Black individuals and associated with higher dementia risk. Differential investment in high-quality education due to structural racism may contribute to dementia disparities.
View details for DOI 10.1001/jamaneurol.2022.5337
View details for PubMedID 36780143
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Mother's education and late-life disparities in memory and dementia risk among US military veterans and non-veterans
JOURNAL OF EPIDEMIOLOGY AND COMMUNITY HEALTH
2018; 72 (12): 1162-1167
View details for DOI 10.1136/jech-2018-210771
View details for Web of Science ID 000451282500015
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Mother's education and late-life disparities in memory and dementia risk among US military veterans and non-veterans.
Journal of epidemiology and community health
2018
Abstract
BACKGROUND: Adverse childhood socioeconomic status (cSES) predicts higher late-life risk of memory loss and dementia. Veterans of U.S. wars are eligible for educational and economic benefits that may offset cSES disadvantage. We test whether cSES disparities in late-life memory and dementia are smaller among veterans than non-veterans.METHODS: Data came from US-born men in the 1995-2014 biennial surveys of the Health and Retirement Study (n=7916 born 1928-1956, contributing n=38381cognitive assessments). Childhood SES was represented by maternal education. Memory and dementia risk were assessed with brief neuropsychological assessments and proxy reports. Military service (veteran/non-veteran) was evaluated as a modifier of the effect of maternal education on memory and dementia risk. We employed linear or logistic regression models to test whether military service modified the effect of maternal education on memory or dementia risk, adjusted for age, race, birthplace and childhood health.RESULTS: Low maternal education was associated with worse memory than high maternal education (beta = -0.07SD, 95% CI -0.08 to -0.05), while veterans had better memory than non-veterans (beta = 0.03SD, 95% CI 0.02 to 0.04). In interaction analyses, maternal education disparities in memory were smaller among veterans than non-veterans (difference in disparities = 0.04SD, 95% CI 0.01 to 0.08, p = 0.006). Patterns were similar for dementia risk.CONCLUSIONS: Disparities in memory by maternal education were smaller among veterans than non-veterans, suggesting military service and benefits partially offset the deleterious effects of low maternal education on late-life cognitive outcomes.
View details for PubMedID 30082424