Yan Jiang
Clinical Assistant Professor, Medicine - Gastroenterology & Hepatology
Bio
Dr. Yan Jiang is a gastroenterologist specializing in esophageal and motility disorders including gastroesophageal reflux disease (GERD), eosinophilic esophagitis, achalasia, etc. He obtained his medical degree at New York University before completing internal medicine residency and gastroenterology fellowship at Stanford. While at Stanford, Dr. Jiang also received a master's degree in clinical research and epidemiology. His main research interests are in esophageal disorders as well as dietary interventions and technological applications to GI practice.
Clinical Focus
- Gastroenterology
- Gastroesophageal Reflux
- Eosinophilic Esophagitis
- Achalasia
- Esophageal Motility Disorders
- Swallowing Disorders
- Gastrointestinal Motility
Administrative Appointments
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Director, GI Motility Laboratory, Stanford Health Care (2025 - Present)
Boards, Advisory Committees, Professional Organizations
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Clinical Practice Committee, American Foregut Society (2023 - Present)
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Educational Affairs Committee, American College of Gastroenterology (2019 - Present)
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Member, American Gastroenterology Association (2017 - Present)
Professional Education
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Medical Education: New York University School of Medicine (2015) NY
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Fellowship: Stanford University Division of Gastroenterology and Hepatology (2021) CA
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Residency: Stanford University Internal Medicine Residency CA
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MS, Stanford University, Epidemiology and Clinical Research
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Board Certification: American Board of Internal Medicine, Gastroenterology (2021)
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Gastroenterology Fellowship, Stanford University
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Internal Medicine Residency, Stanford University
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Board Certification: American Board of Internal Medicine, Internal Medicine (2018)
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MD, New York University School of Medicine
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BS, University of California, Los Angeles
All Publications
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The Impact of Intermittent Fasting on Patients With Suspected Gastroesophageal Reflux Disease.
Journal of clinical gastroenterology
2022
Abstract
GOAL: The aim was to investigate the short-term impact of time restricted feeding on patients with suspected gastroesophageal reflux disease (GERD).BACKGROUND: Lifestyle modifications are often suggested, but the role of diet in GERD is unclear. Intermittent fasting is popular in the media and has demonstrated potential benefits with weight loss and inflammatory conditions as well as alterations in gastrointestinal hormones.STUDY: Patients who were referred for 96-hour ambulatory wireless pH monitoring off proton pump inhibitor to investigate GERD symptoms were screened for eligibility. Patients were instructed to maintain their baseline diet for the first 2 days of pH monitoring and switch to an intermittent fasting regimen (16 consecutive hour fast and 8h eating window) for the second 2 days. Objective measures of reflux and GERD symptom severity were collected and analyzed.RESULTS: A total of 25 participants were analyzed. 9/25 (36%) fully adhered to the intermittent fasting regimen, with 21/25 (84%) demonstrating at least partial compliance. Mean acid exposure time on fasting days was 3.5% versus 4.3% on nonfasting days. Intermittent fasting was associated with a 0.64 reduction in acid exposure time (95% CI: -2.32, 1.05). There was a reduction in GERD symptom scores of heartburn and regurgitation during periods of intermittent fasting (14.3 vs. 9.9; difference of -4.46, 95% CI: -7.6,-1.32).CONCLUSIONS: Initial adherence to time restricted eating may be difficult for patients. There is weak statistical evidence to suggest that intermittent fasting mildly reduces acid exposure. Our data show that short-term intermittent fasting improves symptoms of both regurgitation and heartburn.
View details for DOI 10.1097/MCG.0000000000001788
View details for PubMedID 36730832
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Development and Validation of an Artificial Intelligence System to Optimize Clinician Review of Patient Records.
JAMA network open
2021; 4 (7): e2117391
Abstract
Importance: Physicians are required to work with rapidly growing amounts of medical data. Approximately 62% of time per patient is devoted to reviewing electronic health records (EHRs), with clinical data review being the most time-consuming portion.Objective: To determine whether an artificial intelligence (AI) system developed to organize and display new patient referral records would improve a clinician's ability to extract patient information compared with the current standard of care.Design, Setting, and Participants: In this prognostic study, an AI system was created to organize patient records and improve data retrieval. To evaluate the system on time and accuracy, a nonblinded, prospective study was conducted at a single academic medical center. Recruitment emails were sent to all physicians in the gastroenterology division, and 12 clinicians agreed to participate. Each of the clinicians participating in the study received 2 referral records: 1 AI-optimized patient record and 1 standard (non-AI-optimized) patient record. For each record, clinicians were asked 22 questions requiring them to search the assigned record for clinically relevant information. Clinicians reviewed records from June 1 to August 30, 2020.Main Outcomes and Measures: The time required to answer each question, along with accuracy, was measured for both records, with and without AI optimization. Participants were asked to assess overall satisfaction with the AI system, their preferred review method (AI-optimized vs standard), and other topics to assess clinical utility.Results: Twelve gastroenterology physicians/fellows completed the study. Compared with standard (non-AI-optimized) patient record review, the AI system saved first-time physician users 18% of the time used to answer the clinical questions (10.5 [95% CI, 8.5-12.6] vs 12.8 [95% CI, 9.4-16.2] minutes; P=.02). There was no significant decrease in accuracy when physicians retrieved important patient information (83.7% [95% CI, 79.3%-88.2%] with the AI-optimized vs 86.0% [95% CI, 81.8%-90.2%] without the AI-optimized record; P=.81). Survey responses from physicians were generally positive across all questions. Eleven of 12 physicians (92%) preferred the AI-optimized record review to standard review. Despite a learning curve pointed out by respondents, 11 of 12 physicians believed that the technology would save them time to assess new patient records and were interested in using this technology in their clinic.Conclusions and Relevance: In this prognostic study, an AI system helped physicians extract relevant patient information in a shorter time while maintaining high accuracy. This finding is particularly germane to the ever-increasing amounts of medical data and increased stressors on clinicians. Increased user familiarity with the AI system, along with further enhancements in the system itself, hold promise to further improve physician data extraction from large quantities of patient health records.
View details for DOI 10.1001/jamanetworkopen.2021.17391
View details for PubMedID 34297075
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Therapeutic Implications of Diet in Inflammatory Bowel Disease and Related Immune-Mediated Inflammatory Diseases.
Nutrients
2021; 13 (3)
Abstract
Despite being a focal issue to patients, the effect of diet on adult inflammatory bowel disease (IBD) remains underexplored with limited guidance. While promising clinical trials are currently underway, there is a need for further evidence-based recommendations. As such, we summarize the current evidence on various diets used in the treatment of IBD and also explore the potential applications of dietary data from related immune-mediated inflammatory diseases (IMIDs), such as rheumatoid arthritis and psoriasis, to provide additional information to inform IBD providers. To date, there have been multiple diets investigated as adjunctive therapy in IBD, but many associated studies are small, non-randomized, and not controlled. Mediterranean, vegetarian/vegan, and reduced-calorie/fasting diets have been studied and have shown some positive results in other IMIDs, which may suggest potential applicability to those with IBD, but larger, well-designed clinical trials are needed for further guidance. Gluten-free and low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP)diets do not appear to have an impact on IBD disease activity, but low FODMAP may potentially be helpful for those with concurrent functional gastrointestinal symptoms. Specific carbohydrate diets have been mainly assessed in children but show some potential in small adult studies.
View details for DOI 10.3390/nu13030890
View details for PubMedID 33801883
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New Developments in the Diagnosis and Management of Gastroesophageal Reflux.
Current treatment options in gastroenterology
2020
Abstract
PURPOSE OF REVIEW: To examine recent key developments in the pathophysiology, diagnosis, and treatment of gastroesophageal reflux disease (GERD).RECENT FINDINGS: Newer research has suggested cytokine-mediated inflammation may play a role in the physiology of GERD, implying that the underlying mechanism may not be entirely related to chemical damage due to acid. Aided by novel technologies, diagnostic testing is also moving toward elucidating individual mechanisms and better defining specific GERD phenotypes with the goal of providing directed therapy. This is especially important in current times given the increase in coverage of adverse events reportedly linked to long-term proton pump inhibitor use. As patients are looking for potential alternatives, we highlight the key recent updates in pathophysiology and understanding of GERD and current medical and endoscopic/surgical options and explore the exciting treatments in the pipeline.
View details for DOI 10.1007/s11938-020-00275-1
View details for PubMedID 32072470
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The high resource impact of reformatting requirements for scientific papers.
PloS one
2019; 14 (10): e0223976
Abstract
Most research manuscripts are not accepted for publication on first submission. A major part of the resubmission process is reformatting to another journal's specific requirements, a process separate from revising the scientific content. There has been little research to understand the magnitude of the burden imposed by the current resubmission process.We analyzed original research article submission requirements from twelve randomly selected journals in each of eight scientific and clinical focus areas from the InCites Journal Citation Reports database. From the 96 journals selected, we randomly identified three recently published manuscripts and sent surveys to those first and/or corresponding authors (288 total) to solicit information on time spent reformatting resubmissions and opinions on the process.There was significant variation in manuscript submission requirements for journals within the same scientific focus and only 4% of journals offered a fully format-free initial submission. Of 203 authors responding (71.5% response rate), only 11.8% expressed satisfaction with the resubmission process and 91% desired reforming the current system. Time spent on reformatting delays most publications by at least two weeks and by over three months in about 20% of manuscripts. The effort to comply with submission requirements has significant global economic burden, estimated at over $1.1 billion dollars annually when accounting for a research team's time.We demonstrate that there is significant resource utilization associated with resubmitting manuscripts, heretofore not properly quantified. The vast majority of authors are not satisfied with the current process. Addressing these issues by reconciling reformatting requirements among journals or adopting a universal format-free initial submission policy would help resolve a major subject for the scientific research community and provide more efficient dissemination of findings.
View details for DOI 10.1371/journal.pone.0223976
View details for PubMedID 31665156
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Distal contractile integral and other key predictors of mean nocturnal baseline impedance: The role of esophageal peristaltic vigor in mucosal permeability.
Neurogastroenterology and motility
2024: e14937
Abstract
Understanding the relationship between distal contractile integral (DCI) and mean nocturnal baseline impedance (MNBI) could shed light on new diagnostic and treatment strategies, specifically concerning nocturnal reflux. This study aimed to assess this relationship to enhance our comprehension of the interplay between esophageal contractility and mucosal permeability.We identified adult patients who had high resolution esophageal manometry and pH-impedance tests performed within a 30-day period between December 2018 and March 2022. A random forest model was used to identify significant predictors of MNBI, assisting with variable selection for a following regression analysis. Subsequently, both univariable and multivariable regression models were utilized to measure the association between predictors and MNBI.Our study included 188 patients, primarily referred for testing due to reflux. The most common motility diagnoses were normal (62%) followed by possible esophagogastric junction outflow obstruction (22%). The mean DCI was 2020 mmHg∙s∙cm and MNBI was 3.05 kΩ. The random forest model identified 12 significant predictors for MNBI, key variables being acid exposure time (AET), total proximal reflux events, intraabdominal lower esophageal sphincter length, hiatal hernia presence, and DCI. Subsequent multivariable regression analyses demonstrated log AET (β = -0.69, p = <0.001), total proximal reflux events (β = -0.16, p = 0.008), hiatal hernia presence (β = -0.82, p = 0.014), log DCI (β = 1.26, p < 0.001), and age (β = -0.13, p = 0.036) as being significantly associated with MNBI.DCI is a key manometric predictor of MNBI emphasizing the role of manometry in detecting reflux risk and the need for its consideration in reflux management.
View details for DOI 10.1111/nmo.14937
View details for PubMedID 39370633
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Functional lumen imaging probe use in a high-volume practice: Practical and technical implications.
World journal of gastrointestinal endoscopy
2024; 16 (7): 396-405
Abstract
The functional lumen imaging probe (FLIP) is a Food and Drug Administration approved tool to aid the diagnosis and management of esophageal disorders. However, widespread adoption of FLIP remains limited and its utility in high-volume practices remains unclear.To analyze large sample data on clinical use of FLIP and provide insight on several technical aspects when performing FLIP.We conducted a retrospective comparative and descriptive analysis of FLIP procedures performed by a single provider at an academic medical center. There was a total of 398 FLIP procedures identified. Patient medical records were reviewed and data regarding demographics and procedural details were collected. Statistical tests, including chi-squared, t-test, and multivariable logistic and linear regression, were performed.There was an increase in FLIP cases with each successive time period of 13 months (n = 68, 146, 184, respectively) with notable rises specifically for indications of dysphagia and gastroesophageal reflux disease. There was a shift toward use of the longer FLIP balloon catheter for diagnostic purposes (overall 70.4% vs 29.6%, P < 0.01). Many cases (42.8%) were performed in conjunction with other diagnostics/interventions, such as dilation and wireless pH probe placement. Procedures were nearly equally performed with anesthesia vs moderate sedation (51.4% anesthesia), with no major complications. Patients who had anesthesia were less likely to have recurrent antegrade contractions [odds ratio (OR) = 0.4, 95%CI: 0.3-0.8] and were also more likely to have absent contractility (OR = 2.4, 95%CI: 1.3-4.4).FLIP cases have increased in our practice with expanding indications for its use. Given limited normative data, providers should be aware of several potential technical issues, including the possible impact of sedation choice when assessing esophageal motility patterns.
View details for DOI 10.4253/wjge.v16.i7.396
View details for PubMedID 39072247
View details for PubMedCentralID PMC11271713
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Electroceuticals for Neurogastroenterology and Motility Disorders.
Current gastroenterology reports
2023
Abstract
To provide an updated overview on use of electrostimulation in gastrointestinal motility disorders and obesity, with a focus on gastric electrical stimulation, vagal nerve stimulation and sacral nerve stimulation.Recent studies on gastric electrical stimulation for chronic vomiting showed a decrease in frequency of vomiting, but without significant improvement in quality of life. Percutaneous vagal nerve stimulation shows some promise for both symptoms of gastroparesis and IBS. Sacral nerve stimulation does not appear effective for constipation. Studies of electroceuticals for treatment of obesity have quite varied results with less clinical penetrance of the technology. Results of studies on the efficacy of electroceuticals have been variable depending on pathology but this area remains promising. Improved mechanistic understanding, technology and more controlled trials will be helpful to establish a clearer role for electrostimulation in treatment of various GI disorders.
View details for DOI 10.1007/s11894-023-00866-9
View details for PubMedID 36867326
View details for PubMedCentralID 8186669
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The Effects of Intermittent Fasting on Gastroesophageal Reflux Disease
LIPPINCOTT WILLIAMS & WILKINS. 2021: S214
View details for Web of Science ID 000717526100484
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Efficacy of Dietary Supplements in Inflammatory Bowel Disease and Related Autoimmune Diseases.
Nutrients
2020; 12 (7)
Abstract
The microbiome is an important contributor to a variety of fundamental aspects of human health, including host metabolism, infection, and the immune response. Gut dysbiosis has been identified as a contributor to the errant immune response in a variety of immune-mediated inflammatory diseases (IMIDs), such as inflammatory bowel disease (IBD), rheumatoid arthritis (RA), and psoriatic disease (psoriasis and psoriatic arthritis). Given this, probiotics and prebiotics have been investigated as therapeutic options in these disease states. In our review, we highlight the current evidence on prebiotics and probiotics as well as other supplements (such as fish oils, vitamin D, and curcumin) as therapies for IBD. Recommendations, however, regarding the specific use of such supplements in IBD have been lacking, particularly from professional societies, often due to study limitations related to small sample sizes and design heterogeneity. Hence, we additionally examine the literature on the use of prebiotics, probiotics, and other supplements in related IMIDs, namely RA and psoriasis/psoriatic arthritis, as these diseases share many approved therapeutic options with IBD. Based on these combined findings, we offer additional evidence that may help guide clinicians in their treatment of patients with IBD (and other IMIDs) and provide recommendations on potential next steps in therapeutic research in this area.
View details for DOI 10.3390/nu12072156
View details for PubMedID 32698454
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Use of Tumor Necrosis Factor Alpha Inhibitors for Inflammatory Bowel Disease Patients with Concurrent Heart Failure.
Digestive diseases and sciences
2017; 62 (6): 1597-1606
Abstract
Prescribing information for tumor necrosis factor alpha (TNFα) inhibitors, a mainstay of treatment for moderate to severe inflammatory bowel disease (IBD), instructs cautious use in those with heart failure (HF). However, the limited data behind these warnings are inconclusive and should be weighed against mounting evidence demonstrating worse cardiac outcomes in active IBD.To assess whether TNFα inhibitor use is reduced in patients with IBD and HF by analyzing physician practice and prescription patterns.Using a Stanford University database, we queried TNFα inhibitor prescriptions in 8905 patients with an ICD-9 diagnosis of Crohn's disease or ulcerative colitis. Detailed chart review analysis was done for patients with a concurrent diagnosis of HF who were prescribed anti-TNFα agents. In addition, we collected survey data from 25 gastroenterologists on their usage of these drugs for patients with IBD and HF.TNFα inhibitors were prescribed to 10/455 (2.2%) IBD patients with HF compared to 1265/8450 (15.0%) in IBD patients without HF (p < 0.0001). Of those ten with HF prescribed TNFα inhibitors, only one had it discontinued because of HF exacerbation while on drug. Survey data indicated few (5/25) providers do not actively avoid TNFα inhibitors for those with HF.IBD patients with HF are prescribed significantly less TNFα inhibitors than those without HF. The majority of providers are either uncertain about or actively avoid use of anti-TNFα medications for those with HF. The risks and benefits of anti-TNFα use in HF patients must be investigated further.
View details for DOI 10.1007/s10620-017-4574-2
View details for PubMedID 28417241
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Long-term outcomes after biliopancreatic diversion with and without duodenal switch: 2-, 5-, and 10-year data
SURGERY FOR OBESITY AND RELATED DISEASES
2016; 12 (9): 1697–1705
Abstract
There are minimal long-term data on biliopancreatic diversion (BPD) with or without duodenal switch (BPD/DS).To investigate the long-term weight loss, co-morbidity remission, complications, and quality of life after BPD and BPD/DS.An academic, university hospital in the United States.We conducted a retrospective review of patients who underwent BPD or BPD/DS between 1999 and 2011. Outcomes included weight loss measures at 2, 5, and 10-15 years postoperatively; co-morbidity remission; long-term complications; nutritional deficiencies; and patient satisfaction.One hundred patients underwent BPD (34%) or BPD/DS (64%). Mean preoperative body mass index (BMI) was 50.2 kg/m2. Mean follow up was 8.2 years (range: 1-15 yr) with 72% of eligible patients in active follow up at 10-15 years postoperatively. Excess weight loss (EWL) was 65.1% at 2 years, 63.8% at 5 years, and 67.9% at 10-15 years. Approximately 10% higher %EWL was achieved for those with preoperative BMI<50 kg/m2 versus≥50 kg/m2 and patients who underwent BPD/DS versus BPD. Although co-morbidities improved, 37% of patients developed long-term complications requiring surgery. There were no 30-day mortalities; however, there was one mortality from severe malnutrition. Nutritional deficiencies in fat-soluble vitamins, anemia, and secondary hyperparathyroidism were common. Overall, 94% of patients reported satisfaction with their choice of surgery.This clinical experience supports the long-term positive safety profile and efficacy of BPD and BPD/DS at a single U.S. center. Higher levels of excess weight loss are achieved by patients with a lower preoperative BMI and BPD/DS. Although nutritional deficiencies and postoperative complications are common, patient satisfaction remains high.
View details for DOI 10.1016/j.soard.2016.03.006
View details for Web of Science ID 000391159800011
View details for PubMedID 27425842
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Can aminotransferase-to-platelet ratio index and other non-invasive markers effectively reduce liver biopsies for renal transplant evaluation of hepatitis C virus-positive patients?
NEPHROLOGY DIALYSIS TRANSPLANTATION
2014; 29 (6): 1247–52
Abstract
Advanced fibrosis or cirrhosis is still regarded as a contraindication for kidney transplantation alone by most centers. The value of aminotransferase to platelet ratio index (APRI) and other non-invasive markers has been less studied in hepatitis C virus (HCV)-positive patients with concurrent end-stage renal disease to predict hepatic fibrosis. Can these be used to effectively decrease the number of biopsies done in these patients being evaluated for transplantation?Our study population included 255 patients with liver biopsy data. All patient information was collected and reviewed from medical records. The diagnostic accuracy of the predictive models was analyzed by calculating sensitivity, specificity, positive predictive value and negative predictive value.The variables associated with F3-F4 were aspartate aminotransferase (P = 0.007), bilirubin (P ≤ 0.001), platelet count (P = 0.01) and APRI (P ≤ 0.001). The use of any one laboratory abnormality to predict liver biopsy scores did not show high positive predictive values (22.6-72.7%). Having abnormal liver findings or cirrhosis on imaging was associated with high specificities (92.0-97.8%) but low sensitivities (31.4-42.9%). Using APRI levels of ≥0.40 and ≤0.95 as an indication for liver biopsy, 50% of patients with F3-F4 would have correctly avoided having a biopsy. However, 33% of patients with F3-F4 would have been mislabeled and not be indicated for biopsy.Our data suggest that there may not currently be a simple and sufficiently accurate non-invasive test to replace liver biopsy in renal transplant workup for HCV-positive patients. The risks outweigh the benefits when it comes to using non-invasive markers like the APRI.
View details for DOI 10.1093/ndt/gft485
View details for Web of Science ID 000337079600024
View details for PubMedID 24353319
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Risk factors for development of new-onset diabetes mellitus after transplant in adult lung transplant recipients
CLINICAL TRANSPLANTATION
2011; 25 (6): 885–91
Abstract
The objectives of this study are to examine the incidence of new-onset diabetes mellitus after transplant (NODAT) and to identify its risk factors in adult lung transplant recipients using the Organ Procurement and Transplant Network/United Network of Organ Sharing database. Between July 2004 and December 2007, a total of 3540 adults (≥18 yr old) received their first single- or double-lung transplant alone and had at least one follow-up report of post-transplant diabetic status. Among these, 2991 recipients were identified as not having diabetes mellitus (DM) pre-transplant. Risk factors for NODAT were examined. DM was newly reported in 33.4% of the 2991 recipients over the median follow-up time of 670 d. Significant independent risk factors for the development of NODAT included male gender (HR = 1.15), recipient age ≥50 (1.46), African American (1.39), higher body mass index (1.51 for ≥30 vs. 18-25), cystic fibrosis (3.30), and tacrolimus use at discharge (1.67). NODAT occurred in a third of adult lung transplant recipients during the median follow-up period. Some of the risk factors for NODAT after lung transplant are similar to those reported in other solid-organ transplants. Cystic fibrosis is a strong risk factor for development of NODAT after lung transplant.
View details for DOI 10.1111/j.1399-0012.2010.01383.x
View details for Web of Science ID 000297929500027
View details for PubMedID 21175848
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Risk Factors for Development of New-Onset Diabetes Mellitus in Adult Heart Transplant Recipients
TRANSPLANTATION
2010; 89 (12): 1526–32
Abstract
The objectives of this study are to examine the incidence of new-onset diabetes mellitus (NODM) and to identify its risk factors in adult heart recipients using the Organ Procurement and Transplant Network/United Network of Organ Sharing database.Between July 2004 and December 2007, 4972 adults (aged 18 years or older) received their first heart transplant alone, and had at least one follow-up report of posttransplant diabetic status. Among these, 3763 recipients were identified as not having diabetes mellitus pretransplant. Risk factors for NODM were examined using multivariate Cox regression analysis using the time to NODM diagnosis as a time-varying endpoint.NODM was reported in 1075 (28.6%) of the 3763 recipients without pretransplant diabetes (median follow-up time, 713 days). Independent risk factors for development of NODM included older age (hazard ratio=1.20 for age >or=50 years vs. <50, P=0. 01), non-white race (0.70 for white vs. non-white, P<0.0001), higher body mass index (BMI) (1.55 for BMI >or=25 vs. <25, P<0.0001), ischemic heart disease (1.24, P<0.0001), recipient cytomegalovirus positivity (1.16, P=0.003), tobacco use (1.16, P=0.02), tacrolimus use at discharge (1.85 for tacrolimus vs. cyclosporine use, P<0.0001), and use of steroids at discharge (2.59 for steroid use vs. none, P=0.008).NODM is common and occurs in more than a quarter of heart recipients during the median follow-up period of 2 years. Risk factors for NODM after heart transplant are similar to those reported in other solid organ transplants. Some of these factors, such as BMI and immunosuppressive regimen, are potentially modifiable.
View details for DOI 10.1097/TP.0b013e3181dd6bd9
View details for Web of Science ID 000279347800016
View details for PubMedID 20431437