Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where John R. Pender is active.

Publication


Featured researches published by John R. Pender.


JAMA | 2013

Weight Change and Health Outcomes at 3 Years After Bariatric Surgery Among Individuals With Severe Obesity

Anita P. Courcoulas; Nicholas J. Christian; Steven H. Belle; Paul D. Berk; David R. Flum; Luis Garcia; Mary Horlick; Melissa A. Kalarchian; Wendy C. King; James E. Mitchell; Emma J. Patterson; John R. Pender; Alfons Pomp; Walter J. Pories; Richard C. Thirlby; Susan Z. Yanovski; Bruce M. Wolfe

IMPORTANCE Severe obesity (body mass index [BMI] ≥35) is associated with a broad range of health risks. Bariatric surgery induces weight loss and short-term health improvements, but little is known about long-term outcomes of these operations. OBJECTIVE To report 3-year change in weight and select health parameters after common bariatric surgical procedures. DESIGN AND SETTING The Longitudinal Assessment of Bariatric Surgery (LABS) Consortium is a multicenter observational cohort study at 10 US hospitals in 6 geographically diverse clinical centers. PARTICIPANTS AND EXPOSURE: Adults undergoing first-time bariatric surgical procedures as part of routine clinical care by participating surgeons were recruited between 2006 and 2009 and followed up until September 2012. Participants completed research assessments prior to surgery and 6 months, 12 months, and then annually after surgery. MAIN OUTCOMES AND MEASURES Three years after Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB), we assessed percent weight change from baseline and the percentage of participants with diabetes achieving hemoglobin A1c levels less than 6.5% or fasting plasma glucose values less than 126 mg/dL without pharmacologic therapy. Dyslipidemia and hypertension resolution at 3 years was also assessed. RESULTS At baseline, participants (N = 2458) were 18 to 78 years old, 79% were women, median BMI was 45.9 (IQR, 41.7-51.5), and median weight was 129 kg (IQR, 115-147). For their first bariatric surgical procedure, 1738 participants underwent RYGB, 610 LAGB, and 110 other procedures. At baseline, 774 (33%) had diabetes, 1252 (63%) dyslipidemia, and 1601 (68%) hypertension. Three years after surgery, median actual weight loss for RYGB participants was 41 kg (IQR, 31-52), corresponding to a percentage of baseline weight lost of 31.5% (IQR, 24.6%-38.4%). For LAGB participants, actual weight loss was 20 kg (IQR, 10-29), corresponding to 15.9% (IQR, 7.9%-23.0%). The majority of weight loss was evident 1 year after surgery for both procedures. Five distinct weight change trajectory groups were identified for each procedure. Among participants who had diabetes at baseline, 216 RYGB participants (67.5%) and 28 LAGB participants (28.6%) experienced partial remission at 3 years. The incidence of diabetes was 0.9% after RYGB and 3.2% after LAGB. Dyslipidemia resolved in 237 RYGB participants (61.9%) and 39 LAGB participants (27.1%); remission of hypertension occurred in 269 RYGB participants (38.2%) and 43 LAGB participants (17.4%). CONCLUSIONS AND RELEVANCE Among participants with severe obesity, there was substantial weight loss 3 years after bariatric surgery, with the majority experiencing maximum weight change during the first year. However, there was variability in the amount and trajectories of weight loss and in diabetes, blood pressure, and lipid outcomes. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00465829.


The Journal of Clinical Endocrinology and Metabolism | 2008

Mechanism for Improved Insulin Sensitivity after Gastric Bypass Surgery

Benjamin T. Bikman; Donghai Zheng; Walter J. Pories; William H. Chapman; John R. Pender; Rita C. Bowden; Melissa A. Reed; Ronald N. Cortright; Edward B. Tapscott; Joseph A. Houmard; Charles J. Tanner; Jihyun Lee; G. Lynis Dohm

CONTEXT Surgical treatments of obesity have been shown to induce rapid and prolonged improvements in insulin sensitivity. OBJECTIVE The aim of the study was to investigate the effects of gastric bypass surgery and the mechanisms that explain the improvement in insulin sensitivity. DESIGN We performed a cross-sectional, nonrandomized, controlled study. SETTING This study was conducted jointly between the Departments of Exercise Science and Physiology at East Carolina University in Greenville, North Carolina. SUBJECTS Subjects were recruited into four groups: 1) lean [body mass index (BMI) < 25 kg/m(2); n = 93]; 2) weight-matched (BMI = 25 to 35 kg/m(2); n = 310); 3) morbidly obese (BMI > 35 kg/m(2); n = 43); and 4) postsurgery patients (BMI approximately 30 kg/m(2); n = 40). Postsurgery patients were weight stable 1 yr after surgery. MAIN OUTCOME MEASURES Whole-body insulin sensitivity, muscle glucose transport, and muscle insulin signaling were assessed. RESULTS Postsurgery subjects had insulin sensitivity index values that were similar to the lean and higher than morbidly obese and weight-matched control subjects. Glucose transport was higher in the postsurgery vs. morbidly obese and weight-matched groups. IRS1-pSer(312) in the postsurgery group was lower than morbidly obese and weight-matched groups. Inhibitor kappaBalpha was higher in the postsurgery vs. the morbidly obese and weight-matched controls, indicating reduced inhibitor of kappaB kinase beta activity. CONCLUSIONS Insulin sensitivity and glucose transport are greater in the postsurgery patients than predicted from the weight-matched group, suggesting that improved insulin sensitivity after bypass is due to something other than, or in addition to, weight loss. Improved insulin sensitivity is related to reduced inhibitor of kappaB kinase beta activity and enhanced insulin signaling in muscle.


Surgery for Obesity and Related Diseases | 2012

Pre- to postoperative changes in physical activity: report from the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2)

Wendy C. King; Jesse Y. Hsu; Steven H. Belle; Anita P. Courcoulas; George M. Eid; David R. Flum; James E. Mitchell; John R. Pender; Mark D. Smith; Kristine J. Steffen; Bruce M. Wolfe

BACKGROUND Numerous studies have reported that bariatric surgery patients report more physical activity (PA) after surgery than before; however, the quality of the PA assessment has been questionable. METHODS The longitudinal assessment of bariatric surgery-2 is a 10-center longitudinal study of adults undergoing bariatric surgery. Of 2458 participants, 455 were given an activity monitor, which records the steps per minute, and an exercise diary before and 1 year after surgery. The mean number of steps/d, active min/d, and high-cadence min/wk were calculated for 310 participants who wore the monitor ≥10 hr/d for ≥3 days at both evaluations. Pre- and postoperative PA were compared for differences using the Wilcoxon signed-rank test. Generalized estimating equations were used to identify independent preoperative predictors of postoperative PA. RESULTS PA increased significantly (P < .0001) from before to after surgery for all PA measures. The median values before and after surgery were 7563 and 8788 steps/d, 309 and 340 active min/d, and 72 and 112 high-cadence min/wk, respectively. However, depending on the PA measure, 24-29% of participants were ≥5% less active postoperatively than preoperatively. Controlling for surgical procedure, gender, age, and body mass index, more PA preoperatively independently predicted for more PA postoperatively (P < .0001, for all PA measures). Less pain, not having asthma, and the self-report of increasing PA as a weight loss strategy preoperatively also independently predicted for more high-cadence min/wk postoperatively (P < .05). CONCLUSIONS The majority of adults increase their PA level after bariatric surgery. However, most remain insufficiently active, and some become less active. Increasing PA, addressing pain, and treating asthma before surgery might have a positive effect on postoperative PA.


International Journal of Eating Disorders | 2015

Eating Behavior and Eating Disorders in Adults Before Bariatric Surgery

James E. Mitchell; Wendy C. King; Anita P. Courcoulas; George F. Dakin; Katherine A. Elder; Scott G. Engel; David R. Flum; Melissa A. Kalarchian; Saurabh Khandelwal; John R. Pender; Walter J. Pories; Bruce M. Wolfe

OBJECTIVE To describe eating patterns, prevalence of problematic eating behaviors, and determine factors associated with binge eating disorder (BED), before bariatric surgery. METHOD Before surgery, 2,266 participants (median age 46 years; 78.6% female; 86.9% white; median body mass index 45.9 kg/m(2) ) of the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) study completed eating behavior survey items in the self-administered LABS-2 Behavior form. Other measures included the Alcohol Use Disorder Identification Test, the LABS-2 Psychiatric and Emotional Test Survey, the Beck Depression Inventory, the Interpersonal Support Evaluation List-12, the Short Form-36 Health Survey, and Impact of Weight Quality of Life-Lite Survey. RESULTS The majority (92.1%) of participants reported eating dinner regularly, whereas just over half (54.0%) reported eating breakfast regularly. Half of the participants reported eating at least four meals/week at restaurants; two meals/week were fast food. Loss of control eating was reported by 43.4%, night eating syndrome by 17.7%; 15.7% satisfied criteria for binge eating disorder (BED), 2% for bulimia nervosa. Factors that independently increased the odds of BED were being a college graduate, eating more times per day, taking medication for psychiatric or emotional problems, and having symptoms of alcohol use disorder, lower self-esteem and greater depressive symptoms. DISCUSSION Before undergoing bariatric surgery a substantial proportion of patients report problematic eating behaviors. Several factors associated with BED were identified, most suggesting other mental health problems, including higher levels of depressive symptomotology. The strengths of this study include the large sample size, the multi-center design and use of standardized assessment practices.


Obesity | 2014

Course of depressive symptoms and treatment in the longitudinal assessment of bariatric surgery (LABS-2) study.

James E. Mitchell; Wendy C. King; Jia Yuh Chen; Michael J. Devlin; David R. Flum; Luis Garcia; William Inabet; John R. Pender; Melissa A. Kalarchian; Saurabh Khandelwal; Marsha D. Marcus; Beth Schrope; Gladys Strain; Bruce M. Wolfe; Susan Z. Yanovski

To examine changes in depressive symptoms and treatment in the first 3 years following bariatric surgery.


Fertility and Sterility | 2010

Reproductive Health of Women Electing Bariatric Surgery

Gabriella G. Gosman; Wendy C. King; Beth Schrope; Kristine J. Steffen; Gladys Strain; Anita P. Courcoulas; David R. Flum; John R. Pender; Hyagriv N. Simhan

OBJECTIVE To describe the reproductive health history and characteristics of women having bariatric surgery and to determine whether this differs by age of onset of obesity. DESIGN Retrospective and cross-sectional analyses of self-reported survey data. SETTING Six sites of the Longitudinal Assessment of Bariatric Surgery-2 study. PATIENT(S) The study included 1,538 females having bariatric surgery. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Reported polycystic ovary syndrome (PCOS), pregnancy and fertility history, contraceptive use, and plans for pregnancies. RESULT(S) Mean age was 44.8 years (range, 18-78 years); mean body mass index was 47.2 kg/m2 (range, 33.8-87.3 kg/m2). PCOS had been diagnosed by a health care provider in 13.1% of subjects. Of women who had tried to conceive, 41.9% experienced infertility and 61.4% had a live birth after experiencing infertility. In the whole group, prior live birth was reported by 72.5%. Women who were obese by 18 years old were more likely to report PCOS and infertility and less likely to have ever been pregnant, compared with women who became obese later in life. Future pregnancy was important to 30.3% of women younger than 45 years, whereas 48.6% did not plan to become pregnant in the future. In the year before surgery, 51.8% used contraception. CONCLUSION(S) Self-reporting of obesity by age 18 appears to be related to reproductive morbidity. Women undergoing bariatric surgery have important reproductive health care needs, including reliable contraception and counseling about plans for postoperative pregnancy.


Surgery for Obesity and Related Diseases | 2013

Baseline characteristics of participants in the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) study

Steven H. Belle; Paul D. Berk; William H. Chapman; Nicholas J. Christian; Anita P. Courcoulas; Greg Dakin; David R. Flum; Mary Horlick; Wendy C. King; Carol McCloskey; James E. Mitchell; Emma J. Patterson; John R. Pender; Kristine J. Steffen; Richard C. Thirlby; Bruce M. Wolfe; Susan Z. Yanovski

Baseline characteristics of participants in the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) study Steven H. Belle, Ph.D., M.Sc.Hyg.*, Paul D. Berk, M.D., William H. Chapman, M.D., Nicholas J. Christian, Ph.D., Anita P. Courcoulas, M.D., M.P.H., F.A.C.S., Greg F. Dakin, M.D., David R. Flum, M.D., M.P.H., F.A.C.S., Mary Horlick, M.D., Wendy C. King, Ph.D., Carol A. McCloskey, M.D., James E. Mitchell, M.D., Emma J. Patterson, M.D., John R. Pender, M.D., Kristine J. Steffen, Pharm.D., Ph.D., Richard C. Thirlby, M.D., Bruce M. Wolfe, M.D., F.A.C.S., Susan Z. Yanovski, M.D., for The LABS Consortium University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania Columbia University Medical Center, New York, New York East Carolina University, Greenville, North Carolina University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania Weill Cornell University Medical Center, New York, New York University of Washington, Seattle, Washington National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland Neuropsychiatric Research Institute, Fargo, North Dakota Legacy Good Samaritan Hospital, Portland, Oregon Virginia Mason Medical Center, Seattle, Washington Oregon Health and Science University, Portland, Oregon Received January 23, 2013; accepted January 29, 2013


Pediatrics | 2013

The Effect of Obesity in Adolescence on Adult Health Status

Thomas H. Inge; Wendy C. King; Todd M. Jenkins; Anita P. Courcoulas; Mark Mitsnefes; David R. Flum; Bruce M. Wolfe; Alfons Pomp; Greg Dakin; Saurabh Khandelwal; Meg H. Zeller; Mary Horlick; John R. Pender; Jia-Yuh Chen; Stephen R. Daniels

OBJECTIVE: To test the hypothesis that adolescent obesity would be associated with greater risks of adverse health in severely obese adults. METHODS: Before weight loss surgery, adult participants in the Longitudinal Assessment of Bariatric Surgery-2 underwent detailed anthropometric and comorbidity assessment. Weight status at age 18 was retrospectively determined. Participants who were ≥80% certain of recalled height and weight at age 18 (1502 of 2308) were included. Log binomial regression was used to evaluate whether weight status at age 18 was independently associated with risk of comorbid conditions at time of surgery controlling for potential confounders. RESULTS: Median age and adult body mass index (BMI) were 47 years and 46, respectively. At age 18, 42% of subjects were healthy weight, 29% overweight, 16% class 1 obese, and 13% class ≥2 obese. Compared with healthy weight at age 18, class ≥2 obesity at age 18 independently increased the risk of lower-extremity venous edema with skin manifestations by 435% (P < .0001), severe walking limitation by 321% (P < .0001), abnormal kidney function by 302% (P < .0001), polycystic ovary syndrome by 74% (P = .03), asthma by 48% (P = .01), diabetes by 42% (P < .01), obstructive sleep apnea by 25% (P < .01), and hypertension (by varying degrees based on age and gender). Conversely, the associated risk of hyperlipidemia was reduced by 61% (P < .01). CONCLUSIONS: Severe obesity at age 18 was independently associated with increased risk of several comorbid conditions in adults undergoing bariatric surgery.


Surgery for Obesity and Related Diseases | 2010

Comparison of 30-day outcomes after non-LapBand primary and revisional bariatric surgical procedures from the Longitudinal Assessment of Bariatric Surgery study

William B. Inabnet; Steven H. Belle; Marc Bessler; Anita P. Courcoulas; Patchen Dellinger; Luis Garcia; James E. Mitchell; Brant K. Oelschlager; Robert W. O'Rourke; John R. Pender; Alfons Pomp; Walter J. Pories; Ramesh K. Ramanathan; Abdus S. Wahed; Bruce M. Wolfe

BACKGROUND The goals were to compare the morbidity and mortality between primary and revisional bariatric surgery and to identify the clinical predictors of adverse outcomes among patients undergoing revisional surgery in the Longitudinal Assessment of Bariatric Surgery consortium. The study was multi-institutional at university hospitals in the United States. METHODS Data from the LABS-1 (safety) cohort were analyzed, excluding primary gastric banding patients. A total of 3802 LABS-1 patients were included: 3577 who underwent primary surgery and 225 who underwent revisional surgery. The demographic, clinical, operative, and 30-day outcome data were compared between the 2 groups. A nonlinear mixed effects logit model was used to identify independent risk factors for adverse outcomes (death, deep vein thrombosis, pulmonary embolism, reintubation, reoperation, or discharge after 30 days). RESULTS Compared with those undergoing revisional surgery, the primary surgery patients were younger (median age 44 versus 49 years, P <.0001) and more likely to be male (20.5% versus 12.7%, P = .006) and heavier (median body mass index 47.3 versus 41.2 kg/m(2), P <.0001) and to have more co-morbidities (P <.0001), including hypertension (56.0% versus 46.0%, P = .0044), diabetes (35.7% versus 20.0%, P <.0001), and sleep apnea (50.3% versus 27.2%, P <.0001). The operative time for the revisional procedures was longer (median 181 versus 135 min, P <.0001) and associated with greater blood loss (median 100 versus <50 mL, P <.0001). Adverse outcomes were more likely after revisional surgery (15.1% versus 5.3%, P <.0001, odds ratio 2.4, 95% confidence interval 1.6-3.6). After adjusting for patient characteristics previously shown to be associated with adverse outcomes, this difference remained statistically significant (odds ratio 2.3, 95% confidence interval 1.5-3.8). The 30-day mortality rate was similar in the 2 groups (.4%). CONCLUSION Revisional surgery was performed without substantial mortality but with a greater incidence of adverse outcomes than was primary bariatric surgery.


Diabetes Care | 2016

Type 2 Diabetes Remission Rates After Laparoscopic Gastric Bypass and Gastric Banding: Results of the Longitudinal Assessment of Bariatric Surgery Study

Jonathan Q. Purnell; Faith Selzer; Abdus S. Wahed; John R. Pender; Walter J. Pories; Alfons Pomp; Greg Dakin; James E. Mitchell; Luis Garcia; Myrlene A. Staten; Carol McCloskey; David E. Cummings; David R. Flum; Anita P. Courcoulas; Bruce M. Wolfe

OBJECTIVE The goals of this study were to determine baseline and postbariatric surgical characteristics associated with type 2 diabetes remission and if, after controlling for differences in weight loss, diabetes remission was greater after Roux-en-Y gastric bypass (RYGBP) than laparoscopic gastric banding (LAGB). RESEARCH DESIGN AND METHODS An observational cohort of obese participants was studied using generalized linear mixed models to examine the associations of bariatric surgery type and diabetes remission rates for up to 3 years. Of 2,458 obese participants enrolled, 1,868 (76%) had complete data to assess diabetes status at both baseline and at least one follow-up visit. Of these, 627 participants (34%) were classified with diabetes: 466 underwent RYGBP and 140 underwent LAGB. RESULTS After 3 years, 68.7% of RYGBP and 30.2% of LAGB participants were in diabetes remission. Baseline factors associated with diabetes remission included a lower weight for LAGB, greater fasting C-peptide, lower leptin-to-fat mass ratio for RYGBP, and a lower hemoglobin A1c without need for insulin for both procedures. After both procedures, greater postsurgical weight loss was associated with remission. However, even after controlling for differences in amount of weight lost, relative diabetes remission rates remained nearly twofold higher after RYGBP than LAGB. CONCLUSIONS Diabetes remission up to 3 years after RYGBP and LAGB was proportionally higher with increasing postsurgical weight loss. However, the nearly twofold greater weight loss–adjusted likelihood of diabetes remission in subjects undergoing RYGBP than LAGB suggests unique mechanisms contributing to improved glucose metabolism beyond weight loss after RYGBP.

Collaboration


Dive into the John R. Pender's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

David R. Flum

University of Washington

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Wendy C. King

University of Pittsburgh

View shared research outputs
Top Co-Authors

Avatar

James E. Mitchell

University of North Dakota

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Kristine J. Steffen

North Dakota State University

View shared research outputs
Researchain Logo
Decentralizing Knowledge