title: Predictors of weight regain in patients who underwent Roux-en-Y gastric bypass surgery.
abstract: BACKGROUND
  Roux-en-Y gastric bypass (RYGB) is a highly effective treatment for obesity and results in long-term weight loss and resolution of co-morbidities. However, weight regain may occur as soon as 1-2 years after surgery.
  
  
  OBJECTIVE
  This retrospective study aimed to investigate the prevalence of weight regain and possible preoperative predictors of this phenomenon after RYGB.
  
  
  METHODS
  An academic medical center in the United States.
  
  
  METHODS
  A total of 1426 obese patients (15.8% male) who underwent RYGB during January 2000 to 2012 and had at least a 2-year follow-up were reviewed. We included only patients who were initially successful, having achieved at least 50% excess weight loss at 1 year postoperatively. Patients were then categorized into either the weight regain group (WR) or sustained weight loss (SWL) group based upon whether they gained≥15% of their 1-year postoperative weight.
  
  
  RESULTS
  Weight regain was observed in 244 patients (17.1%). Preoperative body mass index was similar between groups. Body mass index was significantly higher and percent excess weight loss was significantly lower in the WR group (P<.001). Average weight regain was 19.5±9.3 kg and-.8±8.5 in the WR and SWL groups, respectively (P<.001). Time elapsed since RYGB was significantly longer in the WR group (WR 6.0±2.4 years versus SWL 3.3±1.8 years; P<.001; range 2-12 yr). Patients in the WR group were significantly younger (WR 42.3±9.8 yr versus SWL 45.7±10.8 years; P<.001), had fewer co-morbidities, and were less likely to have type 2 diabetes with insulin dependence preoperatively. Univariate analysis found that older age, male gender, having hypertension, dyslipidemia, and insulin-treated type 2 diabetes were all factors associated with sustained weight loss. Moreover, a longer duration after RYGB was associated with weight regain. Multivariate analysis revealed that younger age was a significant predictor of weight regain even after adjusting for time since RYGB.
  
  
  CONCLUSIONS
  The present study confirmed that a longer interval after RYGB was associated with weight regain. Younger age was a significant predictor of weight regain even after adjusting for time since RYGB. The findings of this study underscore the complexity of the mechanisms underlying weight loss and regain after RYGB. Future prospective studies are needed to further explore the prevalence, predictors, and mechanisms of weight regain after RYGB.
authors.affiliation: Division of Nutrition and Biochemical Medicine, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; Center for Weight Loss and Bariatric Surgery, Department of General Surgery, Rush University Medical Center, Chicago, IL.
authors.forename: Prapimporn Chattranukulchai
authors.initials: PC
authors.lastname: Shantavasinkul
authors.affiliation: Metabolic and Weight Loss Surgery, Department of Surgery, Duke University Medical Center, Durham, NC.
authors.forename: Philip
authors.initials: P
authors.lastname: Omotosho
authors.affiliation: Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, NC.
authors.forename: Leonor
authors.initials: L
authors.lastname: Corsino
authors.affiliation: Center for Weight Loss and Bariatric Surgery, Department of General Surgery, Rush University Medical Center, Chicago, IL.
authors.forename: Dana
authors.initials: D
authors.lastname: Portenier
authors.affiliation: Metabolic and Weight Loss Surgery, Department of Surgery, Duke University Medical Center, Durham, NC. Electronic address: alfonso_torquati@rush.edu.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Torquati
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000601:surgery*; D011300:Preoperative Care; D012008:Recurrence; D012189:Retrospective Studies; D013997:Time Factors; D015430:Weight Gain / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology; D055815:Young Adult
keywords: Bariatric surgery; Diabetes remission; Gastric bypass; Roux-en-Y gastric bypass; Weight recidivism; Weight regain