title: Long-term follow-up after bariatric surgery: a systematic review.
abstract: OBJECTIVE
  Bariatric surgery is an accepted treatment for obesity. Despite extensive literature, few studies report long-term follow-up in cohorts with adequate retention rates.
  
  
  OBJECTIVE
  To assess the quality of evidence and treatment effectiveness 2 years after bariatric procedures for weight loss, type 2 diabetes, hypertension, and hyperlipidemia in severely obese adults.
  
  
  METHODS
  MEDLINE and Cochrane databases were searched from 1946 through May 15, 2014. Search terms included bariatric surgery, individual bariatric procedures, and obesity. Studies were included if they described outcomes for gastric bypass, gastric band, or sleeve gastrectomy performed on patients with a body mass index of 35 or greater, had more than 2 years of outcome information, and had follow-up measures for at least 80% of the initial cohort. Two investigators reviewed each study and a third resolved study inclusion disagreements.
  
  
  RESULTS
  Of 7371 clinical studies reviewed, 29 studies (0.4%, 7971 patients) met inclusion criteria. All gastric bypass studies (6 prospective cohorts, 5 retrospective cohorts) and sleeve gastrectomy studies (2 retrospective cohorts) had 95% confidence intervals for the reported mean, median, or both exceeding 50% excess weight loss. This amount of excess weight loss occurred in 31% of gastric band studies (9 prospective cohorts, 5 retrospective cohorts). The mean sample-size-weighted percentage of excess weight loss for gastric bypass was 65.7% (n = 3544) vs 45.0% (n = 4109) for gastric band. Nine studies measured comorbidity improvement. For type 2 diabetes (glycated hemoglobin <6.5% without medication), sample-size-weighted remission rates were 66.7% for gastric bypass (n = 428) and 28.6% for gastric band (n = 96). For hypertension (blood pressure <140/90 mm Hg without medication), remission rates were 38.2% for gastric bypass ( n = 808) and 17.4% for gastric band (n = 247). For hyperlipidemia (cholesterol <200 mg/dL, high-density lipoprotein >40 mg/dL, low-density lipoprotein <160 mg/dL, and triglycerides <200 mg/dL), remission rates were 60.4% for gastric bypass (n = 477) and 22.7% for gastric band (n = 97).
  
  
  CONCLUSIONS
  Very few bariatric surgery studies report long-term results with sufficient patient follow-up to minimize biased results. Gastric bypass has better outcomes than gastric band procedures for long-term weight loss, type 2 diabetes control and remission, hypertension, and hyperlipidemia. Insufficient evidence exists regarding long-term outcomes for gastric sleeve resections.
authors.affiliation: Department of Surgery, University of Texas Southwestern Medical Center, Dallas2Department of Surgery, North Texas Veterans Administration Healthcare System, Dallas.
authors.forename: Nancy
authors.initials: N
authors.lastname: Puzziferri
authors.affiliation: Department of Surgery, University of Texas Southwestern Medical Center, Dallas.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Roshek
authors.affiliation: University of Texas Southwestern Medical Center Library, Dallas.
authors.forename: Helen G
authors.initials: HG
authors.lastname: Mayo
authors.affiliation: Department of Surgery, University of Texas Southwestern Medical Center, Dallas.
authors.forename: Ryan
authors.initials: R
authors.lastname: Gallagher
authors.affiliation: Departments of Epidemiology and Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Belle
authors.affiliation: Department of Surgery, University of Texas Southwestern Medical Center, Dallas2Department of Surgery, North Texas Veterans Administration Healthcare System, Dallas5Department of Biomedical Engineering, University of Texas-Arlington, Arlington6Deputy Edito.
authors.forename: Edward H
authors.initials: EH
authors.lastname: Livingston
mesh_terms: D050110:Bariatric Surgery; D003920:Diabetes Mellitus; D023381:Endpoint Determination; D005500:Follow-Up Studies; D006801:Humans; D006949:Hyperlipidemias / Q000150:complications; D006973:Hypertension / Q000150:complications; D009765:Obesity / Q000150:complications / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D015431:Weight Loss