title: Weight Loss and Heart Failure: A Nationwide Study of Gastric Bypass Surgery Versus Intensive Lifestyle Treatment.
abstract: BACKGROUND
  Associations of obesity with incidence of heart failure have been observed, but the causality is uncertain. We hypothesized that gastric bypass surgery leads to a lower incidence of heart failure compared with intensive lifestyle modification in obese people.
  
  
  METHODS
  We included obese people without previous heart failure from a Swedish nationwide registry of people treated with a structured intensive lifestyle program and the Scandinavian Obesity Surgery Registry. All analyses used inverse probability weights based on baseline body mass index and a propensity score estimated from baseline variables. Treatment groups were well balanced in terms of weight, body mass index, and most potential confounders. Associations of treatment with heart failure incidence, as defined in the National Patient Register, were analyzed with Cox regression.
  
  
  RESULTS
  The 25 804 gastric bypass surgery patients had on average lost 18.8 kg more weight after 1 year and 22.6 kg more after 2 years than the 13 701 lifestyle modification patients. During a median of 4.1 years, surgery patients had lower heart failure incidence than lifestyle modification patients (hazard ratio, 0.54; 95% confidence interval, 0.36-0.82). A 10-kg achieved weight loss after 1 year was related to a hazard ratio for heart failure of 0.77 (95% confidence interval, 0.60-0.97) in both treatment groups combined. Results were robust in sensitivity analyses.
  
  
  CONCLUSIONS
  Gastric bypass surgery was associated with approximately one half the incidence of heart failure compared with intensive lifestyle modification in this study of 2 large nationwide registries. We also observed a graded association between increasing weight loss and decreasing risk of heart failure.
authors.affiliation: From Department of Medical Sciences, Uppsala University, and Uppsala Clinical Research Center, Sweden (J.S.); Department of Medicine, Solna, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden (G.B., M.N.); Department of Surgery, Faculty of Medicine and Health, Örebro University, Sweden (J.O., I.N.); and Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden (C.M.). johan.sundstrom@medsci.uu.se.
authors.forename: Johan
authors.initials: J
authors.lastname: Sundström
authors.affiliation: From Department of Medical Sciences, Uppsala University, and Uppsala Clinical Research Center, Sweden (J.S.); Department of Medicine, Solna, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden (G.B., M.N.); Department of Surgery, Faculty of Medicine and Health, Örebro University, Sweden (J.O., I.N.); and Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden (C.M.).
authors.forename: Gustaf
authors.initials: G
authors.lastname: Bruze
authors.affiliation: From Department of Medical Sciences, Uppsala University, and Uppsala Clinical Research Center, Sweden (J.S.); Department of Medicine, Solna, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden (G.B., M.N.); Department of Surgery, Faculty of Medicine and Health, Örebro University, Sweden (J.O., I.N.); and Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden (C.M.).
authors.forename: Johan
authors.initials: J
authors.lastname: Ottosson
authors.affiliation: From Department of Medical Sciences, Uppsala University, and Uppsala Clinical Research Center, Sweden (J.S.); Department of Medicine, Solna, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden (G.B., M.N.); Department of Surgery, Faculty of Medicine and Health, Örebro University, Sweden (J.O., I.N.); and Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden (C.M.).
authors.forename: Claude
authors.initials: C
authors.lastname: Marcus
authors.affiliation: From Department of Medical Sciences, Uppsala University, and Uppsala Clinical Research Center, Sweden (J.S.); Department of Medicine, Solna, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden (G.B., M.N.); Department of Surgery, Faculty of Medicine and Health, Örebro University, Sweden (J.O., I.N.); and Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden (C.M.).
authors.forename: Ingmar
authors.initials: I
authors.lastname: Näslund
authors.affiliation: From Department of Medical Sciences, Uppsala University, and Uppsala Clinical Research Center, Sweden (J.S.); Department of Medicine, Solna, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden (G.B., M.N.); Department of Surgery, Faculty of Medicine and Health, Örebro University, Sweden (J.O., I.N.); and Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden (C.M.).
authors.forename: Martin
authors.initials: M
authors.lastname: Neovius
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects / Q000379:methods*; D006333:Heart Failure / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000517:prevention & control*; D006801:Humans; D015994:Incidence; D010535:Laparoscopy / Q000009:adverse effects; D008297:Male; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery*; D057216:Propensity Score; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D040242:Risk Reduction Behavior; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D016896:Treatment Outcome; D015431:Weight Loss
keywords: bariatric surgery; diet, reducing; gastric bypass; heart failure; weight loss