Roux-en-Y Gastric Bypass Versus Adjustable Gastric Banding to Reduce Nonalcoholic Fatty Liver Disease A 5-Year Controlled Longitudinal Study

Objectives: To compare the long-term benefit of gastric bypass [Roux-en-Y gastric bypass (RYGB)] versus adjustable gastric banding (AGB) on nonalcoholic fatty liver disease (NAFLD) in severely obese patients. Background: NAFLD improves after weight loss surgery, but no histological study has compared the effects of the various bariatric interventions. Methods: Participants consisted of 1236 obese patients (body mass index = 48.4 +/- 7.6 kg/m(2)), enrolled in a prospective longitudinal study for up to 5 years after RYGB (n = 681) or AGB (n = 555). Liver biopsy samples were available for 1201 patients (97.2% of those at risk) at baseline, 578 patients (47.2%) at 1 year, and 413 patients (68.9%) at 5 years. Results: At baseline, NAFLD was present in 86% patients and categorized as severe [NAFLD activity score (NAS) >= 3] in 22% patients. RYGB patients had a higher body mass index (49.8 +/- 8.2 vs 46.8 +/- 6.5 kg/m(2), P < 0.001) and more severe NAFLD (NAS: 2.0 +/- 1.5 vs 1.7 +/- 1.4, P = 0.004) than AGB patients. Weight loss at 5 years was 25.5% +/- 11.8% after RYGB versus 21.4% +/- 12.7% after AGB (P < 0.001). When analyzed with a mixed model, all NAFLD parameters improved after surgery (P < 0.001) and improved significantly more after RYGB than after AGB [steatosis (%): 1 year, 7.9 +/- 13.7 vs 17.9 +/- 21.5, P < 0.001/5 years, 8.7 +/- 7.1 vs 14.5 +/- 20.8, P < 0.05; NAS: 1 year, 0.7 +/- 1.0 vs 1.1 +/- 1.2, P < 0.001/5 years, 0.7 +/- 1.2 vs 1.0 +/- 1.3, P < 0.05]. In multivariate analysis, the superiority of RYGB was primarily but not entirely explained by weight loss. Conclusions: The improvement of NAFLD was superior after RYGB than after AGB.