Roux-en-Y Gastric Bypass Vs. Adjustable Gastric Banding
Roux-en-Y Gastric Bypass Vs. Adjustable Gastric Banding
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), 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, 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.
Nonalcoholic fatty liver disease (NAFLD) is becoming a common chronic liver disease in Western countries. It is defined by the presence of hepatic steatosis, based on histology or imaging, after excluding all causes of secondary hepatic fat accumulation such as alcohol consumption, steatogenic medication, or hereditary disorders. In patients with NAFLD, histological features can progress from simple steatosis to steatohepatitis [nonalcoholic steatohepatitis (NASH)], advanced fibrosis, cirrhosis, and hepatocarcinoma. In most cases, NAFLD is associated with metabolic comorbidities such as obesity, dyslipidemia, insulin resistance, and type 2 diabetes mellitus (T2DM). Thus, substantial weight loss leads to an attenuation of insulin resistance and related metabolic syndrome and, concomitantly, a regression of liver steatosis.
Bariatric surgery is the most effective treatment option for severe obesity and associated metabolic comorbidities. Several longitudinal studies, including 2 reports from our center, have documented the marked benefit of bariatric surgery on NAFLD in close relation to the reversal of insulin resistance. No study has, however, compared the effect of the various types of bariatric procedures on liver disease. In the present study, we compared the effect of adjustable gastric banding (AGB), a strictly restrictive procedure, and Roux-en-Y gastric bypass (RYGB), a more complex operation that is associated with restriction, malabsorption, and gut hormones modulation, on NAFLD.
Abstract and Introduction
Abstract
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), 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, 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.
Introduction
Nonalcoholic fatty liver disease (NAFLD) is becoming a common chronic liver disease in Western countries. It is defined by the presence of hepatic steatosis, based on histology or imaging, after excluding all causes of secondary hepatic fat accumulation such as alcohol consumption, steatogenic medication, or hereditary disorders. In patients with NAFLD, histological features can progress from simple steatosis to steatohepatitis [nonalcoholic steatohepatitis (NASH)], advanced fibrosis, cirrhosis, and hepatocarcinoma. In most cases, NAFLD is associated with metabolic comorbidities such as obesity, dyslipidemia, insulin resistance, and type 2 diabetes mellitus (T2DM). Thus, substantial weight loss leads to an attenuation of insulin resistance and related metabolic syndrome and, concomitantly, a regression of liver steatosis.
Bariatric surgery is the most effective treatment option for severe obesity and associated metabolic comorbidities. Several longitudinal studies, including 2 reports from our center, have documented the marked benefit of bariatric surgery on NAFLD in close relation to the reversal of insulin resistance. No study has, however, compared the effect of the various types of bariatric procedures on liver disease. In the present study, we compared the effect of adjustable gastric banding (AGB), a strictly restrictive procedure, and Roux-en-Y gastric bypass (RYGB), a more complex operation that is associated with restriction, malabsorption, and gut hormones modulation, on NAFLD.
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