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Effects of bariatric surgery on nonalcoholic fatty liver disease: Preliminary findings after 2 years


Dr Claudia Pinto Marques Souza de Oliveira, Departamento de Gastroenterologia, Faculdade de Medicina da Universidade de São Paulo, Av. Dr Eneas de Carvalho Aguiar n° 255, ICHC 9° andar, sala 9159, 05403000 São Paulo, Brazil. Email:


Background and Aim:  Although nonalcoholic fatty liver disease (NAFLD) is very common among morbidly obese patients, the effect of weight loss after bariatric surgery on inflammation and fibrosis related to NAFLD is still a matter of debate. The aim of this study was to evaluate the impact of Roux-en-Y gastric bypass (RYGB) surgery on NAFLD with a follow up of 2 years.

Methods:  Eighteen consecutive NAFLD patients with body mass index >40 kg/m2 undergoing gastroplasty with RYGB were enrolled, and wedge liver biopsy was obtained at the operation. After 2 years, these patients underwent percutaneous liver biopsy.

Results:  At baseline, 67% of patients had nonalcoholic steatohepatitis (NASH) and 33% had steatosis, according to the NASH Clinical Research Network Scoring System (NAS) for biopsy. Cirrhosis was present in 5.5% of the patients with NASH. After a mean excess weight loss of 60%, steatosis disappeared in 84% and fibrosis disappeared in 75% of the patients. Hepatocellular ballooning disappeared in 50%. A slight lobular inflammatory infiltrate remained in 81%, apparently unrelated to fatty degeneration. As liver biochemical variables had been found within normal limits in 92.3% of patients at initial biopsy, no difference was found 2 years later. Lipid profile and blood sugar plasma concentration were closer to normal in all patients after 2 years (P < 0.05).

Conclusions:  Aspects of NAFLD including steatohepatitis improved significantly with massive weight loss at 2 years after RYGB surgery. No patient in this series had progression of hepatic fibrosis.