Improvement of Nonalcoholic Fatty Liver Disease After Bariatric Surgery in Morbidly Obese Chinese Patients

Obesity is a risk factor for nonalcoholic fatty liver disease (NAFLD), which appears to improve after weight loss induced by bariatric surgery in Western countries. The present study aims to determine the alterations of clinical measurements and liver histology of NAFLD after bariatric surgery in morbidly obese Chinese patients. Between November 2006 and December 2007, 21 morbidly obese patients receiving intra-operative liver biopsy and follow-up liver biopsy 1 year after laparoscopic Roux-en-Y gastric bypass were enrolled. NAFLD activity score (NAS) and fibrosis stage were histologically evaluated. The mean body mass index fell from 43.8 +/- 7.5 to 28.3 +/- 4.6 kg/m(2) (P < 0.01). Biochemical improvement was found in serum levels of alanine aminotransferase (P < 0.01) and gamma-glutamyltransferase (P < 0.01), but not aspartate aminotransferase (P = 0.66). Histological improvement was noted in NAS (P < 0.01) and individual components, including steatosis (P < 0.01), ballooning degeneration (P < 0.01), and lobular inflammation (P = 0.02). Pre-operatively, 4 (19.0%), 11 (52.4%), and 6 (28.6%) patients were found to have NAS a parts per thousand 5, 3 or 4, and a parts per thousand broken vertical bar 2, respectively. All patients had NAS a parts per thousand broken vertical bar 2 after surgery. Fibrosis stage also showed significant improvement (P < 0.01). Bariatric surgery can achieve a dramatic improvement of NAFLD both biochemically and histologically in morbidly obese Chinese patients.