Impact of Bariatric Surgery on Nonalcoholic Fatty Liver Disease Assessed through Validated Fibrosis Scores

Abstract

Introduction Nonalcoholic fatty liver disease (NAFLD) is common among morbid obese (MO) with estimated prevalence of 90%. Weight loss (WL) play a main role in its control. Objective To determine the evolution of NAFLD by means of validated fibrosis scores 12 months after bariatric surgery (BS) and measure its impact. Methods Retrospective observational study which enrolled MO who underwent BS at a University Hospital in Madrid, Spain during 2014 and 2015. Patients features were collected at baseline and compared at 12 months after BS. NAFLD fibrosis and FIB-4 scores were calculated. Results 50 patients (37 women, 74%), mean age 44 ± 12 years. At baseline, mean weight was 124.98 ± 19.88 kg, Body Mass Index (BMI) 45.74 ± 5.93 kg/m2, Basal Glycaemia (BG) 104 ± 25 mg/dL, glycated hemoglobin (HbA1c) 5.9 ± 0.8%, alanine aminotransferase (ALT) 27 (12-125) IU, aspartate aminotransferase (AST) 22 (11-126) IU, gamma glutamyl transpeptidase (GGT) 35 (7-216) IU, alkaline phosphatase (AP) 72 (17-159) IU. NAFLD fibrosis and FIB-4 scores were 1.859 (-1.755-4.631) and 0.72 (0.22-3.05), respectively. In the postoperative period, mean weight was 84.17 ± 15.93 kg, BMI 30.76 ± 4.52 kg/m2, BG 85 ± 12 mg/dL, HbA1c 5.3 ± 0.31%, ALT 20 (9-133) IU, AST 20 (11-80) IU, GGT 18 (6-237) IU, AP 75 (8-183) IU. NAFLD fibrosis and FIB-4 scores were 0.412 (-2.643- 4.661) and 0.78 (0.38-1.79), respectively. Mean WL was 40.75 ± 14.59 kg, mean percentage of excess WL after BS was 73.23 ± 20.79%, and mean percentage of excess BMI loss was 72.92 ± 19.36%. Weight, BMI, BG, HbA1c, ALT, GGT, total cholesterol and triglycerides significantly improved after BS, as well as type 2 diabetes, hypertension and dyslipidemia whose prevalence declined. NAFLD fibrosis score significantly decrease after BS, but FIB-4 did not. These two scores were strongly correlated between them. Conclusions BS is an effective intervention to control the progression of NAFLD evaluated through clinical parameters, analytical values and fibrosis scores, of which NAFLD score is better than FIB-4 index.