The Impact of Bariatric Surgery on Hepatic Function and Predictors of Liver Steatosis and Fibrosis

Purpose To evaluate the variation in parameters of hepatic function and in the scores Fatty Liver Index (FLI; predictor of hepatic steatosis) and BARD (BMI, AST/ALT ratio and DM, predictor of hepatic fibrosis), 1 year after bariatric surgery. Material and Methods This is a observational retrospective cohort study in patients with morbid obesity that underwent bariatric surgery in our centre. We used two linear regression models: (1) unadjusted and (2) adjusted for surgery type, sex, age, body mass index, diabetes, and dyslipidaemia. Results The included population (n = 1955) had an average age of 43.1 +/- 10 years and 85.8% were female. Diabetes was present in 32.4% of the patients, 45.1% had dyslipidaemia, and 62.2% had hypertension. Twelve percent were submitted to gastric band, 29.6% to sleeve gastrectomy, and 58.4% to gastric bypass. We observed a relevant decrease in transaminases and gamma-glutamyltransferase, and an increase in alkaline phosphatase and total bilirubin. Both FLI and BARD markedly decrease 1 year after surgery (p < 0.01). Comparing the surgical procedures, sleeve gastrectomy was associated with a greater reduction of hepatic enzymes and of both FLI and BARD compared with gastric band. Comparing with gastric bypass, sleeve was associated with a greater reduction of transaminases and alkaline phosphatase, but a smaller reduction of FLI and BARD. Conclusion Bariatric surgery is associated with a reduction of the hepatic enzymes and an improvement of FLI and BARD. It may represent an effective therapeutic approach for NAFLD.