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

Abstract

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.

Keywords: Bariatric surgery; NAFLD; Obesity.