Nonalcoholic fatty liver disease in patients with different baseline glucose status undergoing bariatric surgery: analysis of intraoperative liver biopsies and literature review

Abstract

Background: Bariatric surgery has been investigated as a treatment option for obese patients with nonalcoholic fatty liver disease (NAFLD). Because patients with NAFLD and type 2 diabetes show accelerated progression from liver disease to cirrhosis, it has been suggested that surgery could be indicated for patients with lower degrees of obesity and type 2 diabetes.

Objective: To analyze the degree of tissue damage in liver biopsies obtained from patients undergoing bariatric surgery, correlating histopathologic findings with their baseline glucose status.

Setting: General hospital in the public health system.

Methods: Intraoperative liver biopsies were obtained from 521 obese patients undergoing bariatric surgery. Patients were divided into 3 study groups according to their preoperative glucose levels: 167 (32.05%) type 2 diabetic, 132 (25.33%) prediabetic, and 222 (42.61%) normoglycemic patients. Tissue samples were classified in accordance with Brunt and Clinical Research Network Nonalcoholic Steatohepatis criteria.

Results: Prevalence of NAFLD was 95%. Higher rates of hepatic fibrosis were observed in diabetic patients (56.4%) compared with prediabetic (29.2%), and normoglycemic patients (28.6%) (P<.001). Nonalcoholic steatohepatitis was diagnosed in 59.4% of the diabetics, in 49.2% of the prediabetics, and in 36% of the normoglycemic obese (P<.001). Only 1.5% of the diabetics had no histologic hepatic alterations.

Conclusion: NAFLD is markedly more severe in diabetic patients. Our data suggest that intraoperative liver biopsy should be considered for diabetic patients undergoing bariatric surgery. Early bariatric surgery should be investigated as a means to prevent progression of NAFLD.

Keywords: Bariatric surgery; NAFLD; Obesity; Type 2 diabetes.