Background/Aims: Nonalcoholic fatty liver disease (NAFLD) is highly prevalent in type 2 diabetes mellitus (T2DM). However, data regarding the prevalence and correlates of its histopathological stages are scarce. The aim was to investigate the prevalence and correlates of the more severe histopathological features of NAFLD, nonalcoholic steatohepatitis (NASH) and advanced fibrosis, in T2DM. Methods: From 125 patients with ultrasonographic evidence of NAFLD, 98 patients underwent liver biopsies, which were examined by two independent pathologists regarding the presence of NASH and graded according to the NASH Clinical Research Network scoring system. Agreement between pathologists was assessed by weighted κ coefficients and independent correlates of NASH and advanced fibrosis (grade ≥2) by multivariate logistic regression. Results: Ninety-two (94%) patients presented histological NAFLD. Interobserver agreement was substantial to excellent for NASH diagnosis (κ=0.82) and steatosis grading (κ=0.76), and moderate for the NAFLD activity score (κ=0.58) and fibrosis grading (κ=0.52). The prevalence of NASH was 78%, and its independent correlates were hypertriglyceridaemia (P=0.034), high alanine aminotranferase level (P=0.044) and low serum high-density lipoprotein-cholesterol (P=0.079). The prevalence of advanced fibrosis ranged from 34% in the best scenario (lowest fibrosis score) to 60% in the worst scenario (highest score). Its independent correlates were a high serum γ-glutamyl transferase (P=0.002), older age (P=0.022) and male gender (P=0.064). No diabetes-related clinical characteristic was associated with NASH or advanced liver fibrosis. Conclusions: The prevalence of the severe features of NAFLD is high in T2DM patients. Liver biopsy shall be considered in all diabetic patients with ultrasonographic evidence of NAFLD.
