Risk of non alcoholic steatohepatitis and fibrosis in patients with non alcoholic fatty liver disease and low visceral adiposity

BACKGROUND AND AIMS: Increased visceral adiposity is considered the hallmark of the metabolic syndrome, whose hepatic manifestation is nonalcoholic fatty liver disease (NAFLD), although a subset of patients does not have visceral obesity. Aim: To compare metabolic alterations and liver damage in patients with NAFLD with and without visceral obesity. METHODS: 431 consecutive patients with liver biopsy-confirmed NAFLD were divided in three groups according to waist circumference, the simplest surrogate marker of visceral obesity. One hundred and thirty three (31%) had waist circumference ⩽ 94 (males) and ⩽ 80 cm (females) (group A), 157 (36%) between 94 and 102 and 80 and 88 (B), and the remaining 141 (33%) values higher than 102 and 88 cm (C). RESULTS: Significant trends for older age, higher prevalence of female sex , lower HDL, higher triglycerides, altered glucose metabolism, hypertension and metabolic syndrome were observed with increasing visceral adiposity. In contrast, non-alcoholic steatohepatitis (NASH) detected in 55% and 72% of patients with normal and increased waist circumference and the presence of fibrosis >2 were not associated with visceral adiposity. Alanine aminotransferase (ALT), ferritin, HOMA-IR > 4, and severe steatosis were independently associated with NASH, whereas ferritin and impaired glucose tolerance were associated with fibrosis >2. CONCLUSION: Patients with normal waist circumference, despite milder metabolic alterations, may have NASH and are at risk of developing fibrosis, suggesting that once NAFLD is present, visceral obesity is not a major determinant of liver damage severity.