Visceral adiposity index is associated with significant fibrosis in patients with non-alcoholic fatty liver disease

Background Metabolic factors have been associated with liver damage in patients with non-alcoholic fatty liver disease (NAFLD). Aims To test a new marker of adipose dysfunction, the visceral adiposity index (VAI), in NAFLD patients to assess whether or not it is associated with host factors, and to investigate a potential correlation with histological findings. Methods One hundred and forty-two consecutive NAFLD patients were evaluated by liver biopsy, and clinical and metabolic measurements, including insulin resistance with the homeostasis model assessment (HOMA), and VAI by using waist circumference, body mass index, triglycerides and HDL. Serum levels of TNFa, IL-6, adiponectin and leptin were also assessed. All biopsies were scored for NAFLD activity score (NAS) and its components, and for staging (Kleiner). Results By multiple linear regression analysis, VAI was independently associated with higher HOMA (P = 0.04), and fibrosis (P = 0.04). In addition, an independent association was found between higher VAI and lower adiponectin levels (P = 0.002). Higher HOMA (OR 1.149, 95% CI 1.0031.316, P = 0.04), higher VAI (OR 1.446, 95% CI 1.0232.043, P = 0.03), lobular inflammation (OR 3.777, 95% CI 1.7718.051, P = 0.001), and ballooning (OR 2.884, 95% CI 1.2316.757, P = 0.01) were correlated with significant fibrosis (F2F4) on multiple logistic regression analysis. In particular, the prevalence of significant fibrosis progressively increased from patients with a VAI = 2.1 and HOMA = 3.4 (26%) to those with a VAI > 2.1 and HOMA > 3.4 (83%). Conclusions In NAFLD patients, visceral adiposity index is an expression of both qualitative and quantitative adipose tissue dysfunction and, together with insulin resistance, is independently correlated with significant fibrosis.