Insulin resistance and metabolic syndrome are related to non-alcoholic fatty liver disease, but not visceral adiposity index, in severely obese patients

The visceral adiposity index (VAI) is a marker of visceral fat distribution and dysfunction. Visceral adiposity is related to non-alcoholic fatty liver disease (NAFLD); however, there is some controversy regarding the association between VAI and NAFLD. The aim of this study was to analyse the relationship between VAI and NAFLD and to describe the related factors in severely obese patients. A total of 139 patients who underwent bariatric surgery were included in this cross-sectional study. Liver biopsy was performed during surgery. Univariate and multivariate analysis were conducted to study the features related to VAI. A univariate analysis was conducted to identify which factors were associated with liver histology. In the univariate analysis, steatosis, liver inflammation, non-alcoholic steatohepatitis (NASH) and fibrosis were associated with VAI. In the multivariate analysis, only HOMA (Beta: 0.06; p < 0.01) and metabolic syndrome (Beta: 1.23; p < 0.01) were related to VAI. HOMA, the presence of metabolic syndrome, and waist circumference (WC) were statistically related to the NAFLD activity score (NAS score): HOMA: 0-2: 5.04; 3-4: 7.83; ≥ 5: 11,32; p < 0.01; MS: 0-2: 37 %; 3-4: 33.3 %; ≥ 5: 76%; p < 0.01; WC: 0-2: 128.7 cm; 3-4: 130.7; ≥ 5: 140.6; p < 0.01). For the prediction of NASH (NAS score ≥ 5), the AUROC curve were 0.71 (CI 95 %: 0.63-0.79) for VAI and 0.7 (CI 95 %: 0.62-0.78) for WC. In conclusion, HOMA, WC and metabolic syndrome are related to liver histology in patients with severe obesity. In the multivariate analysis, VAI was associated with HOMA and metabolic syndrome, but not with liver histology