Human immunodeficiency virus is the major determinant of steatosis and hepatitis C virus of insulin resistance in virus-associated fatty liver disease.

Background And Aims: To promote our understanding of the relative contribution of metabolic and viral factors, the independent predictors of fatty liver and insulin resistance (IR) were assessed by comparing patients with nonalcoholic fatty liver disease (NAFLD) to individuals with virus-associated fatty liver disease (VAFLD): human immunodeficiency virus (HIV)-VAFLD, hepatitis C virus (HCV)-VAFLD and HIV-HCV-VAFLD.

Methods: One hundred eighty eight consecutive patients with viral infections (103 HIV, 85 patients with HCV genotype 1 infection: 45 mono-infected and 40 HIV/HCV co-infected) with or without steatosis and 126 NAFLD patients were analyzed. Steatosis was diagnosed by ultrasonography. To assess the odds ratio (OR) of steatosis and IR, HCV and NAFLD, respectively, were used as the reference values. IR was evaluated through homeostasis model (HOMA) and the metabolic syndrome (MetS) using standard criteria.

Results: The prevalence of VAFLD was 47%. Multivariate logistic regression analysis was carried out using HCV as the reference. VAFLD was predicted by HIV, HIV/HCV, female gender, waist circumference (WC) and HOMA (OR = 3.99, 3.76, 2.80, 1.08 and 1.18). According to multiple linear regression using NAFLD as the reference, IR was predicted by HCV, HIV and HIV/HCV, WC, triglycerides (coefficient beta = 2.25, 0.99, 1.86, 0.08, 0.05, respectively). In linear models, for any given number of components of MetS, HCV and HCV/HIV-associated fatty liver disease had greater HOMA compared to NAFLD (p <0.001).

Conclusions: Whereas HIV confers a higher risk of steatosis, VAFLD is associated with higher IR than NAFLD and such an effect is specifically linked to HCV rather than to HIV infection.