Background/aims: Recent studies using transgenic mouse models have demonstrated that the presence of hepatitis C virus (HCV) singularly induces insulin resistance (IR). When evaluated in humans, the exclusion of other factors influencing IR, such as obesity, alcohol intake, hepatic inflammation and steatosis is needed, but only few studies have been performed to these ends. Therefore, we aimed at exploring the singular effects of HCV on glucose metabolism through analysis of HCV carriers with persistently normal serum aminotransferase.
Methods: Non-obese, non-diabetic and non-alcoholic HCV carriers (n=30) were enrolled with 30 hepatitis B virus carriers matched by age, gender, body mass index and waist-to-hip ratio. All patients maintained normal serum aminotransferase (<30 U/L), hyaluronic acid (<50 ng/ml) and platelet count (>150 x 10(3)/microl) for more than 5 years without additional treatments, and had no signs of steatosis. We then compared fasting plasma glucose, serum insulin and adiponectin, and homoeostasis model assessment of IR (HOMA-IR) and HOMA-beta indices between the groups.
Results: There were no significant differences in IR/secretion-associated markers or serum adiponectin. Multivariate analysis demonstrated that the presence of HCV was not an independent predictor of IR. HOMA-IR was strongly correlated with waist circumferences and serum gamma-glutamyltransferase in HCV carriers, but not with serum aminotransferase, high-sensitivity C-reactive protein, hyaluronic acid or HCV core antigen.
Conclusions: These results suggest that the presence of HCV alone does not affect IR. Coexistence of hepatitis, steatosis and/or fibrosis may be important to the pathogenesis of IR induced by chronic HCV infection.