Whole-body insulin sensitivity index is a highly specific predictive marker for virological response to peginterferon plus ribavirin therapy in chronic hepatitis C patients with genotype 1b and high viral load.

Insulin resistance is a candidate predictive factor for virological response to peginterferon plus ribavirin (PEG/RBV) therapy in chronic hepatitis C patients. We examined whether indices of insulin resistance could serve as a predictor of sustained virological response (SVR). Fifty-one patients with genotype 1b and high viral load who received PEG/RBV therapy for 48 weeks were included. Homeostasis model assessment of insulin resistance (HOMA-IR) and whole-body insulin sensitivity index (WBISI) calculated from the 75-g oral glucose tolerance test and serum levels of soluble tumor necrosis factor receptor 2 (sTFNR2) were evaluated before therapy. Patients who achieved SVR had significantly lower HOMA-IR and sTNFR2 levels and a higher WBISI compared with non-SVR patients. The positive predictive value for SVR was 0.653 for a HOMA-IR of <2 and 0.846 for a WBISI of 6 or higher. WBISI may serve as a highly specific predictor for SVR in PEG/RBV therapy.