Insulin resistance predicts response to peginterferon-alpha/ribavirin combination therapy in chronic hepatitis C patients.

BACKGROUND/AIMS: Insulin resistance (IR) might be associated with hepatitis C virus (HCV) infection. This study aimed to elucidate impact of IR and beta-cell function on the response to peginterferon-alpha (PEG-IFN)/ribavirin combination therapy in chronic hepatitis C (CHC) patients.

METHODS

Three hundred and thirty patients without overt diabetes were treated with combination therapy with (PEG-IFN)/ribavirin for 24 weeks. The IR and beta-cell function were evaluated by homeostasis model assessment of IR (HOMA-IR) and homeostasis model assessment of beta-cell function (HOMA-beta) before treatment.

RESULTS

HCV genotype, pretreatment HCV RNA level and pretreatment HOMA-IR, but not HOMA-beta, were independent factors associated with sustained virologic response (SVR). In 150 patients with genotype 1b infection, pretreatment HCV RNA level, HOMA-IR and age were independent predictors for SVR. The significantly lower SVR rate in high HOMA-IR patients was observed in 76 patients with high HCV RNA levels (>or=400,000IU/mL) who were defined as 'difficult-to-treat' patients. The mean HOMA-IR of 'difficult-to-treat' patients was significantly lower in 42 sustained responders than in 34 non-responders.

CONCLUSIONS

IR was associated with SVR to (PEG-IFN)/ribavirin therapy for CHC, especially among 'difficult-to-treat' patients. These findings suggested clinical application of pretreatment HOMA-IR could enable treatment outcome to be predicted and treatment regimens to be determined.