The Pathogenesis, Complications and Therapeutic Strategy for Hepatitis C Virus-associated Insulin Resistance in the Era of Anti-viral Treatment

Recent experimental and clinical studies have shown that chronic hepatitis C virus (HCV) infection causes insulin resistance. Since insulin resistance decreases response to antiviral treatments, promotes inflammatory and fibrogenic reactions and increases a risk of hepatocellular carcinoma (HCC), amelioration of insulin resistance may be a novel therapeutic target, which could improve the prognosis in patients with HCV-related chronic liver disease. Despite the increased awareness of health risk of insulin resistance, there is no common therapeutic strategy for HCV-associated insulin resistance. Indeed, treatments with exogenous insulin or sulfonylureas may be rather harmful because these treatments are associated with the development of HCC in patients with HCV infection. Meanwhile, we, along with others, have found distinctive treatments which improve HCV-associated insulin resistance. Administration of branched-chain amino acids (BCAA), especially as a late evening snack, improves glucose metabolism by improving insulin-signal cascades in insulin resistance patients with HCV infection. In this paper, we discuss the pathogenesis and complications for HCV-associated insulin resistance and further review a recent clinical therapeutic strategy using these agents for the treatment of this devastating disorder. We also discuss therapeutic potentialities of incretin-based therapies, new anti-diabetic agents for HCV-associated insulin resistance and the significance of insulin resistance in the era of new anti-viral treatments.