An Association between Hepatitis C Virus Infection and Type 2 Diabetes Mellitus: What Is the Connection?

• Hepatitis C
• Diabetes mellitus, non-insulin-dependent
• Liver cirrhosis
• Insulin resistance
• Hepatitis C-like viruses

Chronic hepatitis C virus infection (HCV) and type 2 diabetes mellitus cause devastating long-term complications in a significant minority of affected patients. A link between the two disorders would not be surprising: Chronic HCV infection may cause cirrhosis, which, through insulin resistance, predisposes patients to diabetes mellitus. Moreover, both disorders are common. Recent cross-sectional studies performed worldwide suggest that they are indeed closely linked.

What is the evidence? From the hepatologist's viewpoint, type 2 diabetes mellitus seems to be more common in HCV-infected persons. Allison and coworkers (1) found that among patients with cirrhosis awaiting transplantation, those who were infected with HCV were five times more likely to have type 2 diabetes mellitus than those who were not, regardless of sex, body mass index, or severity of liver disease. These findings were replicated in patients with less severe liver disease: Those with HCV infection were almost three times more likely to have type 2 diabetes mellitus than those with hepatitis B virus (HBV) infection or alcohol-related liver disease (2). An Egyptian study showed that incidence of type 2 diabetes mellitus increased twofold in patients who had HCV infection compared with those who did not and reported that HCV-infected persons with type 2 diabetes mellitus were more likely to need insulin (3).

A large retrospective survey of 1332 Italian patients with cirrhosis found that type 2 diabetes mellitus was present in 23.6% of those with HCV infection and in 9.4% of those with HBV …