Prevalence of diabetes mellitus in Japanese patients infected chronically with hepatitis C virus

Background. To examine the relationship between hepatitis C virus (HCV) infection and diabetes mellitus (DM) in Japanese populations, a retrospective study was done in 866 patients with chronic viral disease. Methods. The present study included 707 HCV-infected and 159 hepatitis B virus (HBV)-infected patients. The prevalences of HBV- and HCV-related cirrhosis were 32% and 33%, respectively. A case-control study was also conducted to determine the seroprevalence of HCV infection in a cohort of 459 diabetics. Results. The prevalence of DM was higher in HCV-infected patients (20.9%; P < 0.02) than in HBV-infected subjects (11.9%). In the cirrhotic patients, DM was observed in 30.8% of the subjects with HCV compared with 11.8% of those with HBV (P < 0.01). Multivariate analysis revealed that the major independent variables associated with type II DM were male sex (odds ratio, 1.54; p = 0.020) and cirrhosis (odds ratio, 1.97; P = 0.0007). The relative odds of the development of DM were calculated to be 3.2 times higher in HCV-infected cirrhotic patients than in HBV-infected ones. In the case-control study of the diabetic cohort, 10.5% of patients were infected with HCV compared with 1.1% with HBV (P < 0.0001). The results indicate that HCV infection is closely associated with DM, compared with HBV infection. Cirrhosis was an independent risk factor for DM. Conclusions. Taken together, the findings indicate that cirrhosis appears to be a more important predictor of glucose intolerance than HCV infection, and the combination of both factors increases the risk of DM in our populations.