| Background. Nearly 25 studies have suggested a link between hepatitis C virus (HCV) infection and diabetes mellitus; however, several important questions remain. The objective of this study was to investigate the relationship between HCV infection and type 2 diabetes in two community based-settings, where potential confounding variables were assessed and a temporal relationship could be established.; Methods. We first performed a cross-sectional analysis among 9841 persons in the third National Health and Nutrition Examination Survey (NHANES III). The prevalence of type 1 and type 2 diabetes was determined among persons with and without HCV infection. We then examined the relationship between HCV infection and incident type 2 diabetes in a case-cohort analysis among 1093 persons from the Atherosclerosis Risk in Communities Study (ARIC). Random samples stratified by race were selected of both incident cases of type 2 diabetes (n = 535) and members of the cohort at baseline (n = 615). HCV infection was assessed by testing for HCV-specific antibodies (anti-HCV) on stored visit 1 plasma samples.; Results. In the NHANES III analysis, among persons 40 years of age or older, individuals with HCV infection were greater than three times as likely than those without HCV infection to have type 2 diabetes (adjusted odds ratio, 3.77; 95% confidence interval [CI], 1.80–7.87) after adjusting for age, gender, ethnicity, body mass index, poverty index, family history of diabetes, illicit drug and alcohol use. None of the 230 individuals with HCV infection had type 1 diabetes. In the ARIC analysis, among persons at high risk of diabetes, the incidence of type 2 diabetes was higher among those with HCV infection compared to those without HCV infection (relative hazard [RH], 13.91; 95% confidence interval [CI], 1.67–115.71). An increased incidence of type 2 diabetes was not detected among HCV-infected persons at low risk of diabetes (RH, 0.53; 95% CI, 0.06–4.85).; Conclusion. HCV infection is independently associated with type 2 diabetes among persons in the general United States population and HCV infection antedates type 2 diabetes in individuals with both conditions. The greatest risk may be among those with HCV infection and additional risk factors for diabetes (e.g. older age and obesity). |
