Epidemiology

Hepatitis C highly associated with diabetes, study confirms

Last Updated: 2007-07-20 17:21:24 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Hepatitis C virus (HCV) infection independently raises the risk of type 2 diabetes, a population-based study confirms. The risk is particularly high in younger, anti-HCV+ people who are overweight, researchers from Taiwan have found.

Therefore, screening for and prevention of diabetes in persons with HCV infection could be started earlier than the suggested age of 45 or older for the general population, "especially for those with higher body mass index levels or with other risk factors for diabetes," Dr. Chong-Shan Wang from National Yang-Ming University, Taipei, and colleagues write in the July 15 American Journal of Epidemiology.

Among 4,958 people aged 40 or older without diabetes, 3,486 were seronegative, 812 were anti-HCV+, 116 had HBV/HCV coinfection, and 544 were positive for hepatitis B surface antigen (HBsAg+).

A total of 474 people developed diabetes during the 7 years that they were followed. After adjusting for established risk factors for diabetes, the incidence of diabetes was 70% higher in persons with HCV infection relative to persons without HCV infection, Dr. Wang and colleagues report.

"HBV plus HCV-coinfected and anti-HCV+ alone persons had nearly the same risk, which indicates that HCV infection increases the risk of diabetes but HBV infection does not," the authors note. "This finding is consistent with past studies showing that HCV infection is highly associated with diabetes."

In stratified age groups, the risk ratio ranged from 2.2 in 40- to 49-year-olds to 1.7 in 50- to 64-year-olds. This implies that "the younger the persons with HCV infection, the greater the risk that they will develop diabetes than their age-group counterparts without HCV infection," the Taiwan team notes.

The coexistence of HCV infection and overweight or obesity showed a synergistic effect on the occurrence of diabetes. "The risk of diabetes for anti-HCV+ persons who are either overweight or obese is about three times that for anti-HCV+ persons of normal weight," Dr. Wang and colleagues report.

They conclude that regular diabetes screening for anti-HCV+ persons "is indicated and can be started at a younger age, especially for those at high risk."

Am J Epidemiol 2007;166:196-203.