People who have been infected with herpes simplex virus type 1 (HSV-1) - the variety that usually causes ‘cold sores’ rather than genital infections - appear to have an increased risk of developing type 2 diabetes, according to a report from China.

Previous studies have implicated hepatitis C virus infection as a risk factor for type 2 diabetes. However, it is a possible that infection with other viruses, such as HSV-1, may make people more prone to develop the disease as well.

To investigate, Dr. Yuejin Yang and colleagues, from the Peking Union Medical College in Beijing, tested 206 subjects with type 2 diabetes for HSV-1 infection, along with a control group of 1360 without diabetes.

To avoid possible confusion, all of the subjects were negative for hepatitis C virus antibodies, the investigators state in the medical journal Diabetes Care.

Forty-six percent of diabetic subjects were infected with HSV-1 compared with 36 percent of controls. Moreover, individuals with diabetes made up for 16 percent of the group with HSV-1 but only 11 percent of those free of the virus.

When they analyzed the data, the investigators concluded that the presence of HSV-1 infection raised the risk of type 2 diabetes by 50 percent.

This association between HSV-1 infection and type 2 diabetes further supports the idea that inflammation and virus infection increase the risk of type 2 diabetes, the team points out.

SOURCE: Diabetes Care, February 2005.