High incidence of type 1 diabetes mellitus during or shortly after treatment with pegylated interferon alpha for chronic hepatitis C virus infection

Background: Development of diabetes mellitus (DM) during or shortly after treatment with interferon a (IFN-a) in patients with chronic hepatitis C virus (HCV) infection has been reported sporadically. We prospectively screened for DM during and after IFN-a therapy for chronic HCV infection. Methods: Blood glucose levels of patients with chronic HCV infection were routinely assessed at all outpatient visits during and after treatment with pegylated-IFN-a (Peg-IFN-a) and ribavirin (Riba). Results: Between December 2002 and October 2005, 189 non-diabetic patients were treated with Peg-IFN-a/Riba, of whom five developed type 1 DM (2.6%), three type 2 DM (1.6%) and one an indeterminate type of DM. Classical symptoms of DM were present in three patients who developed DM shortly after cessation of Peg-IFN-a/Riba. In the other patients, symptoms of DM were either indistinguishable from side effects caused by Peg-IFN-a/Riba or absent. Conclusion: Our study showed a high incidence of type 1 DM during PegIFN-a/Riba therapy for chronic HCV infection. Symptoms of DM may be absent or mistaken for Peg-IFN-a/Riba-associated side effects. To diagnose DM without delay, we propose routine assessment of blood glucose at all outpatient visits during and after Peg-IFN-a/Riba treatment in chronic HCV patients.