Type 2 diabetes mellitus and chronic hepatitis C: Which is worse? Results of a long-term retrospective cohort study

Background: The long-term outcome in patients with chronic hepatitis C and type 2 diabetes mellitus treated with interferon and ribavirin is unclear. We compared incidence of liver-related events and mortality rates between hepatitis C virus-positive patients with or without diabetes mellitus, and the incidence of diabetes-related events between diabetic patients with and without hepatitis C. Methods: Retrospective study of 309 patients with chronic hepatitis C. Incidence of liver-related events, diabetes-related events and mortality rates were assessed over a mean follow-up of 11.02±4.9 years. Results: 50 (16%) chronic hepatitis C patients had diabetes mellitus. Diabetics showed a higher number of diabetes- and liver-related events than non-diabetics (10% vs 1.5%, p=0.006; 18% vs 5.7%, p=0.007, respectively) with a mortality of 14% vs 1.5% (p=0.0003). Baseline cirrhosis (p=0.002) and non-sustained virological response (p=0.01) were independent risk factors for liver events; diabetes mellitus (p=0.01) and hypertension (p=0.0017) were independent factors for diabetes-related events. Conclusions: In patients with chronic hepatitis C, comorbidity with diabetes mellitus was associated with a higher mortality rate and incidence of liver/diabetes-related events. Independent risk factors for liver-related events were the non-response to antiviral therapy and cirrhosis at baseline.