Sustained virological response to hepatitis C treatment decreases the incidence of complications associated with type 2 diabetes.

Background The role of hepatitis C (HCV) eradication on the long-term complications of type 2 diabetes mellitus remains incompletely studied. Aim To investigate whether antiviral treatment impacted risk of acute coronary syndrome, end-stage renal disease, ischaemic stroke, and retinopathy among diabetic patients from the four US health systems comprising the Chronic Hepatitis Cohort Study (CHeCS). Methods We included CHeCS HCV patients with diagnosis codes for type 2 diabetes who were on antidiabetic medications. Patients were followed until an outcome of interest, death, or last health system encounter. The effect of treatment on outcomes was estimated using the competing risk analysis (Fine-Gray subdistribution hazard ratio [sHR]), with death as a competing event. Results Among 1395 HCV-infected patients with type 2 diabetes, 723 (52%) were treated with either interferon-based or direct-acting antivirals (DAAs); 539 (75% of treated) achieved sustained virological response (SVR). After propensity score adjustment to address treatment selection bias, patients with SVR demonstrated significantly decreased risk of acute coronary syndrome (sHR = 0.36; P < 0.001), end-stage renal disease (sHR = 0.46; P < 0.001), stroke (sHR = 0.34; P < 0.001), and retinopathy (sHR = 0.24; P < 0.001) compared to untreated patients. Results were consistent in subgroup analyses of DAA-treated patients and interferon-treated patients, an analysis of cirrhotic patients, as well as in sensitivity analyses considering cause-specific hazards, exclusion of patients with on-treatment retinopathy, and treatment status as a time-varying covariate. Conclusion Successful HCV treatment among patients with type 2 diabetes significantly reduces incidence of acute coronary syndrome, end-stage renal disease, ischaemic stroke, and retinopathy, regardless of cirrhosis. Our findings support the importance of HCV antiviral therapy among patients with type 2 diabetes to reduce the risk of these extrahepatic outcomes.