false low hba1c levels under treatment with ribavirin

Background: With increasing numbers of patients treated for hepatitis C, it will become more common that patients with diabetes will undergo those treatments as well. Up to now, only few data analysing HbA1c levels in diabetic patients under treatment for hepatitis C exists. Therefore, we compared changes of HbA1c levels during hepatitis C treatment in regimes with or without ribavirin Methods: 14 patients in a ribavirin containing and 20 in a non-ribavirin containing regimen were followed for their glycemic control before, during and after treatment. HbA1c and fructosamine were measured at week 0, 4, 8, and 12 while under therapy, and 4 and 12 weeks after end of treatment. Results: A significant decrease in HbA1c was shown in ribavirin treated patients, while no differences were found in the non-ribavirin containing group (ΔHbA1c week 0 to 12: ribavirin: -2.1±1.26 % / non-ribavirin: -0.25±0.1%; p <0.001). After treat -ment, HbA1c values returned to baseline levels. Fructosamine levels remained stable in both treatment groups. Conclusion: Ribavirin leads to inadequately low HbA1c levels. Therefore, interpreting quality of glucose control via HbA1c measurement under ribavirin containing treatment is not encouraged in patients with diabetes.