People with type 2 diabetes and hepatitis C virus (HCV) who cure the virus tend to improve their blood sugar levels, specifically their hemoglobin A1c (HbA1c), and also reduce their insulin use.

Veterans Affairs researchers compared HbA1c among 2,435 people with diabetes who were recently treated for hep C for the first time, of whom 2,180 were cured and 255 were not.

Seventy-five percent of the individuals initially took at least one diabetes medication, and 42 percent took insulin.

Curing hep C was associated with a drop in HbA1c among those who started with a type 2 diabetes–defining level of greater than 7.2 percent. After adjusting the data for various factors, the researchers found that among participants who started with such a high HbA1c level, those cured of HCV experienced a greater decline of 0.34 percentage points compared with those who were not cured.

The proportion of individuals receiving insulin decreased among those cured of hep C (from 41.3 percent to 38 percent), while this proportion increased slightly among those who were not cured of the virus (from 49.8 percent to 51 percent). The decline in insulin use was more pronounced among those who had an HbA1c level of 7.2 percent or below prior to HCV treatment.

“Diabetic patients with HCV infection should consider antiviral treatment for their hepatitis C, not only for the benefits to the liver but also for potential benefits to their glycemic control,” says study author George Ioannou, MD, an associate professor of medicine at the University of Washington.