Decline in Hemoglobin A1c in Diabetic Patients Treated for Hepatitis C

Hemoglobin A1c (also known as glycosylated hemoglobin) is a cumulative measure of an individual's blood glucose levels over the past 2-3 months. It is typically used to help diabetics monitor whether they are keeping their blood sugar under control.

Hemoglobin A1c levels are often lower in patients with hemolysis, a condition characterized by destruction of red blood cells, due to shorter exposure of hemoglobin to plasma glucose.

Because ribavirin used to treat chronic hepatitis C is known to cause reversible hemolytic anemia, researchers with the Bronx Veterans Affairs Medical Center conducted a study to examine the extent to which ribavirin treatment influences hemoglobin A1c levels in diabetic patients with HCV.

As described in the September 2006 Journal of Viral Hepatitis, the researchers performed a retrospective analysis that identified 32 diabetic patients who underwent hepatitis C treatment with interferon plus ribavirin. Each subject had at least 3 measures of hemoglobin A1c, hemoglobin (Hb), and glucose before, during, and after therapy.

Results

A1c values decreased from a mean pretreatment level of 7.2% to 5.2% during ribavirin treatment (mean paired difference -2.01%; P < 0.001).

During therapy, mean Hb levels decreased from 15.1 g/dL at baseline to a nadir (lowest ever) level of 11.7 g/dL (P < 0.001).

Lactose dehydrogenase levels and reticulocyte counts rose, while mean corpuscular volume values remained unchanged, confirming the presence of hemolysis.

At the same time, glucose levels declined by a mean of 38.4 mg/dL (P = 0.002).

Body weight decreased by a mean of 3.15 kg (P < 0.001).

According to published correlation tables, a decline in glucose concentration of 38.4 mg/dL correlates to an A1c decline of 1.08%.

Conclusion

In conclusion, the authors wrote, "reductions of A1c levels by a mean of 2.01% during hepatitis C therapy with interferon plus ribavirin are due to a combination of decreased glucose levels (1.08%) and ribavirin-induced hemolysis (0.93%)."

They recommended that, "A1c levels should not be measured during hepatitis C treatment with interferon plus ribavirin because they do not adequately reflect glycemic control."

9/19/06

Reference
P D Greenberg, A S Rosman, L S Eldeiry, and others. Decline in haemoglobin A1c values in diabetic patients receiving interferon-alpha and ribavirin for chronic hepatitis C. Journal of Viral Hepatitis 13(9): 613-617. September 2006.