A1C

A1C: A test that measures how much glucose has been sticking during the past 3–4 months to hemoglobin, the substance in the red blood cells that carries oxygen to the cells of the body. The A1C test is important in diabetes as a long-term measure of control over blood glucose. Even outside of diabetes, an elevated A1C level may be a cardiovascular risk factor.

For more information about A1C, see: Hemoglobin A1C.