The A1C test is the primary test used for diabetes diagnosis and management. However, it may not be the best test to use in African Americans—particularly those with sickle cell trait.
What is the AIC?
The A1C test—also called the hemoglobin A1c, HbA1c, or glycohemoglobin test—shows how much glucose is attached to hemoglobin, the protein in red blood cells that carries oxygen. Typically, red blood cells live for about three months. So, the A1C test is reflective of your average blood glucose (blood sugar) level over the past three months.
The A1C test is different from the blood glucose checks that you do every day—also known as self-monitoring of blood glucose (SMBG). It is important to keep in mind that each blood glucose result from SMBG provides information for only one point in time. You and your doctor need to use both the AIC and SMBG results to get a complete picture of your blood glucose control. The higher your A1C number, the higher your blood glucose levels have been during the past three months. Elevated levels of blood glucose can harm your heart, blood vessels, kidneys, feet and eyes.
A1C Test and African Americans
There are racial differences that your doctor should consider when using the A1C test results.
According to a study presented at the American Diabetes Association 76th Scientific Session, researchers found that glucose attaches to the red blood cell at a higher rate in African Americans than in Whites. For the same blood glucose level, the A1C was about 0.3 percent higher in African Americans than in Whites. In other words, for the same glucose level, an African American woman would have an A1C of 8 percent, but the White woman would have an A1C of only 7.7 percent.