Dr. Michael Bergman, Clinical Associate Professor in the NYU Division of Endocrinology, Diabetes, and Metabolism appeared recently on ABC-TV to discuss an effective new test for diabetes, the "A1C" test, also known as the "glycated hemoglobin" or "HbA1c."
The hemoglobin A1c assay averages blood glucose levels for approximately 3 months and has therefore long been used for assessing diabetes control given the fluctuations inherent with blood glucose measurements. An International Expert Committee has very recently recommended that the hemoglobin A1C can be now used for diagnosing diabetes as it is less variable and represents a better index of control than glucose levels, does not require fasting, and the A1C test is standardized. However, it may not be reliable in pregnancy or in the presence of certain anemias, blood loss, transfusions, or abnormal hemoglobin traits (such as sickle cell disease).
The diagnosis of diabetes is made if the A1C level is equal to or greater than 6.5%. Diagnosis should be confirmed with a repeat A1C test unless clinical symptoms and glucose levels greater than 200 mg/dl are present. Individuals with an A1C level greater than or equal to 6% but less than 6.5% are likely at the highest risk for progression to diabetes but this range should not be considered an absolute threshold at which preventative measures are initiated. Those with A1C below 6% may still be at risk and depending on the presence of other diabetes risk factors may also benefit from prevention efforts.