Reviewed by Brunilda Nazario on June 06, 2012

Sources

C. Ronald Kahn, MD - President / Director, Joslin Diabetes Center; Mary K Iacocca Professor of Medicine, Harvard Medical School. His discoveries in insulin signals/receptors revolutionized diabetes research.

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Video Transcript

C. Ronald Kahn, M.D. President and Director, Joslin Diabetes Center: What is the A1c blood test? The hemoglobin A1C test is a measure of what we call long term glucose control. The way this works is that sugar in your body is going up and down all day long whether you have diabetes or you don't have diabetes. And so when we measure our blood sugar what we're doing is getting a snapshot of that moment in time.

C. Ronald Kahn, M.D. President and Director, Joslin Diabetes Center: For people with diabetes, we also want to know what's happened in average over weeks or months of time. And the way the hemoglobin A1C test works is it measures the amount of the sugar that's attached to the protein in red blood cells, hemoglobin. And this measures really on average how is your blood sugar been for about 60 days or 70 days, cause that's how long the red blood cells last in your body.

C. Ronald Kahn, M.D. President and Director, Joslin Diabetes Center: So, we use both the blood sugar test, whether it's a fasting or after meal blood sugar test, and a hemoglobin A1C, one to get the short term picture and one to get the long term picture.