It is the average blood glucose level of the past 3 months. It is measured as a percentage.
What is the basis of HbA1c: The red cells in our blood contain a protein called hemoglobin. The glucose in the blood binds to hemoglobin forming glycosylated hemoglobin. The average life span of a red blood cell is 120 days so glycosylated Hb gives a measure of glucose in the blood over these 120 days. After that old cells die and are replaced by new cells and glucose then binds to new cells. At one time 5% of red blood cells bind to glucose in a normal person, hence the normal level of HbA1c is 5%.
When to check HbA1c: It is recommended to check HbA1c after every 3 months or later every 6 months when the blood glucose control becomes stable. This test gives an idea to your physician about your commitment to your diet and exercise plan, and whether your medicine is working well or not.
What are the limitations: This test does not replace your daily glucose check, and you cannot adjust your daily dose of insulin with this. If a patient’s hemoglobin is abnormally low( anemia) or high, it will give false results.
Targets: Normal level = 4.5-5.5% Prediabetes = 5.6-6.5% Diabetes => 6.5% Our target is to achieve 5.5 % in all patients so that they become equal to normal people in terms of HbA1c.