Hemoglobin is found inside red blood cells. Its job is to carry oxygen from the lungs to all the cells of the body. Hemoglobin, like all proteins, links up with sugars such as glucose.
You know that when you have uncontrolled diabetes you have too much sugar in your bloodstream. This extra glucose enters your red blood cells and links up (or glycates) with molecules of hemoglobin. The more excess glucose in your blood, the more hemoglobin gets glycated. It is possible to measure the percentage of A1C in the blood. The result is an overview of your average blood glucose control for the past few months.
There is a correlation between A1c levels and average blood sugar levels as follows:
While there are no guidelines to use A1c as a screening tool, it gives a physician a good idea that someone is diabetic if the value is elevated. Right now, it is used as a standard tool to determine blood sugar control in patients known to have diabetes.
A1c(%)
Mean blood sugar (mg/dl)
6
135
7
170
8
205
9
240
10
275
11
310
12
345
The American Diabetes Association currently recommends an A1c goal of less than 7.0%, while other groups such as the American Association of Clinical Endocrinologists recommend a goal of less than 6.5%.
Of interest, studies have shown that there is a 10% decrease in relative risk for every 1% eduction in A1c. So, if a patients starts off with an A1c of 10.7 and drops to 8.2, though there are not yet at goal, they have managed to decrease their risk of microvascular complications by about 20%. The closer to normal the A1c, the lower the absolute risk for microvascular complications.
