Hemoglobin A1c Test

What is the hemoglobin A1c test?

The hemoglobin A1c test is a blood test used in the care of people who have diabetes. Hemoglobin A1c is a chemical combination of hemoglobin and glucose. Hemoglobin is the part of the red blood cells that carries oxygen. Glucose is a type of sugar in the blood.

The hemoglobin A1c percentage rises as the average blood sugar level rises. Sugar absorbed from the digestive system circulates in the bloodstream. Some of the sugar combines with the hemoglobin in red blood cells to form hemoglobin A1c. As more sugar circulates in the bloodstream, more hemoglobin gets changed into hemoglobin A1c.

Red blood cells live 90 to 120 days. Once sugar has combined with the hemoglobin, it stays that way for the rest of the life of the red blood cell. This means the amount of hemoglobin A1c in your blood reflects the average sugar concentration in your blood over a 3-month period.

Why is this test done?

Hemoglobin A1c is an excellent way to check how well blood sugar is being controlled over a 3-month period.

Hemoglobin A1c measurements are important for at least two reasons. The first is that they confirm daily home blood sugar monitoring results. The second is that there appears to be a direct relationship between the hemoglobin A1c level and the risk of diabetic complications. In other words, the higher the hemoglobin A1c percentage, the greater the risk of developing diabetic eye, kidney, or nervous system disease.

How do I prepare my child for this test?

No preparation is necessary except to prepare for the pain of a blood draw. One of the advantages of this test is that fasting is not necessary before the test.

How is the test done?

A small tube of blood is taken from your child's arm through a needle.

How will I get the test result?

Ask your child's health care provider when you can learn the results. Ask whether you should call for the results or whether the provider will call you.

What does the test result mean?

Hemoglobin A1c percentages in children should be and usually are somewhat higher than for adults. For childhood diabetics the results are usually judged as follows:

• For age less than 8 years, A1c < 9 % means good control.
• For age of 8 years or older, A1c < 8 % means good control.

What if my child's test result is not normal?

If your child has been diagnosed as diabetic and his or her test is not normal, the health care provider will talk to you about how to lower your child's blood sugar through diet, exercise, or medicine. Maintaining blood sugar levels and hemoglobin A1c levels in or near normal ranges will help your child avoid the complications of diabetes.