Hemoglobin A1C Test

What is the hemoglobin A1C test?

The hemoglobin A1C ("A-one-C") test is a blood test used in the care of people who have diabetes. The hemoglobin A1C test is a way of looking at your child's average blood sugar control over a period of 2 or 3 months.

Sugar absorbed from the digestive system circulates in the bloodstream. When the blood sugar is high, the sugar attaches to the hemoglobin protein in red blood cells, forming hemoglobin A1C.

Red blood cells live 90 to 120 days. This means that once sugar has combined with the hemoglobin in red blood cells, the hemoglobin A1C stays in the blood for 90 to 120 days. This means the amount of A1C in your child's blood reflects how high the blood sugar has been over the past 3 months and how often it has been high.

Why is this test done?

A1C is an excellent way to check how well blood sugar is being controlled over a 3-month period.

A1C measurements are important because:

• They confirm your child's daily home blood sugar results and testing schedule.
• They help predict your child's risk of diabetic complications. The higher the A1C percentage, the greater the risk of developing diabetic eye, kidney, cardiovascular, and nervous system disease.

How do I prepare my child for this test?

No preparation is necessary. One of the advantages of this test is that your child does not need to fast before having the test.

How is the test done?

Your child's healthcare provider will poke a finger with a lancet and fill a small tube with the blood. Sometimes blood is taken from your child's arm through a needle instead of using a finger poke.

At some pharmacies you may be able to buy a device that allows you to test A1C at home. You may find that the results of the home test are not the same as results of tests done at your provider's office.

How will I get the test result?

Ask your child's healthcare provider when and how you will get the result of your child’s test.

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 6 years, A1C of 7.5% to 8.5% means good control.
• For age of 6 to 12 years, A1C under 8% means good control.
• For age of 13 to 19 years, A1C under 7.5% means good control.

The following chart shows examples of how the A1C is related to average blood sugar level:

 A1C    Estimated Average Blood Glucose (eAG)
---------------------------------------------
  6%         126 mg/dL (7.0 mmol/L)
  7%         154 mg/dL (8.6 mmol/L)
  8%         183 mg/dL (10.2 mmol/L)
  9%         212 mg/dL (11.8 mmol/L)
 10%         240 mg/dL (13.4 mmol/L)
---------------------------------------------

Remember that, even though your child has this test every few months, you need to keep testing your child’s blood sugar as often as your provider recommends.

Previously the hemoglobin A1C was reported only as the percentage. Now it will also be available from most labs as the eAG, or estimated average glucose. If you know your child’s A1C, you can use the chart above to know what your child’s average blood glucose has been. Many healthcare providers will soon be reporting results as both the A1C percentage and the actual average blood sugar.

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 healthcare provider will talk to you about how to lower your child's blood sugar through diet, exercise, or medicine. Keeping blood sugar levels and A1C levels in or near normal ranges will help your child avoid the complications of diabetes.

If your child’s test results are not normal, ask your healthcare provider:

• if your child needs additional tests
• what to do to work toward a normal value
• when your child needs to be tested again.