A1C Recommended as Diagnostic Tool

New recommendations issued by the American Diabetes Association (ADA) call for the addition of the hemoglobin A1C, or A1C, test to the tools currently used to diagnose prediabetes and Type 2 diabetes. According to statistics from the Centers for Disease Control and Prevention, 57 million people in the United States have prediabetes, with 1.6 million newly diagnosed each year, while nearly 24 million people in the country have Type 2 diabetes, 5.7 million of them undiagnosed.


The A1C test, which involves having a small amount of blood drawn, looks at the concentration of red blood cells that have glucose molecules attached, reflecting the concentration of glucose in the blood. Because the red blood cells in a blood sample used for an A1c test are a mixture of cells of different ages, the test gives a “weighted” average of blood glucose control over the previous 2–3 months. An A1C level of less than 7% is the target for most people who have diabetes.

Based on the new recommendations, a result on the A1C of 5.7% to 6.4% would place a person’s blood glucose levels in the prediabetes range, while an A1C of 6.5% or higher would indicate diabetes. The A1C test would join the fasting plasma glucose, or FPG, test (which involves measuring the amount of glucose in a person’s blood after at least eight hours without food or drink) and the oral glucose tolerance test, or OGTT (which measures a person’s blood glucose response to the consumption of a glucose-rich drink after at least eight hours without food or drink) as diagnostic tools for diabetes and prediabetes.

According Richard M. Bergenstal, MD, President-Elect of the ADA for medicine and science, “We believe that use of the A1C, because it doesn’t require fasting, will encourage more people to get tested for Type 2 diabetes and help further reduce the number of people who are undiagnosed but living with this chronic and potentially life-threatening disease… Unlike many chronic diseases, Type 2 diabetes actually can be prevented, as long as lifestyle changes are made while blood glucose levels are still in the prediabetes range.”

For more information on the recommendations, read “American Diabetes Association’s New Clinical Practice Recommendations Promote A1c as Diagnostic Test for Diabetes and Pre-Diabetes” or see the ADA’s Clinical Practice Recommendations in Diabetes Care. And to learn more about A1C, check out the article“H-B-A-1-C: What It Is and Why It Matters.”

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  • Elisabeth Fluellen

    Before my diagnosis, I asked my doctor why they couldn’t use the A1c to diagnosis diabetes and he told me that insurance companies won’t pay for the test until a diagnosis is made first. It just seems to me, it would be a better test for placing you either in the pre or diabetic stage of the disease.

  • Diane Schell, RN, BSN CDE

    It’s about time! With what we now understand about T2DM, the FBS becomes inadequate for diagnosis (much too late). And I can’t imagine a patient who would agree to repeated blood tests required for a GTT. As mentioned in the article, catching more people in the pre-diabetes phase, we might improve lives and save resources.

  • David

    While it is true that the H-A1C test is “another” good indicator of long term blood glucose levels, I did not see any mention of the fact that there are certain people (I’m one unfortunately) whose tests are falsely elevated. There is a special blood test that exposes this tendency, which is not even done locally (Spokane). We had to send it to a lab in Salt Lake City for verification. Sorry I don’t know tha actual name of the test. But as an adult-onset Type 1, we are no longer paying strict attention to the A1C test.

  • Bob M.

    This is the type of things that really tick me off. This is just a way to sell more test strips and oral medications.

    Only two months ago I went and had my A1C test done. According to the test results, anything under 6 is determined to me a normal person. Now all of a sudden it is 5.7. Seems to me like someone is cooking the books. Keep the numbers as they were two weeks ago and I would agree with the change.

    Lower the numbers and it means nobody is looking out for us, only their own wallets.

    Stop the madness.

  • Janet

    I agree with David. Get more people on drugs. It was the same with blood pressure numbers and cholesterol levels. The drug companies need to be severely reprimanded, but unfortunately there’s no oversight.

  • Becky

    It’s about time. If the A1c test had been used as a diagnostic tool, I would have been diagnosed with diabetes in 1998. As it is, I was not diagnosed until 2005 with a high random test. I am now considered an adult onset type 1 with 4 insulin shots a day and no oral medications. However, because I did not test positive for antibodies (15% do not) I was first diagnosed type 2 and we fooled around with several treatments until somebody got wise and put me on insulin. I just wonder how much damage occurred before my current treatment began?

  • maggie

    Oh fgs! Science is an evolving thing and new research results means that the ways of doing things will shift as well. The testing and treatment of diabetes has changed dozens of times since I was diagnosed in 1985. While I was confused and irritated by the moving goal lines at first, now I realize that my medical care is getting better with these changes. I have more control.

    Not everything is a plot to sell more drugs. It is good to get more information about one’s condition and its management. Whether you buy the pills is up to you. Feel free to refuse, but know what the facts are.

  • Harold Hallock

    I would like to habe a copy of this info, or print it in your magazine.
    For some reason, I can not get my systom to
    print it.
    As I have said, your diabetes self-magament
    magazine has taught me more about diabetes
    than any of the doctors have!

    Thank you

  • Steven

    My last A1C was 5.6 % with a calculated average BG of 114. So a range of 5.7% to 6.4% to indicate pre diabetes seems reasonable to me.

    I don’t mind if the medical community tightens requirements for testing and diagnosis I think this helps all of us be more healthy. I do admit it is more difficult to reach these goals….

  • Dolores Richardson

    We should all be thankful that they have these test, My doctor told me as long as I keep the AlC below 7 I will not have other complications that go with diabetis, But that is hard for me to do most times. Luck to you all. Dolores

  • Nancy

    I find great displeasure with the statement that type 2 can be prevented. I was first diagnosed at age 12 but was not Type 1. I was diet controlled until age 51- did you get the hormone connection?
    So I have been diet controlled with daily exercise and being a very active person- the A1c’s didn’t actually begin for me until about 10 years ago- all the glucose tolerance always proved almost fatal and now the A1c are hard to maintain. I am a very healthy person and my PCP is not splitting fractions before making medication changes. My emotional wellbeing is surely tied to that A1c- and my PCP treats the total me.