Posted on 07/02/2009 12:12:52 AM PDT by neverdem
NEW ORLEANS — An international committee of experts has endorsed the use of the hemoglobin A1c assay to diagnose diabetes, at a level of 6.5% or above.
The 21-member international committee, chaired by Dr. David M. Nathan, was appointed by the American Diabetes Association (ADA), the European Association for the Study of Diabetes (EASD), and the International Diabetes Federation (IDF). Their consensus report—presented in a symposium at the annual scientific sessions of the American Diabetes Association and published simultaneously online in Diabetes Care—has not yet been officially endorsed by the three organizations.
“This is the first major departure from the way that we've been diagnosing diabetes for more than 30 years,” Dr. Nathan, director of the diabetes center at Massachusetts General Hospital and professor of medicine at Harvard Medical School, Boston, said at a press briefing held during the ADA meeting.
Since 1997, the cut-offs for diagnosing diabetes with either the fasting plasma glucose (FPG) or the 2-hour oral glucose tolerance test (OGTT) have been based on the risk for developing retinopathy. The committee reviewed available data and determined that the HbA1c assay was a better measure of that risk for several reasons.
HbA1c is a more stable analyte than is glucose. And importantly, HbA1c is more convenient as it does not require an 8-hour fast or a test that takes 2 hours. “It also correlated very tightly with the risk for developing retinopathy,” Dr. Nathan said.
The panel also advised that people with HbA1c values between 6.0% and 6.5% be considered at high risk for diabetes. However, they said that the term “prediabetes” is misleading because not everyone who meets those cut-offs will progress to diabetes, and some who are below the cut-offs will.
The document is only a consensus statement at this point, Dr. Paul Robertson, ADA president, emphasized. The ADA will now refer the paper to a practice group, which will review it to determine the medical, social, financial, worldwide, and other implications for changing the diagnostic criteria for diabetes, said Dr. Robertson, professor of medicine at the University of Washington, Seattle.
The document specifies the following for the diagnosis of diabetes:
▸ Diabetes should be diagnosed when HbA1c is at least 6.5%. Diagnosis should be confirmed with a repeat HbA1c test. Confirmation is not required in symptomatic subjects with plasma glucose levels above 200 mg/dL.
▸ If HbA1c testing is not possible, previously recommended diagnostic measures such as the FPG or 2-hour OGTT are acceptable.
▸ In children and adolescents, HbA1c testing is indicated when diabetes is suspected in the absence of both classical symptoms and a casual plasma glucose concentration above 200 mg/dL.
For the identification of those at high risk for diabetes:
▸ The risk for diabetes based on levels of glycemia is on a continuum. Therefore, there is no lower glycemic threshold at which risk clearly begins.
▸ The categorical clinical states of prediabetes, impaired fasting glucose, and impaired glucose tolerance fail to capture the continuum of risk and will be phased out.
▸ The HbA1c assay has several advantages over laboratory measurements of glucose in identifying individuals at high risk for developing diabetes.
▸ Those with HbA1c levels below the threshold for diabetes but at least 6.0% should receive demonstrably effective preventive interventions. Those with HbA1c below this range may still be at risk and, depending on the presence of other diabetes risk factors, may also benefit from prevention efforts.
▸ The HbA1c level at which population-based prevention services begin should be based on the nature of the intervention, the resources available, and the size of the affected population.
“To much of the medical community of America, this will not come as a surprise,” noted Dr. Richard Kahn, chief scientific officer of the ADA. “Many physicians are already using HbA1c with their own cutpoints for diabetes.”
Im a type 1 of nearly 40 years (I’m 48). I test 4 times a day and take insulin before each mean and a long acting at night. Last A1c was 6.0 first time in 2 years I’ve had one that high. Am curently working on getting insurance to pay for both a pump and a contant glucose monitor for even better living.
That depends - does a compulsive need to understand things mean I educate myself?
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