Diabetes blood sugar test now recommended for diagnosis

[Islander]

8 June 2009
By Mary Brophy Marcus, USA TODAY


A blood test physicians use regularly to check blood sugar levels in people with diabetes is now being recommended as a tool to diagnose the disease.
At the American Diabetes Association's 69th annual meeting in New Orleans today, an international committee of experts announced their consensus that the A1C assay is an accurate way to diagnose diabetes in adults and children, but not in pregnant women.

FIRST REPORT: Considerations in adopting A1C as diagnostic tool
"This is a major departure from the way diabetes has been diagnosed in the past," says David Nathan, director of the Diabetes Center at Massachusetts General Hospital. and professor of medicine at Harvard Medical School. Nathan also is chair of the 21-person committee that included scientists from the ADA, the International Diabetes Federation (IDF), and the European Association for the Study of Diabetes (EASD), and that conducted an extensive evaluation of A1C scientific literature over recent months.
For decades, diabetes has been diagnosed by using either a fasting plasma glucose (FPG) test or the less commonly employed oral glucose tolerance test (OGTT). Both are recommended by the ADA and capture the person's glucose level as it exists at the time the test is given.
FIND MORE STORIES IN: Massachusetts General Hospital
The two tests are sensitive but results can be thrown off by many factors, including eating before the test and illness, says Nathan.
The A1C test, which measures average blood glucose levels over the preceding two to three months, is easier on patients, say clinicians. It is not thrown off by events of the day, Nathan says. And where the FPG and OGTT involve fasting, the A1C requires only a simple blood draw that can be done any time of day without skipping food.
Also called the HbA1c or glycated hemoglobin test, it tells what your average blood glucose level was over the past two or three months by measuring the concentration of hemoglobin molecules in your red blood cells that have glucose attached to them.
Once glycated, or sugar-coated, the hemoglobin stays that way throughout the red blood cell's life span, which is about 120 days. So, if your A1C is an 8, that means 8% of your hemoglobin molecules are glycated. People who don't have diabetes typically have a reading of about a 6 or less. Higher results may indicate diabetes.
The only thing that has kept the reliable test from becoming a standard diagnostic tool is that the major diabetes groups have not yet agreed on what result constitutes a diagnosis. Nathan says the international committee advises that anyone with a reading of 6.5% or greater should be considered diabetic.
He says the A1C is also a more accurate predictor of a person's likelihood of developing disease-related complications, including nerve damage, vision problems, and cardiovascular disease.
The recommendations are not officially endorsed by the ADA, which will do its own independent evaluation based on the new recommendations, says Richard Kahn, chief scientific and medical officer of the ADA.
Kahn also stresses that the A1C does not replace the other diagnostic methods. "The existing tests are perfectly satisfactory. The committee is saying this is preferable to do. But for those who don't have equipment or where the test isn't standardized, the other tests are fine," says Kahn.

http://tinyurl.com/m84qbl

[Islander]

This seems obvious to me. Can't understand why it hasn't been the standard all along.

Oh, and re: "anyone with a reading of 6.5% or greater should be considered diabetic."...

My latest A1C, taken last week, was 5.9. Technically, I have not been diabetic for about 9 months!

[Reesacat]

Agree with Islander-the A1C test measures your average blood sugar over a couple/three months. A single blood sugar reading might not pick up diabetes (if you didn't eat for 8-12 hours it could be normal even if you were diabetic).

An explaination and chart of what the A1C test translates to daily blood sugars:
http://www.dlife.com/dLife/do/ShowCo...onversion.html