In 2010, the American Diabetes Association released recommendations for the A1C test to be used to identify and diagnose diabetes. It is a blood test that gives health care providers a picture of how well the body metabolizes glucose over a three-month time frame.
Measures
The A1C test measures the average amount of sugar in the blood for the past two to three months. It measures how much of the hemoglobin, a part of red blood cells, has glucose (sugar) attached to it. With diabetes or a high risk of developing diabetes, the A1C test value is elevated.
How It Is Done
It is recommended to do the A1C test by a method that is certified by the National Glycohemoglobin Standardization Program, which is usually by blood draw. It is not recommended to use a point of care or finger stick A1C test, since those tests are not very accurate. The A1C test can be done at any time of the day, and the individual can eat and drink the day of the test.
Values
The American Diabetes Association defines an A1C test result between 5.7 and 6.4 percent as having a high risk of developing diabetes, while having an A1C test result of 6.5 percent or greater as having diabetes. A normal A1C value is a test result of 5.6 percent or lower.
Limitations
The A1C test may not work for people who may have anemia or low levels of iron, chronic or heavy bleeding, or if the blood has an uncommon type of hemoglobin. In these instances there may be other A1C tests that can be used or other blood glucose tests available to check for diabetes.
Significance
For those who have diabetes, the A1C test is very useful to health care providers in determining how well medications, diet and activity are working to help control blood glucose levels. For diabetics, the A1C test is done at least twice a year, and the goal is to have an A1C test value of 7 percent or less.
References
- Mayo Clinic: A1C test
- “Diabetes Care”; Diagnosis and Classification of Diabetes Mellitus; American Diabetes Association; January 2010
- National Diabetes Education Program: Know Your Numbers
