Guidelines May Soon Include A1C As Diagnostic Test


The A1C test has been used for many years to monitor blood sugar in diabetic patients. Many of the leading diabetes organizations are working on new guidelines that will be published later this year. Consensus of the groups could recommend the A1C test as a tool for diagnosing the type 2 diabetes.

Currently there is no criteria for using A1C as a diagnosis tool, but many doctors use it in their practices for diagnosing type 2 diabetes.

The ADA guidelines currently recommend doctors use the fasting blood glucose (FBG) test in patients who are at risk for type 2 diabetes. A less common practice is for doctors to require an oral glucose tolerance test (OGTT). Both of these methods are sensitive at measuring real-time glucose levels in the blood. However, both of these methods are also easily thrown off, for example, if a person has a cold or hasn't eaten properly.


The benefit of the A1C test is that it can be taken at any time of day and is not thrown off by events of the day. Most likely, it probably would be used along with other tests.

A1C is also called the HbA1c or glycated hemoglobin test. This test 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 6, that means 6% of your hemoglobin molecules are glycated. People who don't have diabetes typically have about a 6 or less reading. Higher results may indicate diabetes.

Once diagnosed with diabetes, A1C level is used to watch your overall glucose control. The level should be measured at least twice a year. It may need to be done more often, if you are newly diagnosed or starting a new medication or your control has been poor.

American Diabetes Association
American Association of Clinical Endocrinologists



Dr. Bates, Thank you for an excellent patient education article about glycated hemoglobin. We write extensively about A1C and its importance as a marker in the links between type2 diabetes and gum disease - Charles Martin, DDS Founder, Dentistry For Diabetics