Glycated hemoglobin (HbA1c or A1c) is a good tool for evaluating blood glucose control results. The American Diabetes Association (ADA) recommends that diabetes patients be tested twice a year when their blood glucose is controlled and stable. Patients who do not have good blood glucose control should be tested once a quarter. Patients do not need to be tested on an empty stomach.

The testing principle for HbA1c uses the glycated action of glucose on red blood cells to detect blood glucose. Higher blood glucose concentration corresponds to higher glycated action. The life of a red blood cell is about 90 to 120 days. Thus, this reflects the blood glucose control status of the patient for the past 2 to 3 months. The ADA recommended that the ideal HbA1c control target for blood glucose of non-pregnant adults with diabetes is less than 7%. The better the HbA1c control, the more effective the prevention or delay in occurrence of complications. However, the control target should still be individualized (set different control targets) according to the patient’s age, whether or not there are complications, and whether or not there is occurrence of low blood glucose.

In addition to evaluating blood glucose control results, HbA1c can also be used for diagnostic purposes after passing NGSP certification. When HbA1c is higher than 6.5%, and repeated testing shows that it is still higher than 6.5%, then the patient is considered to be diagnosed with diabetes.