THEglycated hemoglobin ou glycosylée (sometimes referred to as HbA1c) is a special form of hemoglobin, the pigment found in Red cells which allows to transport theoxygen in the blood. Thus, glycated hemoglobin is a hemoglobin on which a molecule of glucose. There is a proportional relationship between the level of HbA1c and the level of blood glucose. The higher the percentage of glycated hemoglobin in the blood, the higher the average blood sugar level (blood glucose level).

The glycated hemoglobin assay is therefore used for monitoring people with diabetes, in addition to the blood sugar assay. Blood sugar reflects the instantaneous sugar level in the blood, while the glycated hemoglobin level reflects the overall balance of diabetes, that is, its degree of control. If the HbA1c is too high, it is a sign that the diabetes is not well controlled and that the treatments must be adjusted.

The glycated hemoglobin is assayed by blood test in a medical analysis laboratory. It is recommended at regular intervals, approximately every 2 to 3 months (4 times a year according to the Haute Autorité de Santé in France).

It is not necessary to be fasting for the blood test.

The determination of the HbA1c is given as a percentage. In people without diabetes, this percentage is between 4% and 6%.

In people with type 2 diabetes, recommended goals are set with the doctor. According to the recommendations of the health authorities, the target glycated hemoglobin should generally be less than 7%. If this is not the case, the drug treatment should be re-evaluated.

For some diabetic patients, for example with complications or advanced age, the HbA1c targets may vary, however.