Glycated hemoglobin - a mandatory test for the diagnosis of diabetes and evaluation of its level of compensation

In medical practice, there are cases when it is difficult to assess the effectiveness of hypoglycemic drugs and the adequacy of prescribed treatment in patients with diabetes. It seems that a person feels well, and glucose on an empty stomach is within normal limits, but what is the probability of complications in this patient? After all, the amount of glucose in the blood is assessed only at the time of the study, this indicator is single.

Sometimes the increase in glucose in the blood is also found in healthy people, for example, after taking a lot of carbohydrates or with excessive mental and emotional stress. The level of sugar can affect the intake of certain medications, such as oral contraceptives, some diuretics, psychotropic drugs. In all the difficult cases, an analysis for glycated hemoglobin comes to the aid of the endocrinologist, in the direction of the study it is designated as HbA1c.

Glycated hemoglobin is an emerging compound of glucose and hemoglobin A molecules, normally this process occurs constantly in healthy people. The amount of hemoglobin undergoing glycation is 5-8%. In patients with diabetes, this indicator increases by 2-3 times and persists throughout the life of the erythrocyte, i.e. 120 days. Since both young and mature red corpuscles are present in the blood, the average age of the erythrocyte, which is equal to the half-life of its life-60 days, is taken.

Glycated hemoglobin, whose norm is 4-6.1% of the total hemoglobin level, shows an average glucose content for two months prior to the time of the blood test. Therefore, it can be determined whether there was a long-term increase in glucose or for 2 months this indicator was in the normal state. The correlation between HbA1c and glucose in the blood has been proved by many years of research, it has been empirically established that the increase in blood glucose by 1.59 mmol / l corresponds to 1% of hemoglobin subjected to glycation.

In what cases is an analysis done for glycated hemoglobin?

- for the diagnosis of diabetes mellitus and the level of its compensation;

- for control of treatment with sugar-reducing drugs ;

- to determine the risk of vascular complications in diabetes;

- in all cases of violation of glucose tolerance and diagnosis of prediabetes;

- Pregnant women with a risk of developing diabetes.

Interpretation of the results of the analysis with diabetes:

Up to 5.8% - diabetes is well compensated.

From 8 to 10% - partially compensated diabetes.

Over 12% is a poorly compensated disease.

Endocrinologists try to select therapy so that glycated hemoglobin is in the range of 7 to 8%. With adequately prescribed treatment, elevated HbA1c levels recover to normal after one month of adjustment.

The American Diabetes Association recommends that the study be conducted at least once every 6 months. In Russia, HbA1c analysis is prescribed for all patients receiving insulin and hypoglycemic medications, once every 3 months. By the level of hemoglobin HbA1c it can be judged whether the probability of the patient developing the pathology of retinal microvessels, kidneys and damage to nerve fibers is high.

In what cases is the distortion of the analysis possible on HbA1c?

A false increase in the results is observed with an increase in the level of fetal hemoglobin in the blood and in iron deficiency anemia. A false decrease in the indices is revealed when erythrocytes are destroyed due to haemolysis, after a blood transfusion or massive blood loss.

The analysis for hemoglobin glycated is prescribed a little more often (once a month) for patients who have a non-standard course of the disease, if they have severe concomitant pathology, pregnant women with diabetes mellitus to prevent the development of pathology in the fetus.