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Glycosylated hemoglobin
Last reviewed: 04.07.2025
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Reference values (norm) for the content of glycosylated hemoglobin (HbA 1c) in the blood are 4.0-5.2% of total hemoglobin.
HbA 1c is a glycosylated formof HbA present in erythrocytes. At elevated blood glucose concentrations, it enters into non-enzymatic interaction with plasma proteins to form Schiff bases, including hemoglobin. The degree of hemoglobin glycosylation depends on the concentration of glucose in the blood and the duration of contact of glucose with hemoglobin. Therefore, the amount of HbA 1cis proportional to the concentration of glucose and the duration of incubation (contact with erythrocytes). Measuring the concentration of HbA 1callows for a retrospective assessment of the level of hyperglycemia in diabetes mellitus. In fact, glycosylated hemoglobin consists of three components: HbA 1a, HbA 1b and HbA 1c. HbA 1c has a higher correlation with the degree of hyperglycemia in patients with diabetes mellitus .
The concentration of HbA 1c in erythrocytes is an integral indicator of the state of carbohydrate metabolism over the previous 6-8 weeks. The results of the study are assessed as follows: 4-6% - good compensation of diabetes mellitus in the last 1-1.5 months, 6.2-7.5% - satisfactory, more than 7.5% - unsatisfactory. To assess the effectiveness of treatment, it is advisable to repeat the study after 2-3 months.
Falsely decreased HbA 1c values occur in uremia, acute and chronic hemorrhages, as well as in conditions accompanied by a decrease in the lifespan of red blood cells (for example, hemolytic anemia) .
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