diagnosticEstablished
Diabetes mellitus
Glycated hemoglobin is an established diagnostic and monitoring biomarker for diabetes, reflecting average glycemia over the preceding two to three months.1
Glycome Atlas
Loading reviewed Atlas content…
Glycome Atlas
concept
Also known as glycated hemoglobin, A1c, glycosylated hemoglobin
Plain-language answer
HbA1c is a blood test that measures how much sugar has stuck to hemoglobin, the protein inside red blood cells that carries oxygen. Because red blood cells live for about three months, the amount of sugar attached to them reflects the average blood sugar over that period, not just the level on the day of the test.12
HbA1c gives a stable snapshot of long-term blood sugar control, which is why it is used to diagnose and monitor diabetes. A higher value means more sustained exposure to high glucose, which is tied to a greater risk of complications in the eyes, kidneys, nerves, and blood vessels.1
Technical detail
HbA1c is the fraction of hemoglobin bearing a stable Amadori-type glucose adduct on the N-terminal valine of the beta chain, an established glycation biomarker whose level integrates ambient glycemia over the roughly 8 to 12 week lifespan of the erythrocyte.1
Glucose enters erythrocytes and condenses non-enzymatically with the N-terminal valine of the hemoglobin beta chain, forming a Schiff base that rearranges to a stable Amadori ketoamine. Because the modification is essentially irreversible over the cell's lifetime and accumulates in proportion to ambient glucose, the measured percentage integrates glycemic exposure across the preceding two to three months.1
HbA1c is a standardized, widely used clinical assay for diagnosing diabetes and monitoring long-term glycemic control, and higher values track with greater risk of chronic diabetic complications. Unlike research measurements of specific advanced glycation end products, it is a routine laboratory test with harmonized reference standards.1
Human relevance
Glycated hemoglobin is an established diagnostic and monitoring biomarker for diabetes, reflecting average glycemia over the preceding two to three months.1
Higher HbA1c reflects greater cumulative glucose exposure and is associated with increased risk of the microvascular and cardiovascular complications of chronic hyperglycemia.1
Continue exploring
References