Abbreviation: HbA1c
The concentration of glycated hemoglobin A1 in red blood cells. In an nonenzymatic reaction (glycation), glucose in the blood binds to hemoglobin and forms HbA1c. The higher the blood glucose levels, the more HbA1c is detectable. Therefore, the percentage of HbA1c in the blood serves as a surrogate parameter for the average blood glucose level over the life span of red blood cells (~ 3 months) and can be used to diagnose diabetes mellitus and monitor response to treatment.