HbA1c

HbA1c (glycated hemoglobin) reflects the proportion of hemoglobin stably bound to glucose, providing an integrated estimate of average blood glucose over approximately the prior 2 to 3 months, with the most recent ~30 days contributing roughly half of the signal per published kinetic models. It is the primary biomarker for diagnosing and monitoring type 2 diabetes (threshold 6.5%) and prediabetes (5.7 to 6.4%). HbA1c is influenced by erythrocyte lifespan, anemia, and hemoglobin variants.