Which statement about HbA1c in acute settings is true?

• A. HbA1c measures long-term glycemic control and is not appropriate for acute glucose assessment
• B. HbA1c measures current glucose level in the ED
• C. HbA1c should be used to guide immediate insulin dosing
• D. HbA1c is unaffected by red cell turnover

Answer: (A)

HbA1c reflects average blood glucose over the past two to three months because glucose binds permanently to hemoglobin as red cells circulate. In acute care, decisions hinge on current glucose levels to prevent immediate harm, so HbA1c isn’t suitable for guiding urgent management. It’s useful for assessing long-term glycemic control and complication risk, not for immediate insulin dosing. HbA1c can be influenced by red cell turnover: shorter red cell lifespan tends to lower HbA1c, while longer lifespan can raise it, independent of current glucose. So the statement that HbA1c measures long-term glycemic control and is not appropriate for acute glucose assessment is the correct one.