Glycated hemoglobin is used to assess average plasma glucose over approximately how many months?

Glycated hemoglobin is used to assess average plasma glucose over approximately how many months?

• A. 1 month
• B. 2-3 months
• C. 6 months
• D. 12 months

Answer: (B)

Glycated hemoglobin reflects the time history of glucose exposure across the lifespan of red blood cells. Red blood cells circulate for about 120 days, and glucose attaches to hemoglobin gradually over that period. Because new cells replace old ones, the HbA1c value represents an integrated, rolling average of blood glucose for roughly the last two to three months, with more weight on the most recent weeks. That’s why the standard answer is about 2–3 months. If red blood cell turnover is altered (for example, in anemia or with transfusions), HbA1c accuracy can be affected.

Glycated hemoglobin reflects the time history of glucose exposure across the lifespan of red blood cells. Red blood cells circulate for about 120 days, and glucose attaches to hemoglobin gradually over that period. Because new cells replace old ones, the HbA1c value represents an integrated, rolling average of blood glucose for roughly the last two to three months, with more weight on the most recent weeks. That’s why the standard answer is about 2–3 months. If red blood cell turnover is altered (for example, in anemia or with transfusions), HbA1c accuracy can be affected.