Which test provides an estimate of long-term glycemic control by measuring glucose-bound hemoglobin?

Which test provides an estimate of long-term glycemic control by measuring glucose-bound hemoglobin?

• A. Serum glucose level
• B. Glycosylated hemoglobin
• C. Blood pH
• D. Serum protein

Answer: (B)

Long-term glycemic control is best estimated by measuring glycated hemoglobin, because glucose attaches to hemoglobin over the lifespan of red blood cells (about 120 days). The amount of glucose-bound hemoglobin accumulates in proportion to average blood glucose, so the HbA1c value reflects how well blood sugar has been controlled over roughly the past 2–3 months rather than just a single moment in time. This makes it the preferred test for monitoring diabetes management and guiding treatment changes. A serum glucose level shows the current glucose level, not long-term exposure. Blood pH indicates acid-base status, and serum protein levels do not track glucose control over time. Higher HbA1c means poorer control, with individual targets varying by patient.

Long-term glycemic control is best estimated by measuring glycated hemoglobin, because glucose attaches to hemoglobin over the lifespan of red blood cells (about 120 days). The amount of glucose-bound hemoglobin accumulates in proportion to average blood glucose, so the HbA1c value reflects how well blood sugar has been controlled over roughly the past 2–3 months rather than just a single moment in time. This makes it the preferred test for monitoring diabetes management and guiding treatment changes. A serum glucose level shows the current glucose level, not long-term exposure. Blood pH indicates acid-base status, and serum protein levels do not track glucose control over time. Higher HbA1c means poorer control, with individual targets varying by patient.