Hemoglobin A1c measures:

A Immediate blood glucose

B Average blood glucose over the preceding 2-3 months based on glycated hemoglobin percentage

C Fasting glucose only

D Insulin levels

✓ Correct Answer: Option B

HbA1c: reflects average glycemia over 2-3 months (RBC lifespan ~120 days). <5.7% normal, 5.7-6.4% prediabetes, ≥6.5% diabetes. Target <7% for most diabetics (ADA). Falsely altered by hemoglobinopathies.

💡 Why is B) the correct answer?

The correct answer to the question "Hemoglobin A1c measures:" is Option B: Average blood glucose over the preceding 2-3 months based on glycated hemoglobin percentage.

The other options — A) Immediate blood glucose, C) Fasting glucose only, D) Insulin levels — are incorrect for this USMLE Exam Prep question. As explained above: HbA1c: reflects average glycemia over 2-3 months (RBC lifespan ~120 days).

📚 About This USMLE Exam Prep Practice Question

This 2-level USMLE Exam Prep question from the Step 1 - Basic Sciences topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free USMLE Exam Prep practice test or use flashcards for spaced repetition review.

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Hemoglobin A1c measures:

✓ Correct Answer: Option B

📚 About This USMLE Exam Prep Practice Question

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