What HbA1c value defines diabetes according to current guidelines?

• A. HbA1c ≥ 6.5%
• B. HbA1c ≥ 7.0%
• C. HbA1c ≥ 5.7%
• D. HbA1c ≥ 6.0%

Answer: (A)

Measured HbA1c reflects the average blood glucose over roughly the past 2–3 months, since it measures how much glucose has attached to hemoglobin in red blood cells. Using 6.5% as a threshold aligns with data showing a meaningful rise in microvascular complication risk, particularly retinopathy, above that level. That makes 6.5% or higher the point at which diabetes is diagnosed. Values between 5.7% and 6.4% are considered prediabetes, indicating increased risk but not yet diabetes. A single HbA1c of 6.5% or higher can diagnose diabetes, though repeating the test on a different day is often advised unless there are clear hyperglycemia symptoms. Be mindful that factors like certain anemia, hemoglobin variants, or ethnic differences can affect HbA1c results, so clinical context is important.