Which condition is associated with falsely lowering HbA1c in diabetics?

Which condition is associated with falsely lowering HbA1c in diabetics?

• A. Haemolytic anaemia
• B. Iron deficiency anaemia
• C. Chronic kidney disease
• D. Hyperglycemia

Answer: (A)

HbA1c reflects the average blood glucose over the life of red blood cells, about 120 days. Anything that shortens red cell lifespan means there’s less time for glucose to attach to hemoglobin, so HbA1c can read lower than the true average glucose. In haemolytic anaemia, red cells are destroyed more quickly, so the circulating population is younger and has less glycation overall, making HbA1c falsely low. Hyperglycemia would raise HbA1c, not lower it, so that option wouldn’t fit. Iron deficiency anaemia tends to slow red cell turnover and can falsely elevate HbA1c, while CKD can affect HbA1c accuracy through factors like anemia and transfusions but doesn’t classically cause a false low in the same way as haemolysis. If HbA1c seems discordant with glucose readings, consider alternative measures such as fructosamine or glycated albumin, or use continuous glucose monitoring.

HbA1c reflects the average blood glucose over the life of red blood cells, about 120 days. Anything that shortens red cell lifespan means there’s less time for glucose to attach to hemoglobin, so HbA1c can read lower than the true average glucose. In haemolytic anaemia, red cells are destroyed more quickly, so the circulating population is younger and has less glycation overall, making HbA1c falsely low.

Hyperglycemia would raise HbA1c, not lower it, so that option wouldn’t fit. Iron deficiency anaemia tends to slow red cell turnover and can falsely elevate HbA1c, while CKD can affect HbA1c accuracy through factors like anemia and transfusions but doesn’t classically cause a false low in the same way as haemolysis. If HbA1c seems discordant with glucose readings, consider alternative measures such as fructosamine or glycated albumin, or use continuous glucose monitoring.