A patient with hemolytic anemia will:

• A. show a decrease in glycated Hgb value
• B. show a increase in glycated Hgb value
• C. show little or no change in glycated Hgb value
• D. demonstrate an elevated Hgb A1

Answer: (A)

Glycated hemoglobin (HbA1c) reflects the average blood glucose over the lifespan of circulating red blood cells. In hemolytic anemia, red cells are destroyed more quickly than normal, so their average lifespan is shortened. Because HbA1c forms gradually as glucose remains in contact with hemoglobin, a shorter red cell lifespan means less time for glycation to occur. The result is a falsely lower HbA1c value than what the actual average glucose would suggest.

So the best answer is a decrease in glycated Hgb value. An increased HbA1c would require longer red cell exposure to glucose, which isn’t the situation here. Little or no change would ignore the effect of accelerated turnover, and stating elevated HgbA1 doesn’t address the glycated fraction being measured.