Glycated Hemoglobin, also known as HbA1c or A1c, is a very useful test that tells your average blood glucose values roughly over prior three months. It does this by measuring how much of your blood hemoglobin is glycated or has an added glucose molecule. Since your red blood cells are recycled every three months, their glycated hemoglobin also gets out of the blood circulation. Read more on this website: Glycated Hemoglobin: A Test to Measure Long Term Blood Glucose Control.
A blood transfusion or blood loss can change the red blood cell composition, altering the measured value of HbA1c. Similarly, various medical problems that lead to anemic conditions can show elevated HbA1c results compared to the actual values.
In developing countries, iron deficiency anemia is very common and the HbA1c values in such population will tend to be higher. If one has uncontrolled hypothyroidism, anemic conditions prevail leading to a similar problem.
In the late stages of pregnancy, there could be a shortfall of iron in the blood causing anemia. In such cases, HbA1c levels measured will be higher than the actual ones. Since there is a medical condition called Gestational Diabetes, in which the pregnant woman develops diabetes, one must be careful in interpreting HbA1c values which could be correctly higher due the diabetes versus incorrectly higher due to anemic conditions.
Finally, all the incorrect measurements will revert to accurate values once the deficiencies are corrected using medicines or supplementation. My short video on this subject below.
To read more
- On diabetes.co.uk: Scientists question accuracy of HbA1c testing due to red blood cell age variability (simple)
- Article: Could Your Hemoglobin A1C Test Be Wrong? (simple)
- Article: Factors that Interfere with HbA1c Test Results (for medical practitioners)
- Research paper: Pitfalls in Hemoglobin A1c Measurement (technical)
First published on: 3rd December 2021
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