Iron-deficiency anemia, non-iron-deficiency anemia and HbA1c among adults in the US*

Caution should be used when diagnosing diabetes and prediabetes among people with high or low Hb when the HbA1c level is near 6.5% or 5.7%, respectively, as changes in erythrocyte turnover may alter the test result. However, the trend for HbA1c to increase with iron deficiency does not appear to require screening for iron deficiency in ascertaining the reliability of HbA1c in the diagnosis of diabetes and prediabetes in a given individual.