Effect of Iron Deficiency Anaemia on Haemoglobin A1c Levels

Abstract

Background: Iron deficiency anaemia is the most common form of anaemia in India. Haemoglobin A1c (HbA1c) is used in diabetic patients as an index to reflect glucose levels of the previous 3 months. Like blood sugar levels, HbA1c levels are also affected by presence of variant haemoglobin, haemolytic anaemia, nutritional anaemias, uremia, pregnancy and acute blood loss. However, reports on the effects of iron deficiency anaemia on HbA1c levels are inconsistent. We conducted a study to analyze the effects of iron deficiency anaemia on HbA1c levels and to assess whether treatment of iron deficiency anaemia affects HbA1c levels. Methods: Fifty patients confirmed to have iron deficiency anaemia were enrolled in the study. HbA1c levels of them were measured both at baseline and after 3 months of treatment of iron deficiency. These values were also compared with those in the control population. Results: The mean baseline HbA1c level in anaemic patients (6.60) was significantly higher than that of controls (5.48). However, after 3 months of treatment, significant decline from 6.60 to 5.74 was found in HbA1c levels. Conclusions: Our study proved that Iron deficiency anaemia has a straight forward correlation with HbA1c levels and the relationship is inverse between them. This signifies that as the level of haemoglobin drops with increasing severity of iron deficiency in anaemic subjects, at the same time HbA1c levels increase correspondingly. Moreover, with correction of iron deficiency in the anaemic subjects, the HbA1c levels decline to near normal values. Other than blood glucose, many other factors effect calculated HbA1c value which should be kept in mind before doing a therapeutic treatment modification. Iron deficiency anaemia being extremely common in Indian settings should always be ruled out when high HbA1c levels are detected and should be corrected on priority to achieve true levels of HbA1c.