Effect of Iron Deficiency Anemia on HbA1c Levels in a cohort of patients with Type 2 diabetes mellitus in a tertiary care hospital

Abstract

Introduction: Studies have reported that HbA1c levels can be changed by iron deficiency (ID) which is the commonest nutritional anaemia globally. This study was aimed at determining the effect of iron deficiency anaemia (IDA) on HbA1c levels in a cohort of type 2 diabetes mellitus (T2DM) attending a tertiary care hospital in Sri Lanka. Methods: A retrospective analytical study was performed for a period of six months from January 2021. Laboratory records of 281 adult T2DM patients both, anaemic (n=135) with Hb <12g/dL in females and <13g/dL males and transferrin saturation <16%, and nonanaemic (n=146) with Hb >12g/dL in females and >13g/dL in males were analyzed. Data were analyzed using (SPSS) version 20, descriptive statistical methods, Pearson’s Correlation test, independent sample t-test, one-way analysis of variance (ANOVA) and Chi-Square test were used. P<0.05 was considered significant. Results: Out of the total 281 patients diagnosed with T2DM, 150 were female, and 131 were male, spanning an age range of 22 to 96 years. The mean ± standard deviation (SD) values for HbA1c in both anaemic and non-anemic groups were 7.4±2.2% g/dL and 7.3±2.36% g/dL, respectively. Importantly, no statistically significant relationship was observed between the two groups (p=0.889). Furthermore, there was no significant correlation between HbA1c levels with serum iron (p=0.617), total Iron Binding Capacity (TIBC) (p=0.340), and transferrin saturation (p=0.168). Conclusion: The study reveals, HbA1c in T2DM patients with and without IDA show no significant difference. Therefore, HbA1c could be reliably used in monitoring patients with T2DM and IDA.

Keywords: T2DM, HbA1c, iron deficiency anaemia, red blood cell indices