Effect of iron deficiency anemia on HbA1c in diabetic patients at Tikur Anbessa specialized teaching hospital, Addis Ababa Ethiopia

BACKGROUND: Hemoglobin A1C (HbA1c) is the predominant hemoglobin found in HbA1 fractions. A1c assay is the recommended assay for diagnosing diabetes and any condition that changes red cell turnover such as Iron deficiency Anemia (IDA), will lead to spurious A1C results. Therefore, the present study was aimed at determining the effect of IDA on HbA1c in diabetic patients attending Black Lion Specialized Teaching Hospital, Addis Ababa, Ethiopia. METHODS: A facility based comparative cross sectional study was conducted on 174 diabetic patients (87 with IDA and 87 without IDA) from April to July 2016. Socio demographic data and clinical conditions were collected using structured questionnaire. Venous blood was collected for performing Complete blood count (CBC) using Cell dyn 1800 hematology analyzer; Serum ferritin, performed by COBAS INTEGRA 400/800 Chemistry analyzer and HbA1c tests, performed by COBAS C 111 analyzer. Data was analyzed using SPSS version 21 software. Pearson’s correlation, chi-square, and independent t-tests were calculated. The data was presented as mean ± SD. A P-value of < 0.05 was taken as statistically significant. RESULTS: Mean hemoglobin (Hgb), hematocrit (HCT), Mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC) were lower in IDA group compared to non-IDA diabetic patients. HbA1c (%) level was significantly lower in IDA group (6.18 ± 1.57) compared with the non-IDA diabetic patients (7.74 ± 1.81) (p < 0.05). CONCLUSION: HbA1c is significantly lower in diabetic patients with IDA compared to the non-IDA diabetic patients. Therefore, the authors believe that monitoring these patients using only HbA1c could be misleading, hence physicians and health care providers should take this into account before making any therapeutic decision. Detailed examination including large number of participants employing advanced laboratory techniques is recommended. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12878-018-0132-1) contains supplementary material, which is available to authorized users.