Impact of Iron Deficiency Anemia on the Measurement of HbA1c in Non-Diabetic Population

Background: Iron deficiency anemia (IDA) is a prevalent condition with significant implications for public health. The impact of IDA on glycated hemoglobin (HbA1c) levels in non-diabetic individuals remains underexplored.

Aims: This study aimed to investigate the effect of IDA on HbA1c levels by comparing the HbA1c levels of non-diabetic patients having IDA and age/sex matched healthy controls. The study also compared the mean HbA1c levels with the severity of anemia, and the correlation between HbA1c and hemoglobin levels.

Study Design: Case-control study.

Place and Duration of Study: The study was conducted in the Medicine Emergency, Outpatient Department, and Medicine wards of the University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi from September 2022 to February 2024.

Methodology: We included 100 participants aged 18 to 65 years which comprised 50 lab-confirmed IDA cases and 50 age/sex matched healthy controls, after excluding those with diabetes or on hematinics. Detailed clinical history, examination, and investigations were carried out. Diagnosis of IDA was based on specific hematological parameters and confirmed by using serum iron and ferritin levels. Anemia severity was categorized based on hemoglobin levels into mild, moderate, and severe groups. HbA1c levels were measured using the standard HPLC method. The data was analyzed using SPSS software. The continuous variables were presented as means and standard deviations and the strength of correlation between variables was determined by Spearman's correlation coefficient.

Results: The mean HbA1c level was higher in the case group at 5.07% (SD = 0.42) compared to the control group at 4.68% (SD = 0.49) with (P < .001). A trend of increasing mean HbA1c values with the increasing severity of anemia was observed with mild, moderate, and severe anemia having mean HbA1c of 4.92%, 5.15%, and 5.20% respectively. We found a significant negative correlation between HbA1c and hemoglobin (P < .001).

Conclusion: The effect of IDA should be considered while interpreting HbA1c values.