Critical Relationship Between Iron Deficiency Anaemia (IDA) and Glycated Haemoglobin (HbA1c): An Updated Review

This review explores the complex relationship between Iron Deficiency Anaemia (IDA) and glycated haemoglobin (HbA1c) levels, a critical marker for diabetes mellitus. The objective is to evaluate how IDA influences HbA1c measurements and its implications for diabetes diagnosis and management, particularly in populations with high IDA prevalence.

A narrative mini-review was conducted, synthesizing evidence from studies identified through PubMed, MEDLINE, and Google Scholar. The search focused on English-language articles published between 1982 and 2024, adhering to PRISMA guidelines. Studies were selected based on their relevance to IDA and HbA1c, with 57 articles meeting the inclusion criteria after rigorous screening.

The review revealed conflicting findings: some studies reported elevated HbA1c levels in IDA patients independent of glycemic status, potentially leading to diabetes overdiagnosis, while others found no significant association. Proposed mechanisms included altered erythrocyte turnover, structural haemoglobin modifications, and oxidative stress-induced glycation. Iron replacement therapy was shown to normalize HbA1c levels in many cases, underscoring the importance of addressing iron status in diabetic patients with concomitant anaemia.

The findings highlight the need for cautious interpretation of HbA1c results in IDA patients, especially in high-risk groups like premenopausal women. Alternative glycemic markers, such as glycated albumin or fructosamine, may be valuable in such scenarios. Methodological variations in HbA1c measurement and population differences were identified as key confounding factors.

The study underscores the intricate interplay between IDA and HbA1c, emphasizing the necessity of considering iron status in diabetes diagnosis and management. Future research should focus on standardizing assessment protocols and elucidating the molecular pathways linking iron metabolism to haemoglobin glycation. These insights are crucial for improving diagnostic accuracy and therapeutic outcomes in affected populations.