Iron Deficiency Anemia Effects on Glycemic Control

Iron deficiency anaemia alters the composition and turnover of circulating erythrocytes, leading to distortions in glycated haemoglobin (HbA1c) measurements independent of true glycaemic status. Reduced haemoglobin content and prolonged red cell survival increase the opportunity for non‐enzymatic glycation, often yielding spuriously elevated HbA1c values. Such artefacts may result in misclassification of prediabetes or diabetes, with implications for clinical decision-making, therapeutic targets and public health surveillance. Conversely, iron repletion reverses these effects, lowering HbA1c without necessarily reflecting changes in ambient glucose. Beyond HbA1c, alternative metrics—such as fasting plasma glucose and continuous glucose monitoring—may offer more reliable assessment in iron‐deficient populations. Given the global prevalence of iron deficiency anaemia, particularly in low-resource settings and among women of reproductive age, awareness of these interactions is essential to avoid misdiagnosis, inappropriate intensification of therapy and undue patient anxiety. Integration of iron status screening into routine diabetes assessment, and adjustment of interpretative frameworks for HbA1c in anaemic individuals, can improve accuracy and equity in glycaemic monitoring.

Research from Nature Portfolio

Recent studies have shown that common alterations in red blood cell indices do not universally impair the diagnostic accuracy of HbA1c for dysglycaemia. In a large cohort of reproductive-aged women, individuals with low haemoglobin or reduced mean corpuscular volume exhibited similar overall performance of HbA1c in detecting prediabetes and diabetes compared with those having normal indices. Ethnic subgroups displayed variation in assay performance, suggesting that local reference thresholds and population diversity must be considered when interpreting HbA1c in the presence of subclinical anaemia.

Iron Deficiency Anemia Effects on Glycemic Control publication trend

The graph below shows the total number of articles in iron deficiency anemia effects on glycemic control across all publications each year (not limited to Nature Index journals).

Technical terms

Glycated haemoglobin (HbA1c): A form of haemoglobin chemically bound to glucose, reflecting average blood glucose levels over the previous two to three months.

Mean corpuscular volume (MCV): The average volume of individual red blood cells, used to characterise types of anaemia.

Red cell distribution width (RDW): A measure of the variation in red blood cell size, indicating heterogeneity in cell populations.

Transferrin saturation (TSAT): The percentage of transferrin iron-binding sites occupied by iron, reflecting iron availability.

Dysglycaemia: Any abnormality in blood glucose regulation, including impaired fasting glucose, impaired glucose tolerance and diabetes.

References

1. Implications of iron deficiency/anemia on the classification of diabetes using HbA1c. Nutrition & Diabetes (2015).
2. The effect of different types of anemia on HbA1c levels in non-diabetics. BMC Endocrine Disorders (2023).
3. Influence of red blood cell indices on HbA1c performance in detecting dysglycaemia in a Singapore preconception cohort study. Scientific Reports (2021).
4. The Effect of Iron Replacement Therapy on HbA1c Levels in Diabetic and Nondiabetic Patients: A Systematic Review and Meta-Analysis. Journal of Clinical Medicine (2023).