Interference of iron deficiency in glycated hemoglobin testing and its clinical implications: a systematic review and meta-analysis.
Biochem Med (Zagreb)Oct 4, 2026
Emanuele Maria Coimbra Souza, Caroline Pereira Domingueti
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In 30 seconds
This systematic review and meta-analysis evaluated the impact of iron deficiency anemia (IDA) and latent iron deficiency (LID) on glycated hemoglobin (HbA1c) concentrations. Among 43 studies on IDA, 33 reported falsely elevated HbA1c levels. The meta-analysis confirmed an increase in HbA1c by 0.66% in patients with IDA (P < 0.001) and a reduction of 0.50% following iron therapy (P = 0.02).
Key findings
- 33 out of 43 studies on IDA reported falsely elevated HbA1c concentrations.
- HbA1c increased by 0.66% in patients with IDA (P < 0.001).
- LID was associated with an increase in HbA1c by 0.66% (P = 0.05).
- Iron therapy led to a reduction in HbA1c by 0.50% (P = 0.02).
Why it matters
Understanding the effects of iron deficiency on HbA1c levels is crucial for accurate diabetes diagnosis and management. Clinicians should consider iron status when interpreting HbA1c results to avoid misdiagnosis and inappropriate treatment.