Influence of anemia on levels of glycosylated hemoglobin/HbA1C

Abstract

Background: Glycated hemoglobin (HbA1c) is the standard biomarker for assessing long-term glycemic control in patients with diabetes mellitus. However, several hematological conditions, particularly iron deficiency anemia (IDA), may influence HbA1c values independently of blood glucose levels, potentially leading to inaccurate assessment of glycemic status.

Methods: This case-control study included 60 participants comprising 30 diabetic patients with anemia (cases) and 30 diabetic patients without anemia (controls). HbA1c was measured by high-performance liquid chromatography (HPLC), plasma glucose, hemoglobin concentration, and other hematological parameters were assessed. Statistical analyses were performed to compare the two groups. Following ethical guidelines, informed consent was obtained from all participants.

Results: HbA1c levels were significantly higher in diabetic patients with anemia compared with non-anemic diabetic patients, despite comparable plasma glucose levels. These findings suggest that iron deficiency anemia may falsely elevate HbA1c values, likely due to prolonged red blood cell survival, allowing greater glycation of hemoglobin.

Conclusions: Iron deficiency anemia significantly affects HbA1c levels in diabetic patients and may lead to misinterpretation of glycemic control if HbA1c is used to monitor. Routine screening and appropriate management of anemia should be done to improve the accuracy of HbA1c interpretation. In patients with anemia, alternatives of glycemic control, such as fructosamine or continuous glucose monitoring (CGM), should be considered. Further research is warranted to evaluate the effects of anemia and to assess changes in HbA1c following anemia correction, thereby enhancing diabetes monitoring.