Systematic review and meta-analysis: influence of iron deficiency anemia on blood glycosylated hemoglobin in diabetic patients.

BACKGROUND: Diabetes is a common metabolic disease with an increasing incidence in middle-aged and elderly people in recent years. Chronic hyperglycemia is the basic feature of diabetes, which can cause long-term damage to eyes, kidneys, nerves, heart, and blood vessels, resulting in functional decline or even failure. Glycosylated hemoglobin (HbA1c) can be used as an indicator of an individual's blood sugar status over the past 3 months; however, it is slightly affected by ischemic anemia. METHODS: The data retrieval was performed in the databases of PubMed, Embase, and Ovid-Medline from their inception to April 2021, including keywords such as iron deficiency anemia (IDA), diabetes, HbA1c, immunoassay, and ion-exchange chromatography. After passing of sensitivity and heterogeneity analysis, Review Manager 5.3 was employed for meta-analysis. RESULTS: A total of 6 studies were included in this paper. The analysis results showed that IDA could be considered to have an impact on HbA1c outcomes in non-diabetic populations. In people with diabetes, IDA is not thought to have an impact on HbA1c outcomes. DISCUSSION: A total of 6 articles were included to discuss the effects of IDA on blood HbA1c in diabetic patients. The study found that when patients with diabetes were tested for blood sugar, the HbA1c did not accurately reflect their blood sugar control over the past 3 months.