Implications of Iron Deficiency Anaemia on Glycemic Dynamics in Diabetes Mellitus: A Critical Risk Factor in Cardiovascular Disease.

Background: Iron deficiency anemia (IDA) is a highly prevalent comorbidity in patients with diabetes, with rates estimated between 13% and 47% across studies. Iron deficiency anemia may potentially influence hemoglobin A1c (HbA1c) values, which are routinely measured to monitor long-term glycemic control in diabetes. Some evidence suggests that HbA1c may be lower in diabetics with IDA due to increased red blood cell turnover. However, current evidence elucidating the effects of IDA on HbA1c and diabetes outcomes remains inconsistent and inconclusive.

Objective: This cross-sectional study aimed to evaluate the relationship between IDA, HbA1c levels, and glycemic dynamics in patients with diabetes mellitus.

Methods: The study sample included 143 adult patients diagnosed with diabetes, recruited from outpatient clinics in Saudi Arabia. Iron deficiency anemia was identified through serum ferritin <100 ng/mL, transferrin saturation <20%, and hematologic parameters. The HbA1c levels were measured using standardized laboratory methods. Daily glucose profiles were obtained by continuous glucose monitoring (CGM) in a subset of patients to assess glycemic dynamics.

Results: The prevalence of IDA was 39.9% among the diabetic cohort. Patients with IDA had a numerically higher mean HbA1c of 7.2% compared to 6.8% in non-anemic diabetics, suggesting a potential effect of IDA on HbA1c. Those with IDA also spent more time in hyperglycemic ranges, along with greater glucose variability based on CGM data. Iron deficiency measures, including low ferritin and high red cell distribution width (RDW), showed weak positive correlations with HbA1c levels.

Conclusion: Iron deficiency anemia is highly prevalent among Saudi diabetic patients and is potentially associated with inaccurate HbA1c values and poor short-term glycemic control. However, larger controlled studies are warranted to conclusively investigate mechanisms linking IDA to alterations in HbA1c and glycemic dynamics. Optimized screening and treatment of IDA may lead to more accurate diabetes monitoring and improved outcomes.