Correlation of HbA1c with Serum Iron & Transferrin Saturation in Non-Diabetic Patients with Iron Deficiency

Objective: To determine correlation of HbA1c with serum iron and transferrin saturation in non-diabetic patients with iron deficiency.

Methods: This cross-sectional comparative study was conducted at Dr Ruth KM Pfau Civil Hospital Karachi from 15th September 2021 to 14th March 2022, on non-diabetic patients based on fasting blood sugar (FBS) of <100 mg/dl. Patients were divided into two groups. Group one included patients having iron deficiency anemia (ID), whereas group two included same number of age and sex matched healthy subjects taken as controls, without ID. Blood sample was taken for HbA1c, CBC, serum iron and total iron binding capacity. Transferrin saturation (TSAT) was calculated. Comparison of quantitative variables with ID and non-ID group was done by Student’s t-test. Correlation of HbA1c with iron &TSAT was done in both groups using Kendal tau-b test, as data was not normally distributed.

Results: Out of 230 patients, 83 (36.1%) were males while 147(63.9%) were females. Mean age of patients was 43.7±13.28 years. Mean HbA1c level was significantly high in ID group (5.89±0.43) as compared to non-ID group (5.52±0.50) with a p-value <.001. The HbA1c levels correlated negatively with hemoglobin, serum iron levels and transferrin saturation with a p-value <.001.

Conclusion: Low serum Iron and TSAT was related to elevation in HbA1c value. Iron deficiency needs to be corrected before HbA1c interpretation.