Association Between Red Cell Distribution Width (Rdw) And HbA1c In Non-Anemic Patients With Type 2 Diabetes Mellitus

Aim: Diabetes mellitus (DM) is a complex disease characterized by chronic hyperglycemia that leads to complications affecting the kidneys, eyes, peripheral nerves, and micro- and macrovascular systems. Monitoring glycemic control is crucial for the prevention of these complications. Hemoglobin A1c (HbA1c) has long been used as the gold standard indicator of glycemic control. In recent years, red cell distribution width (RDW), one of the hematological parameters, has been associated with cardiovascular diseases, chronic kidney disease, and diabetes-related complications.The aim of this study was to evaluate the relationship between red cell distribution width (RDW) and HbA1c, as well as micro- and macrovascular complications, in patients with type 2 diabetes mellitus. In addition, the potential utility of RDW as a marker of microvascular complication risk was investigated.Materials and Methods: This retrospective study included 310 patients with type 2 diabetes mellitus and 328 healthy controls. Medical records of non-anemic patients were reviewed. Data regarding RDW, hemoglobin, creatinine, and microvascular complications (retinopathy assessed by ophthalmologic examination, nephropathy assessed by 24-hour or spot urine analysis, and neuropathy assessed by electromyography) were collected.Results: RDW levels were significantly higher in the diabetic group (13.92 ± 1.22) compared with the control group (12.77 ± 1.54) (p < 0.001). A significant positive correlation was observed between RDW levels and microalbuminuria in 24-hour urine samples (r = 0.291, p < 0.001). An RDW cut-off value of 13.47% predicted nephropathy with 73% sensitivity and 61% specificity (AUC = 0.689, p < 0.001).Conclusion: RDW was found to be associated with HbA1c in patients with type 2 diabetes mellitus. Among microvascular complications, only diabetic nephropathy was significantly associated with RDW levels.