Comparison of Hematological Parameters in Patients with Type 2 Diabetes, Obese Individuals, and Healthy Controls: A Comparative Cross-Sectional Study in Kerman City

Background: Given the increasing global prevalence of diabetes and obesity and their extensive complications, understanding hematological alterations in these conditions is of particular importance. This study aimed to investigate the association between glycemic control and obesity with hematological parameters. Methods: This comparative cross-sectional study included 1037 individuals: 100 patients with type 2 diabetes, 217 obese individuals (BMI ≥ 30 kg/m²), and 720 healthy individuals (BMI < 25 kg/m²), selected in Kerman, Iran, during 2019–2020. Fasting blood samples (12–14 hours) were obtained to measure laboratory parameters including fasting blood glucose, hemoglobin A1C, complete lipid profile, and hematological indices (complete blood count). Results: Hemoglobin and hematocrit levels were significantly lower in the diabetic group than in controls (13.27 ± 0.14 vs. 13.73 ± 0.05 g/dL, p= 0.004; and 40.69 ± 0.42% vs. 42.19 ± 0.15%, p< 0.001, respectively; mean ± SEM). Platelet count was significantly higher in the obese group than in controls (250.63 ± 3.80 vs. 239.81 ± 2.24 × 10³/μL, p= 0.019). RDW was significantly higher in the obese group than in controls (14.29 ± 0.10% vs. 13.92 ± 0.04%, p< 0.001). Fasting blood glucose showed significant negative correlations with red blood cell count (r= −0.330), hemoglobin (r= −0.445), and hematocrit (r= −0.417) (all p< 0.001). Conclusion: Both diabetes and obesity are associated with significant alterations in hematological parameters. Reduced hemoglobin and hematocrit in diabetes may reflect early metabolic or renal changes, whereas elevated platelet count and RDW in obesity may indicate a chronic inflammatory state.