Impaired Red Blood Cell Deformability in Patients with Coronary Artery Disease and Diabetes Mellitus

Patients with diabetes mellitus (DM) have an increased cardiovascular morbidity and mortality. There is increasing evidence that diabetes mellitus is associated with pathological hemorheological alterations, which might contribute to impaired coronary blood flow in coronary artery disease (CAD). We hypothesize that red blood cell (RBC) deformability is impaired in diabetic patients with CAD in comparison to nondiabetic patients with CAD. RBC deformability was measured in 21 patients with CAD and type 2 diabetes mellitus (CAD + DM) and 24 patients with CAD (CAD - DM). RBC deformability was measured by the Laser-assisted optical rotational cell analyzer by determining the elongation index (EI). RBC deformability was reduced in patients with CAD + DM in comparison to patients with CAD - DM (EI @ 1.12 Pa 0.236 +/- 0.008 vs. 0.260 +/- 0.005, p = 0.007). Inverse univariate correlations were found between the EI @ 1.12 Pa and plasma glucose concentration (r = -0.57; p < 0.001) and HbA(1c) (r = -0.45; p = 0.002). Multivariate linear regression analysis identified plasma glucose concentration as the independent predictor of RBC deformability (beta = -0.58; p = 0.007) thereby indicating that increased glucose concentrations determine RBC deformability in diabetic patients with CAD. In patients with CAD, diabetes mellitus leads to an impairment of RBC deformability which might contribute to increased morbidity of diabetic patients with CAD.