The effects of cholesterol levels on hemorheological parameters in diabetic patients.

Red blood cell (RBC) deformability is an important hemorheological parameter to determine the passage of RBC through narrow capillaries and the reduction of blood viscosity under high shear rates. Although it has been substantial evidence that diabetes mellitus (DM) and hypercholesterolemia increase the risk of coronary heart disease, the mechanism is unclear. In this study the relationship between hemorheological parameters and plasma cholesterol in type 2 diabetic patients (n=55, mean age 43.4+/-9.2 years) was examined. Type 2 diabetic patients were classified as normocholesterolemic (n=25; cholesterol < or = 200 mg/dl) and hypercholesteroloemic (n=30; cholesterol > 200 mg/dl) subgroups. Hypercholesterolemic type 2 diabetic patients had the highest blood and plasma viscosity and the lowest RBC deformability. The results were significantly different from normocholesterolemic type 2 diabetic patients (p<0.001). Our data suggest that elevated plasma cholesterol may impair RBC deformability and increase in blood and plasma viscosity by an additional effect to hyperglycemia in type 2 diabetic patients.