The Significance of Erythrocyte Rigidity in the Development of Microangiopathy in Patients with Type 2 Diabetes Mellitus.

Introduction Rheological parameters (from the Greek "rheos" – flow) are properties of blood related to its flowability. In large vessels, inertial forces related to mass contribute most significantly to blood flow. However, in the microvascular system, the movement of blood flow is primarily influenced by its rheological properties. This is due to the higher resistance to blood flow in this area, which is determined by the architecture of the vascular system. The rheological properties of blood largely depend on blood viscosity – an integral parameter that defines blood flow. Key factors affecting the viscosity of whole blood include the volumetric concentration of formed elements in plasma, plasma properties, and cellular components' aggregation and deformability. Since the number of erythrocytes in the bloodstream far exceeds that of other formed elements (accounting for 93–98% of the total), the rheological properties, including blood viscosity, are predominantly determined by the volumetric concentration of erythrocytes. Thus, blood viscosity depends on the hematocrit level, plasma viscosity, and the ability of erythrocytes to aggregate and deform.