Correlation between rheological parameters and erythrocyte velocity in nailfold capillaries in patients with diabetes mellitus.

Increased rheological parameters and disturbances of capillary perfusion are often observed in both types of diabetes. It is assumed that these alterations might be involved in the development and progression of diabetic microangiopathy. It has been shown elsewhere, that erythrocyte rigidity, erythrocyte and platelet aggregation, plasma viscosity and leucocyte adhesion are increased. By methods of microcirculation capillary perfusion can be investigated and in vivo no significant alterations can be found at rest. During reactive hyperemia flow reduction diminishes capillary perfusion in various organs. In this presentation hemorheological parameters and erythrocyte velocity in nailfold capillaries are investigated in both types of diabetes under various conditions. Plasma viscosity and spontaneous platelet aggregation are often increased, especially in patients with diabetes type 2 and in diabetic foot lesions. Improvement of the metabolic situation by insulin application reduces the elevated parameters and improves capillary perfusion. Long-term type 1 diabetics tend to show increased rheological factors and reduced capillary perfusion. Although an association between some hemorheological parameters and capillary perfusion seems to exist, a strong correlation cannot be found.