Effect of metabolic control and concomitant diseases upon the rheology of blood in different states of diabetic retinopathy.

The flow properties of blood are abnormal in diabetes. The red cell deformability (RCD) is reduced and depends on the metabolic state; the red cell aggregation (RCA) and plasma viscosity are increased independent of the metabolism. According to the following nosological factors 157 diabetics were studied: duration of diabetes, type of therapy, ophthalmoscopic status, metabolic state and general health status. Although a deterioration of the flow properties of blood can be observed in long-term diabetics, in patients receiving antidiabetic drugs or insulin and in cases of pronounced retinopathy, these changes can all be attributed to a higher incidence of insufficiently controlled metabolism and to the presence of subsequent diseases. There is some evidence that the rheological changes cannot be neglected considering the development and progression of diabetic microangiopathy.