Correction of blood hyperviscosity in diabetics with microangiopathy by haematocrit reduction (therapeutic implications)

Abstract

Haematocrit, whole blood viscosity and blood viscosity at constant haematocrit of 45% were investigated in 271 diabetics with retinopathy and 20 healthy subjects. In whole blood, hyperviscosity was detected in 16% of the diabetic patients. In blood at haematocrit of 45%, hyperviscosity was found in 40.2% of the patients. When the viscosity measurements were performed at constant haematocrit, the parameter which had most influence on viscosity was red cell rigidity. Many of the diabetics with enhanced red cell rigidity achieved normalization of blood flow by haematocrit reduction. This observation suggests the existence of viscoreceptors. as suggested by Dintenfass, that detect red cell rigidity and develop compensating mechanisms.