[Erythrocyte and platelet parameters and degree of control of diabetes]

There are abnormalities of haemostasis and rheological properties in uncontrolled diabetics which could well be involved in the pathogenesis of diabetic microangiopathy and macroangiopathy. Erythrocyte deformability was reduced with a negative correlation with the degree of control (blood sugar and glycosylated hemoglobin). In uncontrolled insulin dependent diabetics (IDD), returning blood sugar to normal with a continuous infusion of insulin using an artificial pancreas, improved deformability in several hours; even if the raised blood sugar was maintained artificially, a perfusion of insulin and still had the same effect; the poor erythrocyte deformability in IDD seems therefore to be related more to the level of insulin than to hyperglycaemia. This finding was confirmed in vitro: normal erythrocytes incubated in plasma from uncontrolled IDD had a low deformability, the addition of insulin in physiological concentration prevented this; after incubation for 3 h at 37 degrees C in the absence of insulin, erythrocyte deformability was low whereas in the presence of insulin, normal deformability was maintained. Platelets from IDD showed increased aggregation when measured in whole blood. This phenomenon seems to be mediated by erythrocytes because normal platelets became hyperagregable in the presence of "diabetic" erythrocytes.