No decreased erythrocyte deformability in type 1 (insulin-dependent) diabetes, either by filtration or by ektacytometry.

A lower erythrocyte deformability, which causes impairment of the microcirculation, is postulated to contribute to diabetic organ complications. Erythrocyte deformability was measured in four groups of type 1 (insulin-dependent) diabetic subjects and 30 controls by filtration and ektacytometry. Twenty-five patients without organ complications, 21 with microalbuminuria, 13 with overt nephropathy and 12 with leg ulceration were studied. No decreased erythrocyte deformability was found in any of the diabetic groups with either technique, and neither did the total group of 71 diabetic subjects have a lower erythrocyte deformability when compared with the controls. In order to imitate local conditions in the kidney, erythrocyte deformability was also measured in hyperosmolar solutions. Again no differences were found between the diabetic groups separately or as a whole and the controls. Furthermore no correlation was found between erythrocyte deformability and the plasma glucose or glycosylated haemoglobin level.

Blood and plasma viscosity in diabetes: possible contribution to late organ complications?

It has been postulated that an increased whole blood and plasma viscosity contribute to diabetic organ complications. Blood viscosity was measured in 30 controls and four groups of insulin-dependent diabetic patients at three shear rates: 70 sec-1, 0.5 sec-1 and 0.05 sec-1. Results were compared before and after correction for a haematocrit of 0.45. Twenty-five patients without organ complications, 21 with microalbuminuria, 13 with overt nephropathy and 12 patients with leg ulcerations were studied. Blood and plasma viscosity were normal in the patients without organ complications and with microalbuminuria. Plasma viscosity was significantly elevated in the diabetic patient with nephropathy and leg ulceration. After correction for haematocrit blood viscosity was also higher in these two groups, although this was only significant in the group with leg ulceration. In conclusion blood and plasma viscosity were only elevated in the patients with major organ complications and not in the patients without or with early complications. Therefore it is unlikely that an elevation of blood or plasma viscosity contributes early in the pathogenesis of diabetic organ damage.