HEMORHEOLOGY IN INSULIN-DEPENDENT DIABETES IS STILL NORMAL 5 YEARS AFTER ONSET OF THE DISEASE

In the development of insulin-dependent diabetes mellitus (IDDM), rheo logical changes have been shown to precede clinically detectable micro angiopathy. We studied 34 IDDM children 13.1 (6-20) years old with a d uration of the disease of 5 years and with a haemoglobin Al, of 8.3% ( 4.5-12.8%). Fifteen apparently healthy children 14.7 (10-18) years old served as a control group. Whole blood and plasma viscosity, erythroc yte aggregation tendency and erythrocyte fluidity were assessed by rot ational couette viscometry. Apart from a significantly higher haematoc rit (Hct) (42.6 vs 40.1; p < 0.05), the IDDM group did not differ from the controls in any of the measured in vitro theological variables. T he difference in Hct was due to an abnormally high Hct in the female d iabetic group. The subgroup of female diabetics also displayed a highe r plasma viscosity and fibrinogen concentration than the diabetic male s. Despite the sex differences in the diabetic group, blood rheology w as still normal in both sexes in this early stage of the IDDM disease. These findings suggest that altered haemorheology is a late phenomeno n (i.e. later than 5 years after the onset of the disease) in the deve lopment of vascular disease in IDDM.