Vascular reactivity and platelet aggregability during the first five years of insulin‐dependent diabetes in children

Skin microvascular reactivity and platelet aggregation in response to collagen and adenosine diphosphate (ADP) was studied prospectively in a population-based cohort of children with newly acquired type 1 diabetes mellitus (IDDM), who have now been followed up longitudinally for 5 years. The skin microvascular vasodilation in response to ischaemia was recorded by means of transcutaneous oximetry at 37 degrees C and compared with that in a control group of 58 healthy children. Platelet aggregation was compared with 42 healthy control children. Sixty months after diagnosis, the same degree of impairment of vasodilatory capacity was noted as previously recorded at 24 months and on admission, on all these occasions being significantly lower than the control value and the results from the 12-month follow-up. A sex difference was noted, diabetic girls both during and after puberty exhibiting a greater impairment of vasodilator capacity as compared with diabetic boys. The same degree of platelet aggregation in response to collagen was noted 60 months after diagnosis as had been recorded previously at 24 and 12 months, all significantly increased as compared with the results from admission, but not different from those in controls. By contrast, the aggregation in response to ADP was now lower than that observed on admission. No statistically significant gender difference was noted. The implication of the impaired skin microvascular vasodilation and of the changing pattern of platelet aggregation for later diabetic angiopathy needs to be evaluated in the coming decade.