Age effect on vascular reactivity in Type 1 diabetes.

Aim The objective of this study was to assess the effect of age on vascular reactivity in patients with Type 1 diabetes. Methods Forty-five patients with Type 1 diabetes and 71 healthy control subjects, divided into three age groups (18-30, 31-45 and 46-60 years old), underwent assessment of vascular reactivity based on ultrasound examination of a brachial artery after nitric oxide donor administration. Results The vasodilative and haemodynamic effect was most pronounced in the youngest control subjects, where lumen widening of 0.51 ± 0.16 mm (13.9 ± 4.2%) and increase in early velocity of 28.4 ± 6.5 cm/ s (237 ± 55%) were observed, while, in the control subjects from the middle and oldest age groups, the increase in artery diameter was 0.4 ± 0.11 and 0.22 ± 0.12 mm (9.8 ± 2.6 and 5.0 ± 2.6%), respectively. In the youngest patients with diabetes, lumen widening by 0.35 ± 0.13 mm(8.6 ± 3.4%) and increase in early diastolic velocity by 16.9 ± 5.6 cm/ s (158 ± 52%)were noted (P < 0.05 vs. control subjects). In patients with diabetes from the middle and oldest age groups, the increase in artery diameter was 0.26 ± 0.06 and 0.16 ± 0.09 mm (5.5 ± 1.4 and 3.2 ± 1.8%), respectively. Conclusions Vascular reactivity is strongly age dependent in all subjects; however, responses are delayed and occur over a longer time period in the patients with diabetes. Vasodilation test protocols should take into account the age of the subjects. [ABSTRACT FROM AUTHOR]