ENDOTHELIAL DYSFUNCTION OF CONDUIT ARTERIES INSULIN-DEPENDENT DIABETES-MELLITUS WITHOUT MICROALBUMINURIA

Objective: Previous studies have shown that endothelial dysfunction, a n early sign of atherosclerosis, occurs in animal models of diabetes m ellitus and in resistance vessels of patients with insulin-dependent d iabetes. In the present study we examined whether young patients with insulin-dependent diabetes without microalbuminuria present abnormal e ndothelial function of large peripheral arteries. Methods: Twenty-six patients with insulin-dependent diabetes without microalbuminuria were compared with 26 normal controls and 5 patients with insulin-dependen t diabetes with microalbuminuria. Brachial artery diameter was measure d at rest, during reactive hyperaemic flow (endothelium-dependent dila tation) and after sublingual isosorbide dinitrate (endothelium-indepen dent dilatation). Results: Baseline artery diameter and flow as well a s the degree of reactive hyperaemia were similar in all groups compare d to controls. Flow-mediated dilatation was lower in patients with dia betes without microalbuminuria (5.8 +/- 7 vs 11 +/- 7%, P = 0.01) as w ell as in patients with diabetes without microalbuminuria (0.75 +/- 2. 5 vs 11 +/- 7%, P = 0.003), nitrate-induced dilatation was normal in p atients without microalbuminuria and attenuated in patients with micro albuminuria. In the group of diabetes patients without microalbuminuri a, those with disease duration > 10 years and HbAl(c) > 6% had the wor se endothelial function. Conclusions: Our results demonstrate that end othelial dysfunction of conduit arteries can be detected in patients w ith insulin-dependent diabetes mellitus without microalbuminuria, prob ably contributing to the high prevalence of atherosclerosis in these p atients.