ABSTRACT
Endothelial dysfunction is an important pathogenetic factor in both micro- and macrovascular complications of diabetes mellitus [DM]. The significance of microalbuminuria [MAU] and diabetic retinopathy [DR] as early indicators of endothelial dysfunction in the disease remains controversial. We studied 40 patients with type 2 diabetes and microalbuminuria and 20 age and sex matched control subjects. They were subjected to detailed clinical examination, fundus examination and laboratory investigations including measurement of fasting blood glucose, serum lipid profile, blood urea, serum creatinine, plasma endothelin-l [ET-1] and 24 hours urinary albumin excretion [UAE], besides ultrasonographic assessment of post- obstructive flow-mediated endothelium- dependent increase in brachial artery diameter and blood flow and measurement of carotid artery intima- media thickness [IMT]. Features suggestive of endothelial dysfunction [DR, increased ET-1 and impaired vascular reactivity] were prevalent in the diabetic patients. They had, as well, a statistically significant increase in carotid IMT compared to controls [P = 0.000]. Endothelium- dependent dilatation [EDD] of the brachial artery showed statistically significant negative correlations with urinary albumin excretion [UAE] rate, plasma ET-1 and carotid IMT. We conclude that endothelial dysfunction is common in diabetic patients with MAU. ET-1 is a sensitive marker of endothelial activation/dysfunction but it is affected by many variables. Ultrasonographic studies of superficial arteries, if properly performed, can help in delineating both early functional and pathological alterations of atherosclerosis