Vascular reactivity in diabetes mellitus.

Cardiovascular disease is responsible for 70% of the deaths in diabetes mellitus. Endothelial dysfunction occurs early in atherosclerosis and can now be assessed accurately and reproducibly by noninvasive means. Hyperglycemia, insulin resistance, microvascular complications, and coexistent conditions have been shown to impair endothelial function in diabetes. Resistance to insulin's vasodilatory effect and increased free radical generation are probable mechanisms responsible for the endothelial dysfunction in this state. Improvement in glycemic control, insulin and insulin sensitizers, cholesterol lowering, hypolipidemic agents, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers have improved clinical cardiovascular outcomes and have also been shown to improve endothelial function. Strategies designed to assess and improve endothelial function may be further beneficial in terms of cardiovascular outcomes in diabetes mellitus, and need to be tested in a clinical setting.