Effects of atherosclerosis on the cutaneous regional and microcirculatory response to ischemia.

The cutaneous vascular response to gravity load is abnormal in atherosclerosis. In this study we compared the macrocirculatory and microcirculatory response to ischemia in atherosclerotic smokers, nonatherosclerotic smokers, and healthy nonsmokers. Using videodensitometry, the capillary blood velocity of hallux nail fold capillaries was measured at rest and following 1 minute of ankle cuff occlusion. Blood-flow velocity of the dorsal metatarsal artery was measured by ultrasound Doppler. Resting dorsal metatarsal artery velocity and capillary blood velocity of atherosclerotic subjects were lower than those of nonatherosclerotic smokers and nonsmokers. The dorsal metatarsal artery velocity and capillary blood velocity increased in each group following occlusion. Peak postocclusion dorsal metatarsal artery velocity was lower in the atherosclerotic subjects, but peak capillary blood velocity was not significantly different among groups. Atherosclerosis does not alter the mechanisms of reactive hyperemia in either the macrocirculation or the microcirculation. The magnitude of hyperemia is diminished at the macrocirculatory level.