Acute effect of exercise-induced leg ischemia on cutaneous vasoreactivity in patients with stage II peripheral artery disease.

Abstract

Conflicting data are available regarding the acute effect of exercise-provoked leg ischemia on the endothelial function in patients with stage II peripheral artery disease (PAD). In order to clarify this issue, cutaneous hyperemic responses to iontophoresis delivery of an endothelium-dependent (acetylcholine, ACh) and an endothelium-independent (sodium nitroprusside, SNP) vasodilator were evaluated under resting conditions, and before and after a treadmill test, using laser Doppler flowmetry, in 14 males (aged 68 +/- 4 years) affected by stage II PAD; 14 age-matched healthy males served as controls. At resting, a significantly reduced skin hyperemic response to ACh and to SNP was observed in PAD patients when compared to controls. Following treadmill, the leg skin hyperemic response to ACh delivery was significantly lower at peak of claudication than prior exercise (139 +/- 10 vs 213 +/- 25%, P = 0.01) in PAD patients, whereas no difference was observed in controls. The hyperemic response to SNP after exercise did not differ from baseline in either PAD patients or controls. The present data are in keeping with a reduced skin vasodilator capacity in stage II PAD patients at resting. In addition, the further impairment of skin endothelium-dependent vasodilation at the peak of claudication could indicate an acute endothelial dysfunction associated with exercise-induced leg muscle ischemia. These preliminary results also suggest that the threshold of claudication should not be exceeded during rehabilitation programs for PAD patients.