Effect of diabetes on the cutaneous microcirculation of the feet in patients with intermittent claudication

Aims: To evaluate endothelial-dependent and -independent cutaneous vasodilator responses in the feet of patients with peripheral arterial disease (PAD) with or without Type 2 diabetes.

Methods: Cutaneous microvascular responses in the dorsum of both lower limbs were measured in the supine position using Laser Doppler Fluximetry combined with iontophoretic administration of endothelial-dependent (acetylcholine, Ach) and -independent (sodium nitroprusside, SNP) vasodilators in diabetic (n = 19) and non diabetic (n = 17) patients with PAD (presenting as unilateral calf intermittent claudication (IC).

Results: In patients with diabetes and IC, endothelial-dependent vasodilation was significantly impaired in the symptomatic limb [74 (57,105) vs 68 (24,81) PU, Z = -2.79, p = 0.005] compared to the asymptomatic limb. Patients without diabetes showed no impairment of vasodilation. Resting ankle-brachial pressure index did not identify the presence of abnormalities in microvascular function.

Conclusions: The combination of diabetes and PAD is associated with a reduction in endothelial-dependent cutaneous vasodilation in the feet without an associated reduction in endothelial independent vasodilation.