Skin capillary circulation is more impaired in the toes of diabetic than non-diabetic patients with peripheral vascular disease.

The aim of the present study was to investigate if diabetes negatively influences the skin microvascular reactivity in the toes of patients with peripheral vascular disease (PVD). Twenty healthy subjects, 20 diabetic, and 20 non-diabetic patients with PVD participated. One foot in each subject was investigated. The patient groups were matched for age, sex, and toe pressure. The capillary blood cell velocity in the nailfold of the great toe was investigated by videophotometric capillaroscopy, and the total skin microcirculation within the same area by laser Doppler fluxmetry. Capillary blood cell velocity and laser Doppler flux were studied during rest, and following a 1 min arterial occlusion at the toe base. The skin microvascular reactivity was impaired in both diabetic and non-diabetic patients. In the diabetic patients the disturbances were mainly seen in the capillaries, and the capillary blood flow was severely reduced during reactive hyperaemia (p < 0.01). In contrast, the total skin microcirculation was normal, indicating that sufficient blood reaches the area, but does not come out into the capillaries. The ratio between capillary blood cell velocity and laser Doppler flux, representing the distribution of blood between nutritional and non-nutritional blood compartments, was reduced in the diabetic patients (p < 0.05). These findings may contribute to the higher risk for development of chronic foot ulcers in diabetic patients with PVD.