Effect of a single bout of prior moderate exercise on cutaneous perfusion in type 2 diabetes

Deterioration of cutaneous microcirculatory status of Kawasaki disease

Kawasaki disease (KD) is associated with generalized vasculitis with a predilection for coronary artery leading to ectasia and aneurysm in some cases. The aim of this study was to noninvasively assess the cutaneous microcirculation and correlate it with the coronary artery diameter in these patients. Laser Doppler flowmetry and dynamic capillaroscopy were performed at the nailbeds to assess total cutaneous blood flow and microcirculation in children with KD, both in the afebrile phase (after the resolution of fever) and convalescent phases, in comparison to controls. The 100 subjects analyzed in this study included 64 patients with KD (33 in afebrile phase and 31 in convalescent phase) and 36 normal controls. In KD, the capillary morphology was abnormal when compared to controls, with a larger diameter of the arterial and venous limbs, a higher intercapillary distance and a decrease in the loop numbers. Significantly decreased capillary blood cell velocity was noted in afebrile phase but not in convalescent phase. In the afebrile phase, a decreased capillary blood cell velocity significantly correlated with an increased coronary artery diameter. In conclusion, KD patients, both in the afebrile and convalescent phases, exhibited morphologic alterations in the microcirculation when compared to the controls. The results indicate the potential role of dynamic capillaroscopy for the noninvasive survey of microcirculation abnormalities in patients with KD.

Exercise status affects skin perfusion via prostaglandin, nitric oxide, and EDHF pathways in diabetes

Participation in regular exercise training improves dorsal skin perfusion, while type 2 diabetes mellitus (T2 DM) often limits it via reductions in the action or release of vasodilatory compounds. This study was undertaken to investigate the relative contributions of prostaglandins (PG), nitric oxide (NO), and endothelial-derived hyperpolarizing factor (EDHF) in dorsal foot skin perfusion in individuals with and without T2 DM and a sedentary lifestyle. Participants included 24 individuals with T2 DM and 28 nondiabetic controls whose exercise status was determined via questionnaire. Their dorsal foot skin perfusion was measured at rest using laser Doppler assessment during localized heating to 44 degrees C with oral aspirin (ASA, 325 mg) treatment. In addition, they received an infusion via a subcutaneous microdialysis probe of either saline (left foot) or L-NAME, a NOS-inhibitor (right foot). Compared to normative data without ASA, heat-stimulated perfusion in regular exercisers (n=22) was significantly more suppressed by ASA and by ASA/L-NAME than in sedentary individuals (n=30). Chronic exercisers exhibit a greater reliance on PG and lesser involvement of EDHF with unchanged NO compared to sedentary individuals, who rely more on EDHF and less on PG release. One possible exception may be diabetic, sedentary individuals, who may rely somewhat more on NO than EDHF. These results suggest that regular exercise may exhibit the greatest effect on the normal functioning of these vasodilatory pathways, although diabetes and a sedentary state together may somewhat alter their relative importance.

Impaired microvascular endothelial function is restored by acute lower-limb exercise in post-surgical varicose vein patients

Evidence exists that cutaneous microvascular endothelial dysfunction persists in patients following varicose vein surgery. This study compared cutaneous microvascular function between post-surgical varicose vein patients and healthy controls and investigated whether any impairment of function can be attenuated by acute lower-limb exercise. Cutaneous flux responses of the gaiter area were measured in supine and standing positions before and after a 25-min walk using laser Doppler fluximetry and incremental-dose administration of acetylcholine (ACh) and sodium nitroprusside (SNP). The pre-exercise peak responses to ACh (standing) were lower in patients than controls (48+/-11 vs. 96+/-28 PU; P=0.032), whereas treadmill exercise abolished this difference (P=0.819). In contrast, the pre-exercise responses to SNP (standing) appeared higher in patients than controls (3 mC responses: 24+/-4 vs. 10+/-2 PU, respectively; P=0.023), with no effect of acute exercise (P>0.05). These findings suggest that acute treadmill exercise augments microvascular endothelial function in post-surgical varicose vein patients to levels observed in age-matched controls.