Effects of arm-cranking exercise in cutaneous microcirculation in older, sedentary people

Microvascular integrity is compromised by several diseases and conditions as well as age. Exercise can reverse these effects but it is unclear whether these are systemic or localised, or which mechanisms are responsible for observed improvements Therefore, the primary objective of this study was to assess whether arm-cranking exercise had a systemic or localised cutaneous, microcirculatory effect in an older, healthy population and compare these findings with our previous work on patients with chronic venous disease. A secondary objective was to see if improvements were greater in the lower- or in the upper-limb.

Endothelial-dependent- and independent-vasodilation were assessed on the forearm and the perimalleolar region in 14 older (59±4.5years), sedentary, healthy participants using LDF and incremental doses of acetylcholine (ACh) and sodium nitroprusside (SNP), before and after a session of arm-cranking exercise. Cutaneous blood flux data were expressed as cutaneous vascular conductance (CVC).

Endothelial-dependent vasodilation increased both in the upper- (p=0.04, d=0.59) and lower-limb (p=0.03, d=0.52), after exercise. Endothelial-independent vasodilation did not change either in the lower- and upper-limb (p>0.05 on both occasions). "Between-limbs" comparison showed that pre-exercise differences between the forearm and the lower-leg (p=0.04, d=0.47) disappeared after ACh-induced vasodilation, following arm-cranking exercise (p>0.05). Conversely, SNP-induced did not change.

Our results suggest that in a healthy, sedentary population (and in contrast to post-surgical varicose vein patients), acute arm-cranking exercise leads to an improvement of microvascular endothelial function in the extremities.