Impaired Leg Vasodilatory Function After Stroke

Abstract

Background and Purpose— Resting and reactive hyperemic leg blood flows are significantly reduced in the paretic compared with the nonparetic limb after disabling stroke. Our objective was to compare the effects of regular treadmill exercise (TM) with an active control regimen of supervised stretching (CONTROL) on peripheral hemodynamic function. Methods— This intervention study used a randomized, controlled design, in which participants were randomized with stratification according to age and baseline walking capacity to ensure approximate balance between the 2 groups. Fifty-three chronic, ischemic stroke participants (29 TM and 24 CONTROL) with mild to moderate hemiparetic gait completed bilateral measurements of lower leg resting and reactive hyperemic blood flow using venous occlusion strain gauge plethysmography before and after the 6-month intervention period. Participants also underwent testing to track changes in peak aerobic fitness across time. Results— Resting and reactive hyperemic blood flows were significantly reduced in the paretic compared with the nonparetic limb at baseline before any intervention (−28% and −34%, respectively, P <0.01). TM increased both resting and reactive hyperemic blood flow in the paretic limb by 25% compared with decreases in CONTROL ( P <0.001, between groups). Similarly, nonparetic leg blood flow was significantly improved with TM compared with controls ( P <0.001). Peak aerobic fitness improved by 18% in TM and decreased by 4% in CONTROL ( P <0.01, between groups), and there was a significant relationship between blood flow change and peak fitness change for the group as a whole ( r =.30, P <0.05). Conclusion— Peripheral hemodynamic function improves with regular aerobic exercise training after disabling stroke.