The use of high frequency ultrasound to evaluate the effect of treadmill exercise on endothelial function with and without antioxidant vitamins

Brachial artery ultrasound has been employed to evaluate vasomotor responses as an index of endothelial function. Acute exercise appears to be an oxidative stress that affects endothelial function. Using high frequency 7.5mHz ultrasound, we evaluated flow-mediated brachial artery vasoactivity as an index of endothelial function in response to exercise with and without high dose antioxidant vitamins C and E in 19 normal subjects (aged 44 ± 15years). Brachial artery vasoactivity was expressed as percent diameter change from baseline to hyperemic stimulus (1 minute post 5 minute blood pressure cuff arterial occlusion). Flow-mediated vasoactivity decreased from 18 ± 11% to 8 ± 6% (p<0.01) immediately following treadmill exercise (3.4mph at 6% elevation for 30 minutes) without vitamins but did not significantly decrease (15% ± 7 to 14%± 6) when pretreated with vitamin C (1 gram) and E (800 IU). Conclusions: These data suggest that ultrasound can detect endothelial dysfunction in response to acute exercise and antioxidant vitamins can blunt this detrimental effect.