Comparison of Brachial Artery Vasoreactivity in Elite Power Athletes and Age-Matched Controls

UNLABELLED: Elite endurance athletes typically have larger arteries contributing to greater skeletal muscle blood flow, oxygen and nutrient delivery and improved physical performance. Few studies have examined structural and functional properties of arteries in power athletes. PURPOSE: To compare the size and vasoreactivity of the brachial artery of elite power athletes to age-matched controls. It was hypothesized brachial artery diameters of athletes would be larger, have less vasodilation in response to cuff occlusion, but more constriction after a cold pressor test than age-matched controls. METHODS: Eight elite power athletes (age = 23 ± 2 years) and ten controls (age = 22 ± 1 yrs) were studied. High-resolution ultrasonography was used to assess brachial artery diameters at rest and following 5 minutes of forearm occlusion (Brachial Artery Flow Mediated Dilation = BAFMD) and a cold pressor test (CPT). Basic fitness measures included a handgrip test and 3-minute step test. RESULTS: Brachial arteries of athletes were larger (Athletes 5.39 ± 1.51 vs. CONTROLS: 3.73 ± 0.71 mm, p<0.05), had greater vasodilatory (BAFMD%: Athletes: 8.21 ± 1.78 vs. CONTROLS: 5.69 ± 1.56%) and constrictor (CPT %: Athletes: -2.95 ± 1.07 vs. CONTROLS: -1.20 ± 0.48%) responses, compared to controls. Vascular operating range (VOR = Peak dilation+Peak Constriction) was also greater in athletes (VOR: Athletes: 0.55 ± 0.15 vs. CONTROLS: 0.25 ± 0.18 mm, p<0.05). Athletes had superior handgrip strength (Athletes: 55.92 ± 17.06 vs. CONTROLS: 36.77 ± 17.06 kg, p<0.05) but similar heart rate responses at peak (Athletes: 123 ± 16 vs. CONTROLS: 130 ± 25 bpm, p>0.05) and 1 minute recovery (Athletes: 88 ± 21 vs. CONTROLS: 98 ± 26 bpm, p>0.05) following the step test. CONCLUSION: Elite power athletes have larger brachial arteries, and greater vasoreactivity (greater vasodilatory and constrictor responses) than age-matched controls, contributing to a significantly greater VOR. These data extend the existence of an 'athlete's artery' as previously shown for elite endurance athletes to elite power athletes, and presents a hypothetical explanation for the functional significance of the 'power athlete's artery'.