Exercise-induced brachial artery vasodilation: effects of antioxidants and exercise training in elderly men

1 Department of Medicine, Division of Geriatrics, and 2 Department of Exercise and Sport Science, University of Utah, Salt Lake City; 3 Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah; 4 Faculty of Health, Science and Sport, University of Glamorgan, Mid-Galmorgan, Wales; 5 Department of Integrative Physiology, University of Colorado at Boulder, Boulder, Colorado; and 6 Department of Medicine, Division of Cardiovascular Medicine, Stanford University, Palo Alto, California Submitted August 17, 2009 ; accepted in final form December 1, 2009 Aging, vascular function, and exercise are thought to have a common link in oxidative stress. Of the 28 subjects studied (young, 26 ± 2 yr; old, 71 ± 6 yr), 12 took part in a study to validate an antioxidant cocktail (AOC: vitamins C, E, and -lipoic acid), while the remaining 8 young and 8 old subjects performed submaximal forearm handgrip exercise with placebo or AOC. Old subjects repeated forearm exercise with placebo or AOC following knee-extensor (KE) exercise training. Brachial arterial diameter and blood velocity (Doppler ultrasound) were measured at rest and during exercise. During handgrip exercise, brachial artery vasodilation in the old subjects was attenuated compared with that in young subjects following placebo (maximum = 3.0 and 6.0%, respectively). In contrast to the previously documented attenuation in exercise-induced brachial artery vasodilation in the young group with AOC, in the old subjects the AOC restored vasodilation (maximum = 7.0%) to match the young. KE training also improved exercise-induced brachial artery vasodilation. However, in the trained state, AOC administration no longer augmented brachial artery vasodilation in the elderly, but rather attenuated it. These data reveal an age-related pro-/antioxidant imbalance that impacts vascular function and show that exercise training is capable of restoring equilibrium such that vascular function is improved and the AOC-mediated reduction in free radicals now negatively impacts brachial artery vasodilation, as seen in the young. aging; free radicals; oxidative stress; arterial function Address for reprint requests and other correspondence: R. S. Richardson, Dept. of Medicine, Division of Geriatrics, Univ. of Utah, UT 84132-0001 (e-mail: r.richardson{at}hsc.utah.edu ).