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This Article Full Text Full Text (PDF) All Versions of this Article: 297/3/H1109    most recent 00226.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Black, M. A. Articles by Green, D. J. PubMed PubMed Citation Articles by Black, M. A. Articles by Green, D. J.

Impact of age, sex, and exercise on brachial artery flow-mediated dilatation

¹Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, United Kingdom; ²Department of Physiology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands; and ³School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia

Submitted 6 March 2009 ; accepted in final form 18 July 2009

Flow-mediated dilatation (%FMD), an index of nitric oxide (NO)-mediated vasodilator function, is regarded as a surrogate marker of cardiovascular disease. Aging is associated with endothelial dysfunction, but underlying sex-related differences may exist and the effects of fitness and exercise on endothelial dysfunction in men (M) and women (W) are poorly understood. We compared %FMD of the brachial artery in 18 young [Y, 26 ± 1 yr; 9 M and 9 W], 12 older fit (OF, 57 ± 2 yr; 6 M and 6 W), and 16 older sedentary (OS, 59 ± 2 yr; 8 M and 8 W) subjects. Glyceryl trinitrate (GTN) administration was used to assess endothelium-independent vasodilatation, and the FMD-to-GTN ratio was calculated to characterize NO dilator function in the context of smooth muscle cell sensitivity. Brachial %FMD in Y (7.1 ± 0.8%) was significantly higher compared with OS (4.8 ± 0.7%, P < 0.05), but not OF (6.4 ± 0.7%). Differences between Y and OS subjects were due primarily to lower FMD in the OS women (4.3 ± 0.6%). OS women exhibited significantly lower FMD-to-GTN ratios compared with Y (P < 0.05) and OF women (P < 0.05), whereas these differences were not apparent in men. Exercise training improved brachial artery NO dilator function (FMD-to-GTN ratio) after 24 wk (P < 0.05) in OS women, but not men. These findings indicate that maintaining a high level of fitness, or undertaking exercise training, prevents the age-related decline in the brachial artery vasodilator function evident in women. In OS men, who had relatively preserved NO dilator function, no training adaptations were observed. This study has potential implications for the prevention of conduit artery endothelial dysfunction in men and women.

fitness; exercise training; upper-limb nitric oxide dilator function