title: Passive leg movement-induced vasodilation in women: the impact of age.
abstract: Passive leg movement (PLM), an assessment of predominantly nitric oxide-dependent vasodilation, is decreased with age and cannot be augmented by posture-induced increases in femoral perfusion pressure in older men. However, this novel method of assessing vascular function has yet to be used to evaluate alterations in nitric oxide-dependent vasodilation with age in females. PLM was performed in 10 young (20 ± 1 yr) and 10 old (73 ± 2 yr) women in both the supine and upright-seated postures, whereas central and peripheral hemodynamic measurements were acquired second by second using noninvasive techniques (finger photoplethysmography and Doppler ultrasound, respectively). The heart rate response to PLM was attenuated in the old compared with the young in both the supine (young, 10 ± 1; and old, 5 ± 1 beats/min; P < 0.05) and upright-seated posture (young, 10 ± 2; and old, 5 ± 1 beats/min; P < 0.05), leading to a blunted cardiac output response in the old in the upright-seated posture (young, 1.0 ± 0.2; and old, 0.3 ± 0.1 l/min; P < 0.05). The PLM-induced peak change in leg vascular conductance was lower in the old compared with the young in both postures (young supine, 5.7 ± 0.5; old supine, 2.6 ± 0.3; young upright, 9.2 ± 0.7; and old upright, 2.2 ± 0.4 ml·min(-1)·mmHg(-1); P < 0.05) and was significantly augmented by the upright-seated posture in the young only, revealing a vasodilatory reserve capacity in the young (3.5 ± 0.6 ml·min(-1)·mmHg(-1), P < 0.05) that was absent in the old (-0.5 ± 0.3 ml·min(-1)·mmHg(-1), P = 0.18). These data support previous literature demonstrating attenuated PLM-induced vasodilation with age and extend these findings to include the female population, thus bolstering the utility of PLM as a novel assessment of vascular function across the life span in humans.
authors.affiliation: Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah;
authors.forename: H Jonathan
authors.initials: HJ
authors.lastname: Groot
authors.affiliation: Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah;
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Rossman
authors.affiliation: Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Internal Medicine, University of Utah, Salt Lake City, Utah; and.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Trinity
authors.affiliation: Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Internal Medicine, University of Utah, Salt Lake City, Utah; and.
authors.forename: Gwenael
authors.initials: G
authors.lastname: Layec
authors.affiliation: Department of Health and Exercise Sciences, Skidmore College, Saratoga Springs, New York.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Ives
authors.affiliation: Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah; Department of Internal Medicine, University of Utah, Salt Lake City, Utah; and r.richardson@hsc.utah.edu.
authors.forename: Russell S
authors.initials: RS
authors.lastname: Richardson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D002302:Cardiac Output; D005260:Female; D006339:Heart Rate; D006801:Humans; D007866:Leg / Q000098:blood supply / Q000254:growth & development / Q000502:physiology*; D009068:Movement; D011187:Posture; D014664:Vasodilation
keywords: endothelium; passive leg movement; posture; vascular function