title: Vascular function assessed by passive leg movement and flow-mediated dilation: initial evidence of construct validity.
abstract: The vasodilatory response to passive leg movement (PLM) appears to provide a novel, noninvasive assessment of vascular function. However, PLM has yet to be compared with the established noninvasive assessment of vascular health, flow-mediated dilation (FMD). Therefore, as an initial evaluation of the construct validity of PLM and upright seated and supine PLM as well as brachial (BA) and superficial femoral (SFA) artery FMDs were performed in 10 young (22 ± 1) and 30 old (73 ± 2) subjects. During upright seated PLM, the peak change in leg blood flow (ΔLBF) and leg vascular conductance (ΔLVC) was significantly correlated with BA (r = 0.57 and r = 0.66) and SFA (r = 0.44 and r = 0.41, ΔLBF and ΔLVC, respectively) FMD. Furthermore, although the relationships were not as strong, the supine PLM response was also significantly correlated with BA (r = 0.38 and r = 0.35) and SFA (r = 0.39 and r = 0.35, ΔLBF and ΔLVC, respectively) FMD. Examination of the young and old separately, however, revealed that significant relationships persisted in both groups only for the upright seated PLM response and BA FMD (young: r = 0.73 and r = 0.77; old: r = 0.35 and r = 0.45, ΔLBF and ΔLVC, respectively). Normalizing FMD for shear rate during PLM abrogated all significant relationships between the PLM and FMD response, suggesting a role for nitric oxide (NO) in these associations. Collectively, these data indicate that PLM, particularly upright seated PLM, likely provides an index of vascular health analogous to the traditional FMD test. Given the relative ease of PLM implementation, these data have important positive implications for PLM as a clinical vascular health assessment.
authors.affiliation: Geriatric Research, Education, and Clinical Center, George E. Whalen 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, George E. Whalen 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, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah.
authors.forename: Ryan S
authors.initials: RS
authors.lastname: Garten
authors.affiliation: Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah.
authors.forename: Melissa A H
authors.initials: MA
authors.lastname: Witman
authors.affiliation: Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; r.richardson@hsc.utah.edu.|Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah; and.|Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.
authors.forename: Russell S
authors.initials: RS
authors.lastname: Richardson
mesh_terms: D000367:Age Factors; D000368:Aged; D001916:Brachial Artery / Q000502:physiology*; D004730:Endothelium, Vascular / Q000502:physiology; D005263:Femoral Artery / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D009068:Movement / Q000502:physiology*; D009569:Nitric Oxide; D011187:Posture; D012039:Regional Blood Flow / Q000502:physiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016683:Supine Position; D014664:Vasodilation / Q000502:physiology*; D055815:Young Adult
chemical_list: D009569:Nitric Oxide
keywords: aging; cardiovascular disease; endothelium; nitric oxide