PURPOSE: To assess sympathetic vasomotor activity and its changes with age, using pulsed wave Doppler ultrasound. METHODS: We recruited 20 young adults (24-37 years old) and 20 older individuals (60-81 years old). Pulsed wave Doppler ultrasound was applied over the right radial artery to measure blood flow at rest and after a voluntary inspiratory cough eliciting sympathetic activation. The maximal (Vmax), minimal (Vmin), time-averaged (TAMaxV) blood flow velocity, and the pulsatility index (PI) were calculated and compared between groups. RESULTS: At rest, PI was similar in both groups but Vmax and TAMaxV were higher in the older group (p < 0.05). Vmax, Vmin, and TAMaxV decreased, and PI increased after inspiratory cough in both groups (p ≤ 0.001), but this increase was lower in the older group (p < 0.001). TAMaxV after coughing was higher in the older group (p < 0.05). Heart rate did not differ significantly within or between groups. CONCLUSIONS: The older group exhibited reduced vasomotor reactivity of the radial artery after sympathetic stimulus. Peripheral vasomotor response should be interpreted with caution in elderly populations.
PURPOSE: To assess sympathetic vasomotor activity and its changes with age, using pulsed wave Doppler ultrasound. METHODS: We recruited 20 young adults (24-37 years old) and 20 older individuals (60-81 years old). Pulsed wave Doppler ultrasound was applied over the right radial artery to measure blood flow at rest and after a voluntary inspiratory cough eliciting sympathetic activation. The maximal (Vmax), minimal (Vmin), time-averaged (TAMaxV) blood flow velocity, and the pulsatility index (PI) were calculated and compared between groups. RESULTS: At rest, PI was similar in both groups but Vmax and TAMaxV were higher in the older group (p < 0.05). Vmax, Vmin, and TAMaxV decreased, and PI increased after inspiratory cough in both groups (p ≤ 0.001), but this increase was lower in the older group (p < 0.001). TAMaxV after coughing was higher in the older group (p < 0.05). Heart rate did not differ significantly within or between groups. CONCLUSIONS: The older group exhibited reduced vasomotor reactivity of the radial artery after sympathetic stimulus. Peripheral vasomotor response should be interpreted with caution in elderly populations.
Authors: Hesamoddin Jahanian; Wendy W Ni; Thomas Christen; Michael E Moseley; Manjula Kurella Tamura; Greg Zaharchuk Journal: PLoS One Date: 2014-03-20 Impact factor: 3.240