Heffernan Matthew J, Patel Hardikkumar M, Muller Matthew D
Pennsylvania State University College of Medicine, Penn State Hershey Heart and Vascular Institute, 500 University Drive, Hershey, 17033, Pennsylvania.
Physiol Rep. 2013 Dec 5;1(7):e00180. doi: 10.1002/phy2.180. eCollection 2013 Dec 1.
Forearm vascular conductance (FVC) increases in response to mental stress (verbal mental arithmetic) in young people. However, the effect of healthy aging and mental stress on FVC is unknown. In this study, we tested the hypothesis that FVC and cutaneous vascular conductance (CVC) would be attenuated in older adults compared to young adults. In 13 young (27 ± 1 year) and 11 older (62 ± 1 year) subjects, we quantified heart rate (HR), mean arterial pressure (MAP), FVC (Doppler ultrasound), and CVC (laser Doppler flowmetry) in response to a 3-min bout of mental stress in the supine posture. Changes from baseline were compared between groups and physiological variables were also correlated. Older adults had a blunted HR response to mental stress (Δ = 7 ± 2 vs. 14 ± 2 beats/min) but ΔMAP was comparable between groups (Δ = 11 ± 2 mmHg vs. 9 ± 1). During the third minute of mental stress, the %ΔFVC (-2 ± 5 vs. 31 ± 12%) and %ΔCVC (2 ± 6 vs. 31 ± 15%) were both impaired in older adults compared to young subjects. There was no relationship between ΔHR and %ΔCVC in either group, but there was a positive relationship between ΔHR and %ΔFVC in both young subjects (R = 0.610, P < 0.027) and older subjects (R = 0.615, P < 0.044), such that larger tachycardia was associated with higher forearm vasodilation. These data indicate that older adults have impaired forearm vasodilation in response to mental stress.
年轻人的前臂血管传导率（FVC）会因精神压力（口头心算）而升高。然而，健康衰老和精神压力对FVC的影响尚不清楚。在本研究中，我们检验了这样一个假设：与年轻人相比，老年人的FVC和皮肤血管传导率（CVC）会降低。在13名年轻受试者（27±1岁）和11名老年受试者（62±1岁）中，我们在仰卧姿势下，对他们在3分钟精神压力期间的心率（HR）、平均动脉压（MAP）、FVC（多普勒超声）和CVC（激光多普勒血流仪）进行了量化。比较了两组之间相对于基线的变化，并对生理变量进行了相关性分析。老年人对精神压力的HR反应减弱（Δ=7±2对14±2次/分钟），但两组之间的ΔMAP相当（Δ=11±2 mmHg对9±1）。在精神压力的第三分钟，与年轻受试者相比，老年人的%ΔFVC（-2±5对31±12%）和%ΔCVC（2±6对31±15%）均受损。两组中ΔHR与%ΔCVC之间均无关系，但在年轻受试者（R=0.610，P<0.027）和老年受试者（R=0.615，P<0.044）中，ΔHR与%ΔFVC之间均呈正相关，即较大的心动过速与较高的前臂血管舒张相关。这些数据表明，老年人在面对精神压力时前臂血管舒张功能受损。
