Departments of Exercise Science, Syracuse University, Syracuse, NY, United States.
Departments of Exercise Science, Syracuse University, Syracuse, NY, United States.
Exp Gerontol. 2018 Jan;101:54-62. doi: 10.1016/j.exger.2017.11.004. Epub 2017 Nov 10.
This study examined central artery stiffness and hemodynamic pulsatility during cognitive engagement in younger and older adults.
Vascular-hemodynamic measures were completed in 19 younger (age 35±1yrs) and 20 older (age 69±2yrs) adults at rest and during a Stroop task. Aortic stiffness (carotid-femoral pulse wave velocity, PWV) and carotid pulse pressure (PP) were assessed using applanation tonometry. Carotid stiffness was assessed as a single-point PWV using Doppler Ultrasound. Middle cerebral artery (MCA) mean flow and flow pulsatility index (PI) were assessed using transcranial Doppler. Cognitive function was assessed as accuracy and reaction time from the Stroop task.
Older adults had lower accuracy scores and longer reaction times on the Stroop task compared to younger adults (p<0.05). Both age groups had similar increases in MCA mean flow during Stroop (p<0.05). There were significant increases in aortic PWV, carotid PWV, carotid PP and MCA PI during Stroop in older but not younger adults (p<0.05). Carotid PP and MCA PI assessed during Stroop were statistical mediators of the association between age group and Stroop performance metrics (accuracy and reaction time, p<0.05), while aortic and carotid PWV were indirect statistical mediators of MCA PI through carotid PP (p<0.05).
Older adults experience increases in large artery stiffness during cognitive engagement possibly preventing effective buffering of pulsatile hemodynamic energy entry into the cerebrovasculature. This is important as pulsatile flow during cognitive engagement, and not mean flow per se, was related to overall cognitive performance.
本研究旨在探讨年轻和老年个体在认知任务时中心动脉僵硬度和血流动力学搏动性的变化。
19 名年轻成年人（年龄 35±1 岁）和 20 名老年成年人（年龄 69±2 岁）在静息和完成 Stroop 任务时完成了血管 - 血流动力学测量。应用平板压力技术评估主动脉僵硬度（颈股脉搏波速度，PWV）和颈动脉脉搏压（PP）。使用多普勒超声评估颈动脉僵硬度作为单点 PWV。使用经颅多普勒评估大脑中动脉（MCA）平均血流和血流搏动指数（PI）。Stroop 任务的准确性和反应时间用于评估认知功能。
与年轻成年人相比，老年成年人在 Stroop 任务中的准确性得分更低，反应时间更长（p<0.05）。两组在 Stroop 期间 MCA 平均血流均有相似的增加（p<0.05）。在 Stroop 期间，老年成年人的主动脉 PWV、颈动脉 PWV、颈动脉 PP 和 MCA PI 均显著增加，而年轻成年人则没有（p<0.05）。在 Stroop 期间评估的颈动脉 PP 和 MCA PI 是年龄组与 Stroop 表现指标（准确性和反应时间）之间关联的统计学中介，而主动脉和颈动脉 PWV 是通过颈动脉 PP 对 MCA PI 的间接统计学中介（p<0.05）。
老年成年人在认知任务时会出现大动脉僵硬度增加，这可能会阻止脉动血流动力学能量有效缓冲进入脑血管系统。这很重要，因为在认知任务时是脉动血流，而不仅仅是平均血流，与整体认知表现相关。
