与衰老过程中大脑灌注相关的加速度计测量的身体活动和久坐时间的剂量依赖性关联。
Dose-dependent association of accelerometer-measured physical activity and sedentary time with brain perfusion in aging.
机构信息
Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr. La Jolla, CA 92093. USA.
San Diego State University, San Diego Joint Doctoral Program in Clinical Psychology, San Diego, CA 92093, USA.
出版信息
Exp Gerontol. 2019 Oct 1;125:110679. doi: 10.1016/j.exger.2019.110679. Epub 2019 Aug 2.
INTRODUCTION
Age-related decreases in cerebral blood flow (CBF) may lead to cognitive decline, while physical activity (PA) can maintain CBF and cognition in aging. The intensity of PA needed to affect CBF in aging, and the independent effects of sedentary time on CBF are currently unknown. Moreover, research conducted in free-living environments with objective measures of PA (e.g., accelerometry) is lacking.
METHODS
This cross-sectional study used accelerometry to objectively measure sedentary time, all light PA [AllLightPA], moderate-to-vigorous PA [MVPA], and total activity counts [TAC] in 52 cognitively healthy older adults. Robust linear regressions investigated the association of CBF (using arterial spin labeling magnetic resonance imaging) in frontal and medial temporal regions, with each PA intensity and sedentary time.
RESULTS
Greater sedentary time was significantly associated with lower CBF in lateral and medial frontal regions after adjusting for MVPA, while higher AllLightPA (adjusted for MVPA), MVPA (adjusted for AllLightPA), and TAC were associated with greater CBF in lateral and medial frontal regions.
DISCUSSION
Lighter activities, as well as MVPA, are beneficial to CBF in brain regions typically affected by the aging process and malleable to exercise interventions (i.e., the frontal lobes), whereas sedentary time is an independent risk factor for neurovascular dysregulation in normal aging.
简介
与年龄相关的大脑血流（CBF）减少可能导致认知能力下降，而身体活动（PA）可以维持衰老过程中的 CBF 和认知能力。目前尚不清楚在衰老过程中影响 CBF 所需的 PA 强度，以及久坐时间对 CBF 的独立影响。此外，缺乏在具有客观 PA 测量（例如，加速度计）的自由生活环境中进行的研究。
方法
这项横断面研究使用加速度计客观测量久坐时间、所有低强度 PA[AllLightPA]、中等到剧烈 PA[MVPA]和总活动计数[TAC]，共纳入 52 名认知健康的老年人。稳健线性回归分析了 CBF（使用动脉自旋标记磁共振成像）与每种 PA 强度和久坐时间在额叶和内侧颞叶区域的相关性。
结果
调整 MVPA 后，久坐时间与外侧和内侧额叶区域的 CBF 降低显著相关，而更高的 AllLightPA（调整 MVPA）、MVPA（调整 AllLightPA）和 TAC 与外侧和内侧额叶区域的 CBF 增加相关。
讨论
与 MVPA 相比，较轻的活动对大脑区域的 CBF 更有益，这些区域通常受到衰老过程的影响，并且可以通过运动干预来改变（即额叶），而久坐时间是正常衰老过程中神经血管调节失调的独立危险因素。
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