Best John R, Rosano Caterina, Aizenstein Howard J, Tian Qu, Boudreau Robert M, Ayonayon Hilsa N, Satterfield Suzanne, Simonsick Eleanor M, Studenski Stephanie, Yaffe Kristine, Liu-Ambrose Teresa
Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada; Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, Canada; Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada.
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
Neurobiol Aging. 2017 Sep;57:153-161. doi: 10.1016/j.neurobiolaging.2017.05.023. Epub 2017 Jun 6.
Previous studies have shown that more active older adults have better cognition and brain health based on a variety of structural neuroimaging measures. Nevertheless, the effects of maintaining physical activity (PA) over an extended period of time on future changes in older adults' cognition and brain structure are unknown. Participants were 141 initially well-functioning community-dwelling older adults (aged 70-79 years at baseline; 60% female; 42% black) studied over a 13-year period. PA (self-reported time spent walking) was assessed annually from years 1 to 10. Magnetic resonance imaging with diffusion tensor was performed at years 10 and 13. Time spent walking decreased on average by 8.4% annually from year 1 to year 10. Independent of initial time spent walking, demographics, and APOE e4 status, better maintenance of time spent walking over the decade predicted less reduction in hippocampal volume (p = 0.03), smaller increases in global gray matter mean diffusivity and white matter axial diffusivity (p < 0.01), and maintenance of general cognitive performance (p < 0.01). Maintenance of cognitive performance was associated with smaller increases in white matter axial diffusivity (p < 0.01). PA at baseline and at year 10, as well as changes in PA over a 5-year period, was less predictive of future changes in brain structure and cognition. Thus, how PA levels change over longer periods of aging may be an important contributor to cognitive and neural protection.
以往研究表明，根据多种结构性神经影像测量方法，身体更活跃的老年人具有更好的认知能力和大脑健康状况。然而，长期维持身体活动（PA）对老年人认知和脑结构未来变化的影响尚不清楚。研究对象为141名最初功能良好的社区居住老年人（基线年龄70 - 79岁；60%为女性；42%为黑人），研究时长为13年。从第1年到第10年每年评估PA（自我报告的步行时间）。在第10年和第13年进行磁共振扩散张量成像。从第1年到第10年，步行时间平均每年减少8.4%。不考虑初始步行时间、人口统计学因素和APOE e4状态，在这十年中更好地维持步行时间预示着海马体体积减少较少（p = 0.03），全脑灰质平均扩散率和白质轴向扩散率增加较小（p < 0.01），以及一般认知能力的维持（p < 0.01）。认知能力的维持与白质轴向扩散率增加较小有关（p < 0.01）。基线和第10年的PA，以及5年期间PA的变化，对未来脑结构和认知变化的预测性较低。因此，在更长的衰老过程中PA水平如何变化可能是认知和神经保护的一个重要因素。
