Burzynska Agnieszka Z, Jiao Yuqin, Knecht Anya M, Fanning Jason, Awick Elizabeth A, Chen Tammy, Gothe Neha, Voss Michelle W, McAuley Edward, Kramer Arthur F
Department of Human Development and Family Studies, Molecular, Cellular and Integrative Neurosciences, Colorado State UniversityFort Collins, CO, USA; The Beckman Institute for Advanced Science and Technology at the University of IllinoisUrbana, IL, USA.
Department of Human Development and Family Studies, Molecular, Cellular and Integrative Neurosciences, Colorado State University Fort Collins, CO, USA.
Front Aging Neurosci. 2017 Mar 16;9:59. doi: 10.3389/fnagi.2017.00059. eCollection 2017.
Degeneration of cerebral white matter (WM), or structural disconnection, is one of the major neural mechanisms driving age-related decline in cognitive functions, such as processing speed. Past cross-sectional studies have demonstrated beneficial effects of greater cardiorespiratory fitness, physical activity, cognitive training, social engagement, and nutrition on cognitive functioning and brain health in aging. Here, we collected diffusion magnetic resonance (MRI) imaging data from 174 older (age 60-79) adults to study the effects of 6-months lifestyle interventions on WM integrity. Healthy but low-active participants were randomized into Dance, Walking, Walking + Nutrition, and Active Control (stretching and toning) intervention groups (NCT01472744 on ClinicalTrials.gov). Only in the fornix there was a time × intervention group interaction of change in WM integrity: integrity declined over 6 months in all groups but increased in the Dance group. Integrity in the fornix at baseline was associated with better processing speed, however, change in fornix integrity did not correlate with change in processing speed. Next, we observed a decline in WM integrity across the majority of brain regions in all participants, regardless of the intervention group. This suggests that the aging of the brain is detectable on the scale of 6-months, which highlights the urgency of finding effective interventions to slow down this process. Magnitude of WM decline increased with age and decline in prefrontal WM was of lesser magnitude in older adults spending less time sedentary and more engaging in moderate-to-vigorous physical activity. In addition, our findings support the anterior-to-posterior gradient of greater-to-lesser decline, but only in the in the corpus callosum. Together, our findings suggest that combining physical, cognitive, and social engagement (dance) may help maintain or improve WM health and more physically active lifestyle is associated with slower WM decline. This study emphasizes the importance of a physically active and socially engaging lifestyle among aging adults.
脑白质（WM）的退化，即结构性连接中断，是导致与年龄相关的认知功能衰退（如处理速度）的主要神经机制之一。过去的横断面研究表明，较高的心肺适能、体育活动、认知训练、社交参与和营养对老年人的认知功能和大脑健康具有有益影响。在此，我们收集了174名年龄较大（60 - 79岁）成年人的扩散磁共振成像（MRI）数据，以研究为期6个月的生活方式干预对WM完整性的影响。健康但活动量低的参与者被随机分为舞蹈组、步行组、步行 + 营养组和主动对照组（伸展和塑形）（ClinicalTrials.gov上的NCT01472744）。仅在穹窿中存在WM完整性变化的时间×干预组交互作用：所有组的WM完整性在6个月内均下降，但舞蹈组有所增加。基线时穹窿的完整性与更好的处理速度相关，然而，穹窿完整性的变化与处理速度的变化并无关联。接下来，我们观察到所有参与者的大多数脑区WM完整性均下降，无论其所属干预组如何。这表明在6个月的时间尺度上可检测到大脑的老化，这凸显了寻找有效干预措施以减缓这一过程的紧迫性。WM下降的幅度随年龄增长而增加，而久坐时间较少且更多参与中度至剧烈体育活动的老年人，其前额叶WM的下降幅度较小。此外，我们的研究结果支持从前到后下降程度由大到小的梯度，但仅在胼胝体中存在。总之，我们的研究结果表明，将身体、认知和社交参与（舞蹈）相结合可能有助于维持或改善WM健康，且更积极的生活方式与WM下降较慢相关。本研究强调了老年人积极运动和社交参与的生活方式的重要性。
