Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU (Norwegian University of Science and Technology), Trondheim, Norway.
Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Clin Interv Aging. 2021 Aug 12;16:1485-1501. doi: 10.2147/CIA.S318679. eCollection 2021.
The aim was to examine the effect of a 5-year exercise intervention at different intensities on brain structure in older adults from the general population partaking in the randomized controlled trial Generation 100 Study.
Generation 100 Study participants were invited to a longitudinal neuroimaging study before randomization. A total of 105 participants (52 women, 70-77 years) volunteered. Participants were randomized into supervised exercise twice a week performing high intensity interval training in 4×4 intervals at ~90% peak heart rate (HIIT, n = 33) or 50 minutes of moderate intensity continuous training at ~70% of peak heart rate (MICT, n = 24). The control group (n = 48) followed the national physical activity guidelines of ≥30 min physical activity daily. Brain MRI at 3T, clinical and cardiorespiratory fitness (CRF), measured as peak oxygen uptake, were collected at baseline, and after 1, 3, and 5 years of intervention. Brain volumes and cortical thickness were derived from T1 weighted 3D MRI data using FreeSurfer. The effect of HIIT or MICT on brain volumes over time was investigated with linear mixed models, while linear regressions examined the effect of baseline CRF on brain volumes at later time points.
Adherence in each group was between 79 and 94% after 5 years. CRF increased significantly in all groups during the first year. Compared to controls, the HIIT group had significantly increased hippocampal atrophy located to CA1 and hippocampal body, though within normal range, and the MICT group greater thalamic atrophy. No other effects of intervention group were found. CRF across the intervention was not associated with brain structure, but CRF at baseline was positively associated with cortical volume at all later time points.
Higher baseline CRF reduced 5-year cortical atrophy rate in older adults, while following physical activity guidelines was associated with the lowest hippocampal and thalamic atrophy rates.
本研究旨在探讨一项为期 5 年、不同强度的运动干预对参与随机对照试验 Generation 100 研究的普通人群中老年大脑结构的影响。
Generation 100 研究的参与者在随机分组前被邀请参加一项纵向神经影像学研究。共有 105 名参与者（52 名女性，70-77 岁）自愿参加。参与者被随机分为两组，每周进行两次监督下的运动，高强度间歇训练组（HIIT，n = 33）进行 4×4 个约 90%峰值心率的间隔训练，中等强度持续训练组（MICT，n = 24）进行约 70%峰值心率的 50 分钟训练。对照组（n = 48）遵循国家体育活动指南，每天进行≥30 分钟的体育活动。在基线、1 年、3 年和 5 年后，采集 3T 脑 MRI、临床和心肺功能（CRF），以峰值摄氧量来衡量。使用 FreeSurfer 从 T1 加权 3D MRI 数据中得出脑容量和皮质厚度。采用线性混合模型探讨 HIIT 或 MICT 对脑容量随时间的影响，线性回归分析基线 CRF 对后期时间点脑容量的影响。
5 年后，各组的依从性在 79%至 94%之间。所有组的 CRF 在第一年都显著增加。与对照组相比，HIIT 组 CA1 和海马体的海马萎缩明显增加，尽管仍在正常范围内，而 MICT 组的丘脑萎缩更为明显。干预组没有其他影响。整个干预过程中 CRF 与脑结构无关，但基线 CRF 与所有后续时间点的皮质体积呈正相关。
较高的基线 CRF 降低了老年人大脑皮质的 5 年萎缩率，而遵循体育活动指南与海马和丘脑萎缩率最低有关。
