【論文摘要】Effects of Exercises on Cardiovascular Risks, Cardiorespiratory Fitness, Brain Structures, Brain Activation, Task-Switching Performance and Their Interrelationships in Middle-Aged and Older Adults With Cardiovascular Risks

【論文摘要】運動對具心血管危險因子之中老年人的心肺適能、心血管危險因子、腦結構與活化、及轉換任務表現的效果及效果間之關係

Chia-Hsin Liu(劉珈欣) ； Pei-Fang Tang(湯佩芳) ； Ssu-Yuan Chen(陳思遠) ； Joshua Goh(吳恩賜) ； Yu-Ling Chang(張玉玲)

《物理治療》 48卷2期 (2023/06) Pp. 144-145

https://doi.org/10.6215/FJPT.202306.P25

摘要

Background and Purpose: Cardiovascular risks (CVRs) have negative impacts on cognitive task-switching, brain structures, and brain activation patterns. Doing regular exercises may prevent these negative impacts from happening. In this study, we examined the effects of aerobic training (AT), Tai Chi Chuan (TCC), and stretching (ST) exercises and investigated whether exercise-induced changes in brain structures and brain activation would mediate the relationships of changes in CVRs or change in cardiorespiratory fitness (CRF) with changes in task-switching performance in middle-aged and older adults with CVRs. Methods: This was an assessor-blind randomized controlled clinical trial (Trial no: NCT03275038). Sedentary middle-aged and older adults with CVRs (mean age = 64.3 ± 7.4 years, range = 45-79 years) were recruited and randomly assigned to the AT, TCC, or ST group. All three groups received three one-hour exercise sessions weekly for 12 weeks under supervision. Blood tests for measuring CVRs, cardiorespiratory exercise tests for measuring CRF, MRI scans for collecting brain structures and functional images, and task-switching performance were collected at baseline and week 12 to compare differences among the three groups before and after training. Mediation analysis was applied to identify significant mediators between the relationships of changes in CVR or CRF and changes in task-switching performance. Results: All three groups significantly improved CRF, CVRs, and task-switching performance, and decreased brain activation at the left supplementary motor area while performing task-switching after the 12-week training (p < 0.05). The changes in brain activation at the right hippocampus fully mediated the relationships between the reductions of CVRs and the improved task-switching performance (Indirect effect = 0.020, 95% CI = [0.0011, 0.0470]). The changes in brain volume at the left inferior frontal gyrus fully mediated the relationships between the increases in CRF and the improved task-switching performance (Indirect effect = -0.124, 95% CI = [-0.347, -0.005]). Conclusions: Our results supported the protective roles of exercises, regardless of the type, in reducing CVRs and their negative health impacts. More importantly, exercise-induced brain structure and activation changes mediated the relationships of changes in CVR and CRF with changes in task-switching performance. Clinical Relevance: Brain structure and functional activations are important mediators of exercise effects on cognitive functions.