Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
J Gerontol A Biol Sci Med Sci. 2023 Mar 1;78(3):545-553. doi: 10.1093/gerona/glac149.
Myelin loss is a feature of cerebral small vessel disease (cSVD). Although physical activity levels may exert protective effects over cSVD pathology, its specific relationship with myelin content in people living with the cSVD is unknown. Thus, we investigated whether physical activity levels are associated with myelin in community-dwelling older adults with cSVD and mild cognitive impairment.
Cross-sectional data from 102 individuals with cSVD and mild cognitive impairment were analyzed (mean age [SD] = 74.7 years [5.5], 63.7% female). Myelin was measured using a magnetic resonance gradient and spin echo sequence. Physical activity was estimated using the Physical Activity Scale for the Elderly. Hierarchical regression models adjusting for total intracranial volume, age, sex, body mass index, and education were conducted to determine the associations between myelin content and physical activity. Significant models were further adjusted for white matter hyperintensity volume.
In adjusted models, greater physical activity was linked to higher myelin content in the whole-brain white matter (R2change = .04, p = .048). Greater physical activity was also associated with myelin content in the sagittal stratum (R2change = .08, p = .004), anterior corona radiata (R2change = .04, p = .049), and genu of the corpus callosum (R2change = .05, p = .018). Adjusting for white matter hyperintensity volume did not change any of these associations.
Physical activity may be a strategy to maintain myelin in older adults with cSVD and mild cognitive impairment. Future randomized controlled trials of exercise are needed to determine whether exercise increases myelin content.
髓鞘丢失是脑小血管病（cSVD）的特征。尽管身体活动水平可能对 cSVD 病理产生保护作用，但它与患有 cSVD 和轻度认知障碍的人群中的髓鞘含量的具体关系尚不清楚。因此，我们研究了身体活动水平与社区居住的患有 cSVD 和轻度认知障碍的老年人的髓鞘之间是否存在关联。
分析了 102 名患有 cSVD 和轻度认知障碍的个体的横断面数据（平均年龄[标准差] = 74.7 岁[5.5]，63.7%为女性）。使用磁共振梯度和自旋回波序列测量髓鞘。使用老年人身体活动量表估计身体活动。进行分层回归模型，调整总颅内体积、年龄、性别、体重指数和教育程度，以确定髓鞘含量与身体活动之间的关联。对显著模型进一步调整了脑白质高信号体积。
在调整后的模型中，更多的身体活动与全脑白质的髓鞘含量更高相关（R2 变化=.04，p =.048）。更多的身体活动也与矢状层（R2 变化=.08，p =.004）、前冠状辐射（R2 变化=.04，p =.049）和胼胝体膝部（R2 变化=.05，p =.018）的髓鞘含量相关。调整脑白质高信号体积并没有改变这些关联中的任何一个。
身体活动可能是维持患有 cSVD 和轻度认知障碍的老年人髓鞘的一种策略。需要进行关于锻炼的随机对照试验，以确定锻炼是否会增加髓鞘含量。
