From the Population Health Sciences (F.A.U.F., H.L., M.M.B.B., N.A.A.), German Center for Neurodegenerative Diseases (DZNE), Bonn; Image Analysis (K.D., M.R.), German Center for Neurodegenerative Diseases (DZNE), Bonn; Institute for Medical Biometry (A.M., M.M.B.B.), Informatics and Epidemiology (IMBIE), Faculty of Medicine, University of Bonn, Germany; A.A. Martinos Center for Biomedical Imaging (M.R.), Massachusetts General Hospital, Boston; Department of Radiology (M.R.), Harvard Medical School, Boston, MA; and Department of Neurology (N.A.A.), Faculty of Medicine, University of Bonn, Germany.
Neurology. 2022 Sep 13;99(11):e1202-e1215. doi: 10.1212/WNL.0000000000200884. Epub 2022 Aug 2.
While there is growing evidence that physical activity promotes neuronal health, studies examining the relation between physical activity and brain morphology remain inconclusive. We therefore examined whether objectively quantified physical activity is related to brain volume, cortical thickness, and gray matter density in a large cohort study. In addition, we assessed molecular pathways that may underlie the effects of physical activity on brain morphology.
We used cross-sectional baseline data from 2,550 eligible participants (57.6% women; mean age: 54.7 years, range: 30-94 years) of a prospective cohort study. Physical activity dose (metabolic equivalent hours and step counts) and intensity (sedentary and light-intensity and moderate-to-vigorous intensity activities) were recorded with accelerometers. Brain volumetric, gray matter density, and cortical thickness measures were obtained from 3T MRI scans using FreeSurfer and Statistical Parametric Mapping. The relation of physical activity (independent variable) and brain structure (outcome) was examined with polynomial multivariable regression, while adjusting for age, sex, intracranial volume, education, and smoking. Using gene expression profiles from the Allen Brain Atlas, we extracted molecular signatures associated with the effects of physical activity on brain morphology.
Physical activity dose and intensity were independently associated with larger brain volumes, gray matter density, and cortical thickness of several brain regions. The effects of physical activity on brain volume were most pronounced at low physical activity quantities and differed between men and women and across age. For example, more time spent in moderate-to-vigorous intensity activities was associated with greater total gray matter volume, but the relation leveled off with more activity (standardized β [95% CIs]: 1.37 [0.35-2.39] and -0.70 [-1.25 to -0.15] for the linear and quadratic terms, respectively). The strongest effects of physical activity were observed in motor regions and cortical regions enriched for genes involved in mitochondrial respiration.
Our findings suggest that physical activity benefits brain health, with the strongest effects in motor regions and regions with a high oxidative demand. While young adults may particularly profit from additional high-intensity activities, older adults may already benefit from light-intensity activities. Physical activity and reduced sedentary time may be critical in the prevention of age-associated brain atrophy and neurodegenerative diseases.
虽然越来越多的证据表明身体活动有益于神经元健康，但研究身体活动与大脑形态之间的关系仍然没有定论。因此，我们在一项大型队列研究中检验了身体活动的客观量化指标与大脑体积、皮质厚度和灰质密度之间的关系。此外，我们还评估了可能作为身体活动对大脑形态影响的潜在机制的分子途径。
我们使用前瞻性队列研究中 2550 名合格参与者（57.6%为女性；平均年龄 54.7 岁，范围 30-94 岁）的横断面基线数据。使用加速度计记录身体活动剂量（代谢当量小时和步数）和强度（久坐、低强度和中高强度活动）。通过使用 FreeSurfer 和统计参数映射从 3T MRI 扫描中获得大脑容积、灰质密度和皮质厚度测量值。使用多项式多变量回归检验身体活动（自变量）和大脑结构（结果）之间的关系，同时调整年龄、性别、颅内体积、教育程度和吸烟情况。我们从 Allen 大脑图谱中提取与身体活动对大脑形态影响相关的分子特征。
身体活动剂量和强度与几个大脑区域的大脑体积、灰质密度和皮质厚度增加独立相关。身体活动对大脑体积的影响在低身体活动量时最为明显，且在男性和女性以及不同年龄之间存在差异。例如，更多的中高强度活动时间与总灰质体积增加有关，但随着活动量的增加，这种关系趋于平稳（线性项的标准化β[95%CI]：1.37[0.35-2.39]和二次项：-0.70[-1.25 至 -0.15]）。身体活动的最强影响发生在运动区域和富含涉及线粒体呼吸的基因的皮质区域。
我们的研究结果表明，身体活动有益于大脑健康，在运动区域和高氧化需求区域的效果最强。虽然年轻成年人可能特别受益于额外的高强度活动，但老年人可能已经从低强度活动中受益。身体活动和减少久坐时间可能是预防与年龄相关的脑萎缩和神经退行性疾病的关键。
