Best John R, Dao Elizabeth, Churchill Ryan, Cosco Theodore D
Gerontology Research Centre, Simon Fraser University, Vancouver, BC, Canada.
Department of Gerontology, Simon Fraser University, Vancouver, BC, Canada.
Front Psychol. 2020 Nov 17;11:608049. doi: 10.3389/fpsyg.2020.608049. eCollection 2020.
A comprehensive analysis of associations between physical fitness and brain structure in young adulthood is lacking, and further, it is unclear the degree to which associations between physical fitness and brain health can be attributed to a common genetic pathway or to environmental factors that jointly influences physical fitness and brain health. This study examined genotype-confirmed monozygotic and dizygotic twins, along with non-twin full-siblings to estimate the contribution of genetic and environmental factors to variation within, and covariation between, physical fitness and brain structure. Participants were 1,065 young adults between the ages of 22 and 36 from open-access Young Adult Human Connectome Project (YA-HCP). Physical fitness was assessed by submaximal endurance (2-min walk test), grip strength, and body mass index. Brain structure was assessed using magnetic resonance imaging on a Siemens 3T customized 'Connectome Skyra' at Washington University in St. Louis, using a 32-channel Siemens head coil. Acquired T1-weighted images provided measures of cortical surface area and thickness, and subcortical volume following processing by the YA-HCP structural FreeSurfer pipeline. Diffusion weighted imaging was acquired to assess white matter tract integrity, as measured by fractional anisotropy, following processing by the YA-HCP diffusion pipeline and tensor fit. Following correction for multiple testing, body mass index was negatively associated with fractional anisotropy in various white matter regions of interest (all | | statistics > 3.9) and positively associated with cortical thickness within the right superior parietal lobe ( statistic = 4.6). Performance-based measures of fitness (i.e., endurance and grip strength) were not associated with any structural neuroimaging markers. Behavioral genetic analysis suggested that heritability of white matter integrity varied by region, but consistently explained >50% of the phenotypic variation. Heritability of right superior parietal thickness was large (∼75% variation). Heritability of body mass index was also fairly large (∼60% variation). Generally, to of the correlation between brain structure and body mass index could be attributed to heritability effects. Overall, this study suggests that greater body mass index is associated with lower white matter integrity, which may be due to common genetic effects that impact body composition and white matter integrity.
目前缺乏对青年期身体素质与脑结构之间关联的全面分析，此外，尚不清楚身体素质与脑健康之间的关联在多大程度上可归因于共同的遗传途径或共同影响身体素质和脑健康的环境因素。本研究对基因型确认的同卵双胞胎和异卵双胞胎以及非双胞胎的全同胞进行了检测，以估计遗传和环境因素对身体素质和脑结构内部变异以及两者之间协变的贡献。参与者是来自开放获取的青年成人人类连接组计划（YA-HCP）的1065名年龄在22岁至36岁之间的青年成人。通过次最大耐力（2分钟步行测试）、握力和体重指数来评估身体素质。在圣路易斯华盛顿大学使用西门子3T定制的“连接组Skyra”磁共振成像仪，采用32通道西门子头部线圈评估脑结构。获取的T1加权图像在经过YA-HCP结构FreeSurfer管道处理后，提供了皮质表面积、厚度以及皮质下体积的测量值。获取扩散加权成像以评估白质束完整性，通过分数各向异性测量，在经过YA-HCP扩散管道和张量拟合处理后得出。在进行多重检验校正后，体重指数与多个感兴趣的白质区域的分数各向异性呈负相关（所有| |统计量>3.9），与右侧顶上叶内的皮质厚度呈正相关（统计量=4.6）。基于表现的身体素质指标（即耐力和握力）与任何结构神经影像标记均无关联。行为遗传学分析表明，白质完整性的遗传力因区域而异，但始终解释了超过50%的表型变异。右侧顶上叶厚度的遗传力较大（约75%的变异）。体重指数的遗传力也相当大（约60%的变异）。一般来说，脑结构与体重指数之间相关性的 至 可归因于遗传效应。总体而言，本研究表明较高的体重指数与较低的白质完整性相关，这可能是由于影响身体组成和白质完整性的共同遗传效应所致。
