Department of Psychology, York University , Toronto, Ontario , Canada.
Laboratory of Brain and Cognition, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University , Montreal, Quebec , Canada.
J Appl Physiol (1985). 2019 Apr 1;126(4):1032-1041. doi: 10.1152/japplphysiol.01046.2018. Epub 2019 Jan 31.
We investigated sex differences in the association between a measure of physical health, cardiorespiratory fitness (CRF), and brain function using resting-state functional connectivity fMRI. We examined these sex differences in the default, frontoparietal control, and cingulo-opercular networks, assemblies of functionally connected brain regions known to be impacted by both age and fitness level. Healthy older adults ( n = 49; 29 women) were scanned to obtain measures of intrinsic connectivity within and across these 3 networks. We calculated global efficiency (a measure of network integration) and local efficiency (a measure of network specialization) using graph theoretical methods. Across all three networks combined, local efficiency was positively associated with CRF, and this was more robust in male versus female older adults. Furthermore, global efficiency was negatively associated with CRF, but only in males. Our findings suggest that in older adults, associations between brain network integrity and physical health are sex-dependent. These results underscore the importance of considering sex differences when examining associations between fitness and brain function in older adulthood. NEW & NOTEWORTHY We examined the association between cardiorespiratory fitness and resting state functional connectivity in several brain networks known to be impacted by age and fitness level. We found significant associations between fitness and measures of network integration and network specialization, but in a sex-dependent manner, highlighting the interplay between sex differences, fitness, and aging brain health. Our findings underscore the importance of considering sex differences when examining associations between fitness and brain function in older adulthood.
我们使用静息态功能连接 fMRI 研究了身体健康指标——心肺功能（CRF）与大脑功能之间的关联在性别上的差异。我们在默认状态、额顶控制和扣带回-顶叶网络中检查了这些性别差异，这些网络是由已知受年龄和健康水平影响的功能连接的脑区组成的集合。我们对健康的老年成年人（n=49；女性 29 名）进行了扫描，以获得这 3 个网络内和网络间的内在连接的测量值。我们使用图论方法计算了全局效率（网络整合的度量）和局部效率（网络专业化的度量）。在所有三个网络的组合中，局部效率与 CRF 呈正相关，而在男性和女性老年成年人中，这种相关性更为显著。此外，全局效率与 CRF 呈负相关，但仅在男性中如此。我们的研究结果表明，在老年成年人中，大脑网络完整性与身体健康之间的关联是具有性别依赖性的。这些结果强调了在研究健康水平与老年期大脑功能之间的关联时考虑性别的重要性。
