In aging humans, aerobic exercise interventions have been found to be associated with more positive or less negative changes in frontal and temporal brain areas, such as the anterior cingulate cortex (ACC) and hippocampus, relative to no-exercise control conditions. However, individual measures such as gray-matter (GM) probability may afford less reliable and valid conclusions about maintenance or losses in structural brain integrity than a latent construct based on multiple indicators. Here, we established a latent factor of GM structural integrity based on GM probability assessed by voxel-based morphometry, magnetization transfer saturation, and mean diffusivity. Based on this latent factor, we investigated changes in structural brain integrity during a six-month exercise intervention in brain regions previously reported in studies using volumetric approaches. Seventy-five healthy, previously sedentary older adults aged 63–76 years completed an at-home intervention study in either an exercise group (EG; n = 40) or in an active control group (ACG; n = 35). Measures of peak oxygen uptake (VO₂peak) taken before and after the intervention revealed a time-by-group interaction, with positive average change in the EG and no reliable mean change in the ACG. Significant group differences in structural brain integrity changes were observed in the right and left ACC, right posterior cingulate cortex (PCC), and left juxtapositional lobule cortex (JLC). In all instances, average changes in the EG did not differ reliably from zero, whereas average changes in the ACG were negative, pointing to maintenance of structural brain integrity in the EG, and to losses in the ACG. Significant individual differences in change were observed for right ACC and left JLC. Following up on these differences, we found that exercising participants with greater fitness gains also showed more positive changes in structural integrity. We discuss the benefits and limitations of a latent-factor approach to changes in structural brain integrity, and conclude that aerobic fitness interventions are likely to contribute to brain maintenance in old age.

在老年人中，与无运动控制条件相比，有氧运动干预与前扣带皮层 (ACC) 和海马区等额叶和颞叶区域的积极或消极变化有关。然而，与基于多个指标的潜在构造相比，诸如灰质 (GM) 概率之类的单独测量可能提供的关于大脑结构完整性的维持或损失的可靠和有效的结论不太可靠和有效。在这里，我们根据体素形态测量、磁化转移饱和度和平均扩散率评估的 GM 概率，建立了 GM 结构完整性的潜在因素。基于这个潜在因素，我们调查了之前在使用体积方法的研究中报告的大脑区域的六个月运动干预期间大脑结构完整性的变化。75 名以前久坐的 63-76 岁健康的老年人在任一运动组（EG；n= 40) 或在积极的对照组 (ACG;n= 35)。峰值摄氧量（VO ₂干预前后的峰值）显示了逐组的交互作用，EG 的平均变化为正，而 ACG 的平均变化没有可靠的变化。在左右 ACC、右后扣带皮层 (PCC) 和左并列小叶皮层 (JLC) 中观察到结构性脑完整性变化的显着组间差异。在所有情况下，EG 的平均变化与零没有可靠的差异，而 ACG 的平均变化是负的，表明 EG 中的结构性大脑完整性得到维持，并且 ACG 中的损失。右侧 ACC 和左侧 JLC 的变化存在显着的个体差异。跟进这些差异，我们发现锻炼身体健康的参与者在结构完整性方面也表现出更积极的变化。