School of Artificial Intelligence, Beijing Normal University, Beijing 100875, P.R. China.
State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, P.R. China.
Cereb Cortex. 2023 Mar 10;33(6):2901-2911. doi: 10.1093/cercor/bhac248.
Understanding the characteristics of intrinsic connectivity networks (ICNs) in terms of both glucose metabolism and functional connectivity (FC) is important for revealing cognitive aging and neurodegeneration, but the relationships between these two aspects during aging has not been well established in older adults.
This study is to assess the relationship between age-related glucose metabolism and FC in key ICNs, and their direct or indirect effects on cognitive deficits in older adults.
We estimated the individual-level standard uptake value ratio (SUVr) and FC of eleven ICNs in 59 cognitively unimpaired older adults, then analyzed the associations of SUVr and FC of each ICN and their relationships with cognitive performance.
The results showed both the SUVr and FC in the posterior default mode network (pDMN) had a significant decline with age, and the association between them was also significant. Moreover, both decline of metabolism and FC in the pDMN were significantly correlated with executive function decline. Finally, mediation analysis revealed the glucose metabolism mediated the FC decline with age and FC mediated the executive function deficits.
Our findings indicated that covariance between glucose metabolism and FC in the pDMN is one of the main routes that contributes to age-related executive function decline.
理解葡萄糖代谢和功能连接（FC）内在连接网络（ICNs）的特征对于揭示认知老化和神经退行性变很重要，但在老年人中，这两个方面之间的关系尚未得到很好的建立。
本研究旨在评估关键 ICNs 中与年龄相关的葡萄糖代谢和 FC 之间的关系，以及它们对老年人认知缺陷的直接或间接影响。
我们估计了 59 名认知正常的老年人中 11 个 ICN 的个体水平标准摄取值比（SUVr）和 FC，然后分析了每个 ICN 的 SUVr 和 FC 的相关性及其与认知表现的关系。
结果表明，后默认模式网络（pDMN）的 SUVr 和 FC 都随年龄显著下降，它们之间的相关性也很显著。此外，pDMN 中代谢和 FC 的下降都与执行功能的下降显著相关。最后，中介分析显示葡萄糖代谢介导了 pDMN 中年龄相关的 FC 下降，而 FC 介导了执行功能缺陷。
我们的研究结果表明，pDMN 中葡萄糖代谢和 FC 之间的协方差是导致与年龄相关的执行功能下降的主要途径之一。
