Department of Neurophysiology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
Department of Orthopaedic Surgery, The University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Cereb Cortex. 2023 Nov 27;33(23):11225-11234. doi: 10.1093/cercor/bhad358.
Insulin resistance may lead to structural and functional abnormalities of the human brain. However, the mechanism by which insulin resistance impairs the brain remains elusive. In this study, we used two large neuroimaging databases to investigate the brain regions where insulin resistance was associated with the gray matter volume and to examine the resting-state functional connectivity between these brain regions and each hypothalamic nucleus. Insulin resistance was associated with reduced gray matter volume in the regions of the default-mode and limbic networks in the cerebral cortex in older adults. Resting-state functional connectivity was prominent between these networks and the paraventricular nucleus of the hypothalamus, a hypothalamic interface connecting functionally with the cerebral cortex. Furthermore, we found a significant correlation in these networks between insulin resistance-related gray matter volume reduction and network paraventricular nucleus of the hypothalamus resting-state functional connectivity. These results suggest that insulin resistance-related gray matter volume reduction in the default-mode and limbic networks emerged through metabolic homeostasis mechanisms in the hypothalamus.
胰岛素抵抗可能导致人脑的结构和功能异常。然而，胰岛素抵抗损害大脑的机制仍不清楚。在这项研究中，我们使用了两个大型神经影像学数据库来研究与胰岛素抵抗相关的大脑区域与灰质体积的关系，并检查这些大脑区域与每个下丘脑核之间的静息状态功能连接。胰岛素抵抗与老年人大脑皮层默认模式和边缘网络区域的灰质体积减少有关。这些网络与下丘脑室旁核之间存在明显的静息状态功能连接，室旁核是连接大脑皮层的下丘脑界面。此外，我们在这些网络中发现了与胰岛素抵抗相关的灰质体积减少和网络室旁核静息状态功能连接之间的显著相关性。这些结果表明，通过下丘脑的代谢稳态机制，默认模式和边缘网络中与胰岛素抵抗相关的灰质体积减少。
