Insulin Resistance-related Gray Matter Volume Reduction is Associated with the Default Mode Network.

In this study, we observed that insulin resistance is linked to a reduction in grey matter volume in the default-mode and limbic networks of the cerebral cortex in older adults. Additionally, we found that the paraventricular nucleus of the hypothalamus is significantly functionally connected to these two cortical networks. Our results suggest that the reduction in gray matter volume associated with insulin resistance arises through metabolic homeostasis mechanisms in the hypothalamus.