As another person commented, we currently believe the primary mechanism behind the pleitropic effects of GLP-1's to be a reduction in systemic inflammation and direct improvements in vascular/endothelial function.

The best paper I've seen on this was the recently published and very aptly named:

"Pleiotropic effects of GLP-1 receptor agonists — a narrative review of extra-metabolic outcomes in adults" (2026)

https://journals.viamedica.pl/medical_research_journal/artic...