INS and type 2 diabetes mellitus: Several studies have revealed shared common pathogenic mechanisms between AD and type 2 diabetes (such as insulin signaling and glucose metabolism impairment, inflammatory pathways, and neuronal stress signaling), which lead to neurodegeneration, memory deficits, and cognitive decline (Gm and Sa, 2007; de la Monte, 2017; Ferreira D. et al., 2018; Mnn et al., 2018; Rad et al., 2018; Wijesekara et al., 2018; Hölscher, 2019).