Peripheral insulin resistance in T2DM leads to neuroinflammation and impairment of central insulin and IGF-1 signaling as well as metabolic dysfunction, mitochondrial dysfunction, and miRNA deregulation [94], thereby driving neurodegeneration and establishing a strong pathophysiological link between T2DM and AD [82,95] (Figure 1). Here, IGF1 is linked to type 2 diabetes mellitus.