Like T2DM, which is characterized by a decreased ability of peripheral tissues to metabolize glucose, in LOAD the decreased ability of brain to metabolize glucose (brain glucose hypometabolism) could contribute to the neurodegenerative process, together with the classical neuropathological LOAD hallmarks, such as Aβ deposits and hyperphosphorylated tau (p-tau) in neurofibrillary tangles (NFTs) [19,20]. This evidence concerns the gene MAPT and type 2 diabetes mellitus.