The cognitive impairment of T2DM has a similar neuropathological basis as AD (Bedse et al., 2015), and the chronic hyperglycemia would accelerate the accumulation of β-amyloid and tau tangles, which promote neurodegeneration, resulting in the functional brain network damage and varying degrees of cognitive impairment (Verdile et al., 2015; Gibas, 2017). This evidence concerns the gene MAPT and Cognitive impairment.