Type I is a diabetes-related insulin deficiency and can occur in the brain of AD patients, while type II is a diabetes-related insulin resistance and other diabetes-related indicator abnormalities, such as abnormal end-glycosylation products and insulin-degrading enzyme abnormalities (Yamagishi et al., 2005; Lester-Coll et al., 2006; Frisardi et al., 2010; Jolivalt et al., 2010; Kochkina et al., 2015). Here, IDE is linked to diabetes mellitus.