In addition, amyloidosis is a common pathological feature of AD and diabetes mellitus (de Matos et al., 2018), and the diagnostic accuracy of plasma Aβ1-42/1-40 combined with APP 669-711/Aβ1-42 was 90% for AD (Nakamura et al., 2018), but the potential association between plasma Aβ levels and cognitive functions has not been reported. Here, APP is linked to Alzheimer disease.