GPT and Alzheimer disease: Similarly, a recent cohort study revealed that decreased liver functions, including lower levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), were associated with AD diagnosis, impaired memory, and executive function, as well as cerebrospinal fluid biomarkers of AD, such as Aβ42 and p-Tau181 (Nho et al., 2019).