APOE and amyloid-tau pathology in cognitively unimpaired older adults

Abstract INTRODUCTION APOE genotype shows well-established dose-dependent associations with higher amyloid in cognitively unimpaired (CU) adults. In contrast, associations with tau burden and cognition are less well characterized. METHODS We performed a cross-sectional analysis of harmonized multi-cohort ADSP-PHC data from 4,380 CU participants across 4 cohorts with APOE genotype, amyloid PET, and cognitive data from four domains of memory, language, executive, and visuospatial function, including a subset of 758 with tau PET imaging. RESULTS APOE {varepsilon}4 showed a strong dose-dependent association with amyloid burden and amyloid positivity, with the highest levels observed among {varepsilon}4 homozygotes. Associations between APOE and global tau burden were more modest and appeared to be driven mainly by {varepsilon}4 homozygotes, while regional analyses showed localized APOE {varepsilon}4-related associations in medial temporal regions. Independently, higher tau burden was associated with lower memory and language performance. CONCLUSIONS In CU older adults, APOE {varepsilon}4 was most strongly associated with amyloid burden, with more modest associations observed for medial temporal tau burden.