Characterizing Japanese older adults without dementia by amyloid PET status: A comparative study of amyloid‐positive and amyloid‐negative groups from Japanese trial‐ready cohort study

INTRODUCTION: This study aimed to identify demographic and cognitive differences based on amyloid status in older Japanese adults without dementia, addressing the lack of data in East Asian populations for early Alzheimer's disease (AD) detection. METHODS: Analyzed baseline data from 630 participants from the Japanese Trial-Ready Cohort (J-TRC) study, all with a Clinical Dementia Rating-Global Score (CDR-GS) of 0 or 0.5. Amyloid status (Aβ+ or Aβ-) was determined by amyloid positron emission tomography (PET) scans. RESULTS: Among participants, 24.8% were Aβ+. In the cognitively unimpaired (CDR-GS 0) group, Aβ+ individuals reported slightly greater self-perceived cognitive concerns (Cognitive Function Instrument [CFI-self]). For those with mild impairment (CDR-GS 0.5), Aβ+ status was associated with worse clinical scores, greater cognitive complaints, more depressive symptoms, and poorer memory and global cognition. DISCUSSION: These findings align with major Western studies, emphasizing that CFI-self is a valuable tool for identifying early AD pathology across diverse populations. Highlights: Comparing characteristics by amyloid status in Japanese non-demented older adults.Positron emission tomography-positive (PET+) scans in cognitively unimpaired individuals were associated with Cognitive Function Instrument-negative (CFI-) participants.PET+ in mild cognitive impairment (MCI) was linked to functional, cognitive, and affective decline.CFI- participants will aid early Alzheimer's pathology detection in diverse groups.