Prolonged morning wake transitions associated with amyloid beta burden: A cross-sectional pilot study.

INTRODUCTION: Sleep quality critically influences amyloid beta (Aβ) clearance, yet the specific role of morning wake transition duration remains unexplored. METHODS: This hypothesis-driven secondary analysis examined 97 cognitively unimpaired older adults (mean age ± SD: 74.4 ± 5.8 years) who underwent 14-day actigraphy and 18F-florbetapir positron emission tomography (PET). Cognitive function was evaluated using the National Center for Geriatrics and Gerontology-Functional Assessment Tool (NCGG-FAT). Time to wake up (TWU) was calculated as the midpoint between initial wake and final rise times. RESULTS: Binomial logistic regression models adjusted for age, depression, and sleep duration showed that extended TWU (>6.23 min) associated with higher Aβ positivity (27.1% vs 10.2%, odds ratio [OR] = 1.85, 95% confidence interval [CI]: 1.11-3.07, p = 0.019) and impaired word memory (OR = 2.17, 95% CI: 1.11-4.24, p = 0.023). Exploratory analyses of additional cognitive domains showed no significant associations. DISCUSSION: Prolonged morning wake transitions may represent a behavioral marker associated with Aβ accumulation and memory impairment. The cross-sectional design and modest sample size warrant cautious interpretation and replication in larger longitudinal cohorts.