Longitudinal association between sleep and Alzheimer's pathology

Since sleep disturbance is a modifiable risk factor for Alzheimer's disease (AD), we tested associations between sleep and AD pathology in cognitively unimpaired (CU) persons.

We included 223 participants from the PREVENT-AD cohort with self-reported measures of sleep, objective actigraphy measures of sleep, and positron emission tomography (PET) scans for AD pathology quantification. Repeated PET scans (mean follow-up: 4.31 ± 0.55 years) were available for 103 participants. We conducted robust linear models (RLM) for cross-sectional analyses and RLMs using the annual change in AD pathology for longitudinal analyses.

All actigraphy-based sleep variability measures were associated with tau burden (duration: β = 0.121 [95% confidence interval {CI} = 0.010; 0.232], p = 0.034; efficiency: 0.122 [0.010; 0.235], 0.033; fragmentation: 0.115 [0.010; 0.221], 0.033). Greater variability in sleep fragmentation was also associated with amyloid burden (0.074 [0.008; 0.140], 0.028), and variability in sleep efficiency portended amyloid burden and faster accumulation over time (0.075 [0.009; 0.141], 0.026; 0.164 [0.008; 0.320], 0.039; respectively).

Irregularity in sleep patterns is associated with higher pathological burden and faster amyloid accumulation.