Longitudinal association between sleep and Alzheimer's pathology.

Area of Science:

• Neuroscience
• Gerontology
• Sleep Medicine

Background:

• Sleep disturbance is a modifiable risk factor for Alzheimer's disease (AD).
• Associations between sleep and AD pathology in cognitively unimpaired (CU) individuals remain under investigation.

Purpose of the Study:

• To test associations between objective sleep measures and AD pathology in CU individuals.
• To investigate both cross-sectional and longitudinal relationships between sleep variability and AD biomarkers.

Main Methods:

• Utilized data from 223 participants in the PREVENT-AD cohort.
• Employed self-reported sleep measures, objective actigraphy, and positron emission tomography (PET) scans for AD pathology quantification.
• Conducted robust linear models (RLMs) for cross-sectional and longitudinal analyses over a mean follow-up of 4.31 years.

Main Results:

• Actigraphy-based sleep variability (duration, efficiency, fragmentation) was associated with tau burden.
• Increased variability in sleep fragmentation correlated with amyloid burden.
• Variability in sleep efficiency predicted amyloid burden and its faster accumulation over time.

Conclusions:

• Irregularity in sleep patterns is significantly associated with higher AD pathological burden.
• Sleep pattern irregularity may indicate accelerated amyloid accumulation, suggesting a potential early marker for AD progression.