Night-to-night variability in sleep and amyloid beta burden in normal aging

Area of Science:

• Neuroscience
• Sleep Medicine
• Biomarker Discovery

Background:

• Alzheimer's disease is linked to sleep disturbances and amyloid-beta accumulation in the brain.
• Identifying early biomarkers is crucial for understanding and potentially intervening in Alzheimer's disease progression.

Purpose of the Study:

• To investigate if actigraphy-measured sleep parameters can serve as biomarkers for early cerebral amyloid burden.
• To correlate specific sleep disruption patterns with amyloid-positron emission tomography (PET) scan results.

Main Methods:

• Eighty-six participants underwent a week of actigraphy monitoring and an amyloid PET scan.
• Sleep duration and continuity (fragmentation, awakenings) were analyzed.
• Multiple linear regressions assessed the relationship between sleep parameter variability and amyloid burden.

Main Results:

• Amyloid-positive individuals exhibited greater variability in sleep fragmentation compared to amyloid-negative individuals.
• Increased sleep fragmentation variability correlated with higher amyloid burden in frontal, parietal regions, and precuneus.
• No significant differences were found in sleep duration between groups.

Conclusions:

• Variability in sleep continuity, particularly sleep fragmentation, shows potential as a biomarker for early amyloid pathogenesis in Alzheimer's disease.
• Actigraphy offers a non-invasive method to detect sleep alterations associated with preclinical Alzheimer's.