Introduction: Alzheimer's disease is associated with sleep disturbances and accumulation of cerebral amyloid beta. The objective was to examine whether actigraphy-detected sleep parameters might be biomarkers for early amyloid burden.
Methods: Participants underwent a week of actigraphy and an amyloid positron emission tomography (PET) scan. Sleep duration and continuity disruption (sleep fragmentation and nocturnal awakenings) were extracted and compared between amyloid-positive and amyloid-negative participants. Then multiple linear regressions were used between mean or night-to-night intra-individual variability (standard deviation) of sleep parameters and brain amyloid burden in a voxel-wise analysis.
Results: Eighty-six subjects were included (80.3 ± 5.4 years; 48.8% of women). Amyloid-positive participants had a higher variability of sleep fragmentation compared to amyloid-negative participants. This parameter was associated with a higher amyloid burden in the frontal and parietal regions, and in the precuneus, in the whole sample.
Discussion: This study highlights the relevance of using variability in sleep continuity as a potential biomarker of early amyloid pathogenesis.
Keywords: PET; actigraphy; aging; amyloid; intra‐individual variability of sleep; sleep.
© 2023 The Authors. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals LLC on behalf of Alzheimer's Association.