Sleep fragmentation correlates with amyloid beta deposition at brain autopsy

INTRODUCTION: Poor sleep is a symptom and candidate risk factor for Alzheimer's disease (AD). We investigated whether objective and subjective longitudinal sleep measures correlated with AD pathology at brain autopsy. METHODS: = 81.72) underwent annual evaluation with actigraphy along with sleep questionnaires and cognitive assessment. Brain autopsy provided quantitative neuropathologic data. RESULTS: Objective sleep fragmentation was associated with higher amyloid density. This association was only observed among individuals with low AD neuropathologic change or no/mild cognitive impairment. Last-measured sleep fragmentation had a stronger association with amyloid density than did mean sleep fragmentation across the study. Poorer subjective sleep quality was paradoxically linked to lower AD-related neuropathologic burden. DISCUSSION: These findings provide histopathologic evidence linking objectively measured sleep fragmentation to cerebral amyloid deposition and suggest that sleep disruption may be most relevant during earlier stages of AD pathogenesis.