Poor Sleep & Dementia Risk

Dementia affects millions of people worldwide and currently has no cure. Alzheimer’s disease (AD) accounts for ~70% of dementia cases. Sleep may play an important role in AD risk. Experimental and epidemiological studies show that sleep is critical for memory consolidation and the clearance of toxic proteins that form amyloid plaques and tau tangles in the brain - both hallmark pathologies of AD. As such, sleep represents a promising target for dementia risk reduction and prevention. However, sleep is a highly complex physiological state that depends on precisely timed, coordinated, and uninterrupted patterns of sleep stages and neural activity working together to support optimal brain function. Consequently, sleep disturbance can manifest in many forms, affecting different characteristics of sleep physiology. Which aspects of disturbed sleep contribute to early AD pathogenesis, and how these relationships evolve over time, remain unclear. Our team leads the Brain and Cognitive Health (BACH) study, a prospective cohort investigating risk and protective factors for dementia. As part of BACH, comprehensive sleep assessment has been conducted in 240 midlife and older adults using polysomnography, actigraphy, and self-report measures. Participants have also undergone AD biomarker assessment, cognitive testing, and brain MRI. Four-year follow-up of the cohort is currently underway. Using these data the overarching aim of this study is to: Determine how poor sleep influences brain health and biomarkers of AD pathology in midlife and older adults. Findings from this work will help identify specific sleep targets for early intervention trials to reduce dementia risk or delay the onset of AD.