Association of Sleep and β-Amyloid Pathology Among Older Cognitively Unimpaired Adults

Key Points Question What is the magnitude and time of onset of the association between daytime and nighttime sleep with β-amyloid (Aβ) pathology in cognitively unimpaired older adults? Findings In this cross-sectional study of 4425 cognitively unimpaired participants, each additional hour of nighttime sleep was associated with a statistically significant reduction of Aβ positron emission tomographic standardized uptake value ratio, whereas daytime sleep was associated with increased regional accumulation of Aβ. The association occurs early, before significant Aβ accumulation or cognitive impairment, and in specific regions of the brain. Meaning If longer sleep duration leads to reduced amyloid levels, treatments increasing sleep duration may reduce Aβ accumulation and aid in delaying the onset of cognitive dysfunction associated with Aβ deposition.
Importance Disrupted sleep commonly occurs with progressing neurodegenerative disease. Large, well-characterized neuroimaging studies of cognitively unimpaired adults are warranted to clarify the magnitude and onset of the association between sleep and emerging β-amyloid (Aβ) pathology. Objective To evaluate the associations between daytime and nighttime sleep duration with regional Aβ pathology in older cognitively unimpaired adults. Design, Setting, and Participants In this cross-sectional study, screening data were collected between April 1, 2014, and December 31, 2017, from healthy, cognitively unimpaired adults 65 to 85 years of age who underwent florbetapir F 18 positron emission tomography (PET), had APOE genotype information, scored between 25 and 30 on the Mini-Mental State Examination, and had a Clinical Dementia Rating of 0 for the Anti-Amyloid Treatment in Asymptomatic Alzheimer Disease (A4) Study. Data analysis was performed from December 1, 2019, to May 10, 2021. Exposures Self-reported daytime and nighttime sleep duration. Main Outcomes and Measures Regional Aβ pathology, measured by florbetapir PET standardized uptake value ratio. Results Amyloid PET and sleep duration information was acquired on 4425 cognitively unimpaired participants (mean [SD] age, 71.3 [4.7] years; 2628 [59.4%] female; 1509 [34.1%] tested Aβ positive). Each additional hour of nighttime sleep was associated with a 0.005 reduction of global Aβ standardized uptake value ratio (F1, 4419 = 5.0; P = .03), a 0.009 reduction of medial orbitofrontal Aβ (F1, 4419 = 17.4; P
This cross-sectional study evaluates the associations between daytime and nighttime sleep duration with regional β-amyloid pathology in older cognitively unimpaired adults.