Greater REM sleep percentage was associated with a more favorable plasma amyloid profile, suggesting that REM sleep architecture measured using ambulatory EEG may be particularly sensitive to amyloid-related changes prior to dementia.
Greater REM sleep percentage was significantly associated with lower plasma Aβ40 levels in older adults without dementia.
Greater REM sleep percentage was significantly associated with a higher Aβ42/40 ratio, indicating a more favorable amyloid profile.
Higher Pittsburgh Sleep Quality Index (PSQI) scores were nominally associated with higher plasma Aβ42 levels, but this did not survive false discovery rate correction.
Higher PSQI scores were nominally associated with higher plasma neurofilament light (NfL) levels, a marker of neurodegeneration, but the association did not survive false discovery rate correction.
The study sample consisted of sedentary community-dwelling older adults with insomnia symptoms but without dementia, with a mean age of 70.0 ± 6.0 years and 80.6% female.
Actigraphy-measured sleep parameters were not significantly associated with any plasma ATN biomarkers after correction.
This research suggests that the amount of REM (rapid eye movement) sleep a person gets is linked to Alzheimer's disease-related proteins in the blood, even before any signs of dementia appear. Specifically, older adults who had more REM sleep showed lower levels of a form of amyloid protein (Aβ40) and a more favorable ratio of amyloid proteins (Aβ42/40) — patterns associated with healthier brain status. These findings came from a study of 103 community-dwelling older adults who had insomnia symptoms but no dementia, with a subgroup of 56 people undergoing detailed brain wave monitoring during sleep. The study also found suggestive — though not statistically definitive — links between poorer self-reported sleep quality and higher levels of amyloid and neurofilament light proteins in the blood, both of which are markers associated with Alzheimer's disease risk. However, these associations were not strong enough to hold up after accounting for the possibility of chance findings across multiple tests, so they should be interpreted cautiously. This research suggests that measuring sleep using brain wave technology (EEG) may be a more sensitive tool than wrist-worn activity monitors or self-reported sleep questionnaires for detecting early Alzheimer's-related brain changes in people who do not yet have dementia. The findings highlight REM sleep in particular as potentially important to brain health in aging, though larger studies are needed to confirm these results and determine whether improving REM sleep could meaningfully reduce Alzheimer's disease risk.
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Upload Your LabsLiu S, Huang J, Calderon R, Spira A, Mcphillips M, Gooneratne N, et al.. (2026). Sleep architecture and self-reported sleep quality are associated with Alzheimer's disease biomarkers in older adults without dementia.. The journals of gerontology. Series A, Biological sciences and medical sciences. https://doi.org/10.1093/gerona/glag081