Summary: New research shows that reduced time in slow wave and REM sleep is associated with smaller brain volumes in regions vulnerable to Alzheimer’s disease. Using sleep studies and brain imaging data from 270 participants, researchers found that poor sleep architecture was linked to brain atrophy over time—particularly in the inferior parietal region, an area affected early in Alzheimer’s.
These associations held even after accounting for factors like age, heart health, and lifestyle habits. The findings suggest that disrupted sleep may be a modifiable risk factor for Alzheimer’s and highlight the importance of restorative sleep for long-term brain health.
Key Facts:
- Sleep-Related Brain Shrinkage: Less REM and slow wave sleep linked to smaller brain volumes.
- Alzheimer’s Risk Areas Affected: Inferior parietal region showed the strongest impact.
- Modifiable Risk Factor: Sleep quality could influence Alzheimer’s disease progression.
Source: AASM
New research reveals that lower proportions of specific sleep stages are associated with reduced brain volume in regions vulnerable to the development of Alzheimer’s disease over time.
Results show that individuals with lower proportions of time spent in slow wave sleep and rapid eye movement sleep had smaller volumes in critical brain regions, particularly the inferior parietal region, which is known to undergo early structural changes in Alzheimer’s disease.
The results were adjusted for potential confounders including demographic characteristics, smoking history, alcohol use, hypertension, and coronary heart disease.
“Our findings provide preliminary evidence that reduced neuroactivity during sleep may contribute to brain atrophy, thereby potentially increasing the risk of Alzheimer’s disease,” said lead author Gawon Cho, who has a doctorate in public health and is a postdoctoral associate at Yale School of Medicine in New Haven, Connecticut.
“These results are particularly significant because they help characterize how sleep deficiency, a prevalent disturbance among middle-aged and older adults, may relate to Alzheimer’s disease pathogenesis and cognitive impairment.”
The study was published March 31 as an accepted paper in the Journal of Clinical Sleep Medicine, the official publication of the American Academy of Sleep Medicine.
According to the Alzheimer’s Association, Alzheimer’s disease is a degenerative brain disease and the most common cause of dementia. An estimated 6.7 million Americans aged 65 and older are living with Alzheimer’s disease, and this number is projected to double by 2060, pending medical developments to prevent, slow or cure the disease.
The study involved an analysis of data from 270 participants who had a median age of 61 years. Fifty-three percent were female, and all participants were white. Individuals were excluded from the analysis if they previously had a stroke or probable dementia or other significant brain pathology.
The research utilized polysomnography to assess baseline sleep architecture. Advanced brain imaging techniques were used to measure brain volumes 13 to 17 years later.
According to the authors, the study demonstrates an important association between sleep and long-term brain health, and it highlights potential opportunities to reduce the risk of Alzheimer’s disease.
“Sleep architecture may be a modifiable risk factor for Alzheimer’s disease and related dementias, posing the opportunity to explore interventions to reduce risk or delay Alzheimer’s onset,” said Cho.
The researchers emphasized that further investigation is needed to fully understand the causal relationships between sleep architecture and Alzheimer’s disease progression.
About this sleep and Alzheimer’s disease research news
Author: Thomas Heffron
Source: AASM
Contact: Thomas Heffron – AASM
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Lower slow wave sleep and rapid eye movement sleep are associated with brain atrophy of AD-vulnerable regions” by Gawon Cho et al. Journal of Clinical Sleep Medicine
Abstract
Lower slow wave sleep and rapid eye movement sleep are associated with brain atrophy of AD-vulnerable regions
Study Objectives:
Sleep deficiency is associated with Alzheimer’s disease (AD) pathogenesis. We examined the association of sleep architecture with anatomical features observed in AD: (1) atrophy of hippocampus, entorhinal, inferior parietal, parahippocampal, precuneus, and cuneus regions (“AD-vulnerable regions”) and (2) cerebral microbleeds.
Methods:
In 270 participants of the Atherosclerosis Risk in the Communities Study, we examined the association of baseline sleep architecture with anatomical features identified on brain MRI 13∼17 years later.
Sleep architecture was quantified as the proportion of slow wave sleep (SWS), proportion of rapid eye movement (REM) sleep, and arousals index using polysomnography.
Outcomes included (1) volumetric measurements of each AD-vulnerable region and (2) the presence of any cerebral microbleeds (CMBs) and that of lobar CMBs, which are more specifically associated with AD. We analyzed the association of each sleep predictor with each MRI outcome, adjusting for covariates.
Results:
Median age was 61, 53% female, 100% were White, and 47% had 16+ years of education. Mmedian times in SWS and REM were 17.4% and 21.5%, respectively. Having less SWS was associated with smaller volumes of the inferior parietal region (β=-44.18 mm3 per -1 percentage point [PP] of SWS, [95%CI=-76.62, -11.74]) and cuneus (β=-11.98 [=-20.92, -3.04] mm3 per -1 PP of SWS).
Having less REM was associated with smaller volumes of the inferior parietal region (β=-75.54 [-129.36, -21.72] mm3 per 1 PP of REM) and precuneus (β=-31.92 [-63.78,-0.06] mm3 per 1 PP of REM).
After FDR adjustments, lower SWS and REM were associated with significantly smaller inferior parietal region volumes. Arousal index was not associated with the volumes of AD-vulnerable regions. None of the sleep architecture variables were associated with CMBs or lobar CMBs.
Conclusions:
Sleep deficiency is associated with the atrophy of the inferior parietal region, which is observed in early AD. Sleep architecture may be a modifiable risk factor for AD.
