Changes in Nighttime Sleep Duration and Their Association With Cognitive Decline and Dementia Risk
Overton, Marieclaire LU ; Elmståhl, Sölve LU and Basna, Rani LU
(2026)
In Journal of Sleep Research
p.1-12
- Abstract
This study investigates changes in nighttime sleep duration in relation to cognitive decline and risk of incident dementia. A total of 3057 participants from the Swedish population study ‘Good Aging in Skåne’ (Mage = 68.4) with normal baseline sleep duration (6–8 h) were followed up to 20 years (Myears = 8.39). Self-reported change was defined as shortened or prolonged if participants lost or gained more than 1 h since their previous visit and sleep variability was defined as the SD of sleep duration across visits. Cognitive decline was assessed using an aggregated measure of global cognition. Linear mixed effects models examined the rate of decline across sleep change groups, adjusting for health-related factors,... (More)
This study investigates changes in nighttime sleep duration in relation to cognitive decline and risk of incident dementia. A total of 3057 participants from the Swedish population study ‘Good Aging in Skåne’ (Mage = 68.4) with normal baseline sleep duration (6–8 h) were followed up to 20 years (Myears = 8.39). Self-reported change was defined as shortened or prolonged if participants lost or gained more than 1 h since their previous visit and sleep variability was defined as the SD of sleep duration across visits. Cognitive decline was assessed using an aggregated measure of global cognition. Linear mixed effects models examined the rate of decline across sleep change groups, adjusting for health-related factors, including time spent in bed without sleeping. Cox proportional hazard models estimated dementia risk. Longitudinal patterns of prolonged sleep (> 1 h increase) were associated with significant cognitive decline in fully adjusted models. Greater sleep variability was also associated with steeper cognitive decline. There was a 131% increased risk of dementia (HR = 2.31, 95% CI: I 1.77–3.03; p < 0.001) for prolonged sleep in comparison to stable sleep. Higher sleep variability was also associated with increased dementia risk (HR = 1.49, 95% CI: 1.70–1.89; p < 0.001). Shortened sleep was not found to be significantly associated with cognitive decline or dementia risk. These findings indicate that changes in sleep duration, particularly prolonged sleep and high variability, are associated with faster cognitive decline and incident dementia, and may serve as markers of future cognitive impairment.
(Less)
- author
- Overton, Marieclaire
LU
; Elmståhl, Sölve
LU
and Basna, Rani
LU
- organization
- publishing date
- 2026
- type
- Contribution to journal
- publication status
- epub
- subject
- keywords
- cognitive decline, dementia, prolonged sleep, sleep duration changes, time in bed
- in
- Journal of Sleep Research
- article number
- e70414
- pages
- 1 - 12
- publisher
- Wiley-Blackwell
- external identifiers
-
- scopus:105046066364
- pmid:42522237
- ISSN
- 0962-1105
- DOI
- 10.1111/jsr.70414
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2026 The Author(s). Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.
- id
- 134fba24-bba8-475e-ae1d-96af540f3127
- date added to LUP
- 2026-08-20 08:59:55
- date last changed
- 2026-09-17 10:44:40
@article{134fba24-bba8-475e-ae1d-96af540f3127,
abstract = {{<p>This study investigates changes in nighttime sleep duration in relation to cognitive decline and risk of incident dementia. A total of 3057 participants from the Swedish population study ‘Good Aging in Skåne’ (M<sub>age</sub> = 68.4) with normal baseline sleep duration (6–8 h) were followed up to 20 years (M<sub>years</sub> = 8.39). Self-reported change was defined as shortened or prolonged if participants lost or gained more than 1 h since their previous visit and sleep variability was defined as the SD of sleep duration across visits. Cognitive decline was assessed using an aggregated measure of global cognition. Linear mixed effects models examined the rate of decline across sleep change groups, adjusting for health-related factors, including time spent in bed without sleeping. Cox proportional hazard models estimated dementia risk. Longitudinal patterns of prolonged sleep (> 1 h increase) were associated with significant cognitive decline in fully adjusted models. Greater sleep variability was also associated with steeper cognitive decline. There was a 131% increased risk of dementia (HR = 2.31, 95% CI: I 1.77–3.03; p < 0.001) for prolonged sleep in comparison to stable sleep. Higher sleep variability was also associated with increased dementia risk (HR = 1.49, 95% CI: 1.70–1.89; p < 0.001). Shortened sleep was not found to be significantly associated with cognitive decline or dementia risk. These findings indicate that changes in sleep duration, particularly prolonged sleep and high variability, are associated with faster cognitive decline and incident dementia, and may serve as markers of future cognitive impairment.</p>}},
author = {{Overton, Marieclaire and Elmståhl, Sölve and Basna, Rani}},
issn = {{0962-1105}},
keywords = {{cognitive decline; dementia; prolonged sleep; sleep duration changes; time in bed}},
language = {{eng}},
pages = {{1--12}},
publisher = {{Wiley-Blackwell}},
series = {{Journal of Sleep Research}},
title = {{Changes in Nighttime Sleep Duration and Their Association With Cognitive Decline and Dementia Risk}},
url = {{http://dx.doi.org/10.1111/jsr.70414}},
doi = {{10.1111/jsr.70414}},
year = {{2026}},
}