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Change in sleep duration and cognitive function: findings from the Whitehall II Study
Jane E Ferrie1, Martin J Shipley, Tasnime N Akbaraly
1University College London, Department of Epidemiology and Public Health, London, UK. j.ferrie@ucl.ac.uk
Changes in sleep duration impact cognitive function in middle-aged adults. Both longer and shorter sleep times were linked to declines in reasoning and memory, equivalent to aging several years.
Area of Science:
- Neuroscience
- Sleep Science
- Cognitive Health
Background:
- Cross-sectional studies indicate a link between sleep and cognitive function.
- This research investigates how changes in sleep duration affect cognitive abilities over time.
Purpose of the Study:
- To determine if alterations in sleep duration predict cognitive function changes.
- To quantify the association between sleep duration changes and cognitive performance in middle-aged adults.
Main Methods:
- Prospective cohort study (Whitehall II) with 5431 participants (aged 45-69).
- Sleep duration assessed twice (1997-1999 and 2002-2004).
- Cognitive function measured using 6 tests including verbal memory, reasoning, and MMSE.
Main Results:
- Adverse sleep changes (decreases or increases in duration) were linked to lower scores on most cognitive tests.
- An increase from 7-8 hours or a decrease from 6-8 hours of sleep was associated with poorer cognitive function.
- These effects were comparable to 4-7 years of aging.
Conclusions:
- Changes in sleep duration are associated with declines in cognitive function among middle-aged individuals.
- Maintaining consistent sleep duration may be crucial for preserving cognitive health.
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