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  • Writer's pictureKaren

Are you Getting Enough Sleep?

Updated: Jan 29, 2022

Lower and higher amounts of total sleep time are associated with reduced cognitive performance in older individuals

There may be a “sweet spot” in total sleep time for maintaining cognitive function during aging.


Poor sleep is associated with diminished cognitive performance, especially in older adults. Studies in older people have also linked shorter and longer sleep times to decreased cognitive function. Although detrimental changes in sleep patterns are thought to play a possible role in Alzheimer’s disease (AD), the relationship between sleep, cognitive function, and AD is not well understood. This study examined the connection between sleep patterns and changes in cognitive function over time in a cohort of older participants.

The study

To test the idea that sleep patterns are linked to a decline in cognitive function, sleep-wake activity was monitored in 100 community-living participants, in addition to AD biomarker analysis in the cerebrospinal fluid (CSF) and annual cognitive testing.

The participants were all enrolled in another longitudinal study on cognitive function that involved yearly cognitive testing. At the start of this trial, the participants underwent 4–6 nights of sleep monitoring using sleep logs, actigraphy, and EEG (electroencephalography, to monitor brain waves). The final annual test of cognitive function was performed 1 year after sleep monitoring.

AD biomarkers were also analyzed within 1 year of sleep monitoring by measuring AD biomarkers in CSF samples. The participants were also analyzed for APOE genotype (some variants in the APOE gene are associated with Alzheimer’s disease).