NOV 03, 2021 7:09 PM PDT

The Right Amount of Sleep for Stable Cognition in Older Adults

WRITTEN BY: Alexandria Bass

The wonders of sleep. What a good night's sleep can do for our resistance to stress, memory, and creative insight. Some famous discoveries are even said to have come in dreams – the Scientific Method supposedly came to Rene Descartes in a dream. But as we age and our sleep requirements change, is there a certain amount of sleep, a so-called sleep sweet spot, that allows our brains to work more efficiently and stave off cognitive decline? 

Researchers from the Knight Alzheimer Disease Research Center at Washington University published a new study in the journal Brain investigating the link between sleep duration and cognitive functioning to determine if sleep could be a potential marker for Alzheimer's disease progression. The study's lead researcher, Brendan Lucey, MD, MSCI, had found in earlier investigations that poor sleep quality was associated with early signs of Alzheimer's. 

This current study, a longitudinal study of 100 older adults, examined participants' sleep-wake activity over 4 to 6 nights with an EEG device. Participants completed annual cognitive testing for obtaining the Preclinical Alzheimer Cognitive Composite (PACC) score, and Alzheimer's disease markers – tau and amyloid-B42 – were measured in each participant's cerebrospinal fluid (CSF). Most participants had a clinical dementia rating of 0 at baseline, meaning they had no cognitive impairments. CSF results correlated with dementia ratings from testing.

Study results showed that older adults who slept between 4.5 and 6.5 hours a night had more stable cognitive function over time, while those who slept less than 4.5 hours or greater than 6.5 hours experienced significant cognitive decline over time, even when accounting for confounders of age, years of education, sex, and APOE genotypes (some APOE gene variants are associated with an increased risk of Alzheimer's disease).

With more details uncovered on the relationship between sleep and cognition, researchers hope study results can be used clinically when providers make recommendations to their older patients on sleep guidelines for maintaining optimal cognitive functioning.
 

About the Author
  • Alexandria (Alex) is a freelance science writer with a passion for educating the public on health issues. Her other professional experience includes working as a speech-language pathologist in health care, a research assistant in a food science laboratory, and an English teaching assistant in Spain. In her spare time, Alex enjoys cycling, lap swimming, jogging, and reading.
You May Also Like
DEC 16, 2021
Health & Medicine
Could Stem Cells Cure Type 1 Diabetes?
DEC 16, 2021
Could Stem Cells Cure Type 1 Diabetes?
For people living with chronic diseases like Type 1 diabetes, the word "cure" sounds too good to be true. In f ...
DEC 22, 2021
Health & Medicine
How the Internet Affects How Smart We Think We Are
DEC 22, 2021
How the Internet Affects How Smart We Think We Are
New research from the University of Texas at Austin on the interface between humans and Google shows Google can give us ...
DEC 24, 2021
Coronavirus
COVID-19 Tests & What to do About a Positive Result
DEC 24, 2021
COVID-19 Tests & What to do About a Positive Result
There are several types of tests for COVID-19. A laboratory test for SARS-CoV-2 (the virus that causes COVID-19) will te ...
JAN 11, 2022
Drug Discovery & Development
The FDA grants approval for a new insomnia drug to improve sleep in adults
JAN 11, 2022
The FDA grants approval for a new insomnia drug to improve sleep in adults
The Swiss biotech company Idorsia announced this week that it has received approval from the United States Foo ...
JAN 14, 2022
Technology
Do People Trust Artificial Intelligence?
JAN 14, 2022
Do People Trust Artificial Intelligence?
What exactly is artificial intelligence (AI)?  It may sound like science fiction, and often conjures up images of m ...
JAN 13, 2022
Microbiology
Dengue Virus Makes Mosquitoes Bite More Frequently
JAN 13, 2022
Dengue Virus Makes Mosquitoes Bite More Frequently
There are parasites that can change the behavior of their hosts to make a more beneficial outcome for the parasite. Rese ...
Loading Comments...