The cognitive function of people aged 45 and over is disrupted by chronic insomnia, regardless of the effect of other health problems associated with this sleep disorder that affects approximately 10% of the adult population.
Altered functions include the memory of facts, concepts, words and places.
This finding was established by Quebec researchers associated with the Universities of Montreal and Concordia following an analysis of sleep data from the pan-Canadian CLSA (Canadian Longitudinal Study on Aging) cohort of 28,485 participants from several Canadian cities, including Montreal.
Did you know?
- Chronic insomnia is when someone has difficulty falling asleep or staying asleep for at least three nights a week for more than three months, with impacts on how they function during the day such as changes in mood, attention and concentration.
- It must be distinguished from the mere presence of insomnia symptoms that have no impact on daytime functioning.
To date, several studies have shown links between insomnia and cognitive difficulties, but they were performed on a limited number of people, and the results were not always consistent.
In the present work, the participants belonged to three groups:
- Some had problems with chronic insomnia;
- Some had symptoms of insomnia without complaint of impact on daytime functioning;
- Some had normal sleep quality.
These included completing questionnaires and physical exams and a battery of neuropsychological tests, which were used to assess different cognitive functions and sleep quality.
“Chronic insomnia is often associated with many other disorders (eg, anxiety, chronic pain) that can also impact cognitive function, making it difficult to establish the direct contribution of insomnia to cognitive disorders.” says Dr. Dang-Vu, Chair of Research in Sleep, Neuroimaging and Cognitive Health at Concordia University and Professor in the Department of Neuroscience at the University of Montreal.
The purpose of our study was therefore to study precisely the link between chronic insomnia and cognitive function in a large sample of middle-aged and elderly people, taking into account the possible effect of these other disorders. health.
The big observations:
- People in the chronic insomnia group performed significantly worse on the tests than those in the other two groups.
- Declarative memory (memory based on concepts and facts, such as the meaning of words, places and historical events) is particularly affected.
Did you know?
- The recommended number of hours of sleep for adults is between seven and nine hours.
- One-third of Canadians aged 18 to 64 do not sleep the recommended number of hours.
- On average, Canadian adults aged 18 to 64 sleep 7.1 hours, but there is a difference between men (7 hours) and women (7.24 hours).
- Sleeping less than 7 hours a night alters the activity of circadian rhythm-associated biomarkers, such as hormones.
- In the long run, sleep-related problems are serious and include depression, memory problems, chronic stress, and obesity.
Researchers now want to better understand the relationship between poor sleep and cognitive disorders.
Does the presence of chronic insomnia predispose to cognitive decline? Are these cognitive deficits that are reversible with the treatment of sleep disorders?
According to the researchers, the best understanding of this relationship will have a major impact in the prevention and management of cognitive disorders linked to aging.
The details of this work are published in the journal Sleep).