MINNEAPOLIS – Obstructive sleep apnea occurs when breathing is repeatedly interrupted during sleep. Research has shown that people with this sleep disorder are at increased risk of developing cognitive impairment and Alzheimer’s disease. Still, it’s treatable. A preliminary study published today, February 28, 2021, found that obstructive sleep apnea is common in people with cognitive impairment. The study will be presented at the 73rd annual meeting of the American Academy of Neurology, practically held April 17-22, 2021.
Cognitive impairments include memory and thinking problems that affect concentration, decision-making, and learning new things. The risk of cognitive impairment increases with age.
Better sleep is beneficial to the brain and can improve cognitive skills. However, in our study, we found that more than half of people with cognitive impairment had obstructive sleep apnea. We also found that those with the sleep disorder had lower scores on thinking and memory tests. Understanding how obstructive sleep apnea affects this population is important, as treatment has the potential to improve thinking and memory, and the general quality of life.
Study author Mark I. Boulos, MD, of the University of Toronto in Canada and a member of the American Academy of Neurology.
The study enrolled 67 people with an average age of 73 who had cognitive impairment. Participants completed questionnaires on sleep, cognition, and mood. They also took a 30-point rating to determine the level of their cognitive impairment. Questions included identifying the date and city they were in and repeating words to remember at the beginning of the test. The score in the test area ranges from zero to 30. A score of 26 or higher is considered normal, 18-25 means mild cognitive impairment, and 17 or less means moderate to severe cognitive impairment.
Participants were given sleep apnea tests at home to see if they had obstructive sleep apnea. The home test uses a monitor to track breathing patterns and oxygen levels while you sleep.
The researchers found that 52% of the study participants had obstructive sleep apnea. People with the sleep disorder were 60% more likely to score fewer points on the cognitive test than people without sleep apnea. People with the disorder had an average score of 20.5 compared to an average score of 23.6 for people without the sleep disorder. In addition, the researchers found that the severity of obstructive sleep apnea matched the participants’ level of cognitive impairment, as well as the quality of their sleep, including how long they slept, the rate at which they fell asleep, the efficiency of their sleep, and the frequency with which they woke up at night .
People with cognitive impairment should be screened for obstructive sleep apnea, as it can be treated with a continuous positive airway pressure (CPAP) machine that keeps the airway open at night. However, not everyone who tries CPAP chooses therapy regularly, and this can be more of a challenge for people with thinking and memory problems. Future research should be directed to determining ways of diagnosing and treating the disease that are efficient and easy to use in people with cognitive impairments.
Mark I. Boulos
One limitation of the study was that it used home sleep apnea tests rather than laboratory sleep studies to diagnose sleep apnea.
The study was funded by an Ontario Graduate Scholarship awarded to study author David R. Colelli and the LC Campbell Cognitive Neurology Research Unit at Sunnybrook Health Sciences Center in Toronto, Canada. ResMed provided the home sleep apnea tests in kind, but was not involved in the design of the study.
View press release