Don’t Ignore the Snore

April 3, 2024

Do you snore? It could be a sign of sleep apnea, a common sleep disorder that is tied to an increased risk of memory and thinking problems.

A large new study that looked at a nationally representative sample of American adults found that those who reported snoring or other symptoms of sleep apnea were about 50 percent more likely to report cognitive issues than their peers without sleep apnea symptoms. The findings add to growing evidence that sleep problems, including sleep apnea, raise the risk of developing Alzheimer’s disease or other forms of dementia years down the road.

Millions of older people, especially those who are overweight, have sleep apnea, though many don’t even know they have it. It occurs when the soft tissues at the back of the mouth and throat relax too much during sleep, causing the airways to become blocked. People with the condition often snore loudly and can wake up hundreds of times during the night, leading to daytime grogginess and fuzzy thinking, though they typically do not remember waking during the night.

Bed partners may notice that their partner experiences pauses in breathing for brief periods during the night. Other symptoms include snorting or gasping during the night, or morning headaches.

“Sleep apnea is a common disorder that is often underdiagnosed, yet treatments are available,” said study author Dr. Dominique Low of Boston Medical Center. “Our study found participants who had sleep apnea symptoms had greater odds of having memory or thinking problems.”

The study looked at 4,257 adults who ranged in age from 20 to over 80. Participants completed questionnaires covering sleep, memory, cognition, and decision-making abilities as part of the 2017-2018 National Health and Nutrition Examination Survey. Those who reported snorting, gasping, or breathing pauses during sleep were categorized as experiencing sleep apnea symptoms. Individuals who reported difficulty remembering, periods of confusion, difficulty concentrating, or decision-making problems were classified as having memory or cognitive symptoms.

About a quarter of the participants, or 1,079, had symptoms of sleep apnea. Among those with symptoms, about a third reported having memory or thinking problems; only 20 percent of those without sleep apnea symptoms had cognitive problems. These results were consistent even after age, gender, race, and education level were considered. The findings will be presented at the upcoming American Academy of Neurology 2024 Annual Meeting in Denver.

The results show only an association between sleep apnea symptoms and cognitive problems and cannot prove cause and effect. They also rely on self-reporting of brain function and not laboratory tests for thinking and memory skills. But other studies have found a similar correlation between sleep problems and memory impairments.

Waking up multiple times during the night may impair the brain’s ability to clear out toxic proteins, which scientists believe may raise the risk of Alzheimer’s disease. Spending less time in deep sleep may also impair the brain’s ability to consolidate memories. Another reason could be that apnea is associated with low blood oxygen levels, which would reduce oxygen supply to the brain.

“These findings highlight the importance of early screening for sleep apnea,” said Dr. Low. If you suspect that breathing problems during sleep may be contributing to memory and thinking problems, it is important to discuss this with your doctor. It may be appropriate to get a test for sleep apnea, which may involve wearing a nighttime monitor.

Effective treatments for sleep apnea include a continuous positive airway pressure, or CPAP, machine, which involves wearing a special mask that promotes effective breathing during sleep. Studies suggest that those with sleep apnea who use a CPAP machine are at lower risk of developing dementia. Mouth devices are also available to promote better breathing during sleep. Losing weight may also help to reduce symptoms of sleep apnea, though it can occur in people who are not overweight.

Effective treatment of sleep apnea may have additional benefits as well. In addition to causing daytime sleepiness and fatigue, sleep apnea has been linked to medical conditions like heart disease, high blood pressure and diabetes, all of which are also tied to an increased risk of dementia.

By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.

Source: Dominique Low: “Sleep Apnea Symptoms Are Associated with Memory and Cognitive Symptoms in a Nationally-representative Sample of U.S. Adults.” American Academy of Neurology 2024 Annual Meeting, April 17, 2024


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