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A new study shows an association between sleep apnea symptoms and an increased risk of memory and thinking problems. Danil Nevsky/Stocksy
  • A new study analyzes the impact of sleep apnea symptoms on memory and thinking.
  • Sleep apnea is a sleep disorder that sometimes causes people to stop breathing.
  • The study subjects participated in a survey where they reported any symptoms of sleep apnea and difficulty with remembering things.
  • The study shows an association between sleep apnea symptoms and a higher rate of memory and thinking problems.

Getting a good night’s sleep is important for many reasons, from having the energy to go about one’s daily tasks to optimal brain performance.

Sleep apnea can interfere with this, and according to the National Council on Aging, it may impact around 39 million adults in the United States.

While experts know sleep apnea can impact quality of life and even contribute to mood disorders, there is still more to learn.

A researcher based in Boston recently conducted a cross-sectional study to determine whether a correlation between sleep apnea and thinking and memory problems exists.

The findings showed that having sleep apnea symptoms correlated with a 50% increase in memory and thinking problems.

The researcher will present the findings at the American Academy of Neurology’s Annual Meeting in April 2024. The research hasn’t yet been published in a peer-reviewed journal.

Most people with sleep apnea have obstructive sleep apnea (OSA), but some experts have said that OSA is underdiagnosed.

For instance, researchers note, “it is believed that more than 85% of patients with clinically significant OSA have never been diagnosed.”

With the notion that sleep apnea could be underdiagnosed in mind, researcher Dr. Dominique Low wanted to learn more about a possible connection between sleep apnea and cognition. Dr. Low works at Boston Medical Center in Massachusetts and is a member of the American Academy of Neurology.

Dr. Low pulled data from a government-funded survey called the 2017–18 National Health and Nutrition Examination Survey (NHANES) to establish a potential link between sleep apnea and thinking and memory.

The study participants included 4,257 adults ages 20 and older. Of the questionnaires they completed for the NHANES, they answered questions about sleep quality, memory, and thinking.

Dr. Low used the data from these questionnaires to determine how people who reported sleep apnea symptoms compared to people without these symptoms.

The participants also answered questions on their memory quality, whether they had any periods of confusion, and if the participants thought they had trouble making decisions.

A total of 1,079 participants reported sleep apnea symptoms, including snoring and gasping for breath while asleep.

Of people who indicated they had sleep apnea symptoms, 33% also reported symptoms of memory and thinking problems. This is significantly higher than the number of people without sleep apnea symptoms who reported such problems, which was only 20% of that group.

After adjusting for other factors like age, race, and gender, Dr. Low observed that people with sleep apnea symptoms had a 50% higher chance of having thinking and memory issues compared to participants who didn’t report sleep apnea symptoms.

“Our study found participants who had sleep apnea symptoms had greater odds of having memory or thinking problems,” Dr. Low said in a news release. “These findings highlight the importance of early screening for sleep apnea.”

Despite the implications of these findings, it’s important to note that a correlation does not indicate causation. Scientists must conduct further research that does not rely solely on self-reported symptoms to establish the effects of sleep apnea symptoms on memory and thinking.

Dr. Joey R. Gee, a neurologist at Providence Mission Hospital in Mission Viejo, California, spoke with Medical News Today about how sleep apnea may impact memory. Dr. Gee was not involved with the study.

“Apnea may have an impact due to poor oxygenation through the night or also impairing appropriate sleep cycles with frequent arousals,” Dr. Gee noted. “Impaired executive functions, such as working memory and attention through the day, are greatly impacted.”

Dr. Gee said that while untreated sleep apnea may impact cognitive function, the risk could be reduced with appropriate treatment.

“Just as untreated sleep apnea increases the risk of impairment in executive function and attention, treatment can substantially reduce the risk of progressing cognitive decline,” Dr. Gee said.

Dr. Thomas Kilkenny, the director of the Institute of Sleep Medicine at Staten Island University Hospital in New York, not involved in the study, emphasized the importance of treating sleep apnea as soon as it is detected.

“If the patient can be treated early in OSA, these brain damages will not occur,” Dr. Kilkenny told MNT. “There will be a decrease in the amount of cognitive decline in OSA patients.”

Dr. David Merrill, a geriatric psychiatrist and director of the Pacific Neuroscience Institute’s Pacific Brain Health Center at Providence Saint John’s Health Center in Santa Monica, California, not involved with the study, shared his thoughts on the findings with MNT:

“With high quality, restorative sleep, the brain’s function is enhanced and protected as we age,” explained Dr. Merrill. “If sleep is chronically disrupted, this can lead to a number of health issues, including headaches, fatigue, and memory loss that worsens over time. The disrupted, poor-quality sleep seen in sleep disorders leads to both acute and chronically worsening changes in the brain. Normally, a good night’s sleep literally allows for repair and restoration of brain function to the levels seen at the beginning of the prior day.”

Dr. Merrill also spoke about the importance of treating sleep apnea and noted that it is a risk factor for developing dementia. While that may sound scary, he said that using a CPAP machine can help reduce risk.

Research studies have shown that even 4 hours per night using a CPAP device results in significantly less worsening of cognitive decline over time,” said Dr. Merrill.

Sleep apnea, including obstructive sleep apnea and central sleep apnea, can affect people of all ages but, as the National Council on Aging notes (link above), it is most prevalent in middle-aged and older adults.

Some symptoms of sleep apnea a person may detect on their own include:

  • sleepiness during the day
  • headaches
  • difficulty focusing

A person’s partner may notice additional symptoms such as snoring or gasping for breath while asleep.

“Signs of obstructive sleep apnea are usually readily apparent,” Dr. Kilkenny said.

“Loud snoring, restlessness, and daytime fatigue are the hallmarks of OSA,” he noted. “If someone snores even to a minor degree, they should bring this to the attention of their physician so they can get tested for OSA before damage occurs.”

People with sleep apnea can treat it using a continuous positive airway pressure (CPAP) machine.

They may also try to improve symptoms by making lifestyle changes such as losing weight. They may also have surgery or use an oral appliance.