Most people with untreated sleep apnea develop heart disease, and researchers hypothesize that they also have cognitive problems. But a small new study suggests that obstructive sleep apnea itself is damaging the brain, prompting renewed urgency to recognize and treat the disorder.
Otherwise healthy middle-aged men newly diagnosed with obstructive sleep apnea showed poorer mental functioning in areas such as judgment, emotion regulation and recognizing other people’s feelings than men without the condition, according to research published Thursday in Frontiers in Sleep.
Obstructive sleep apnea, the most common form, when the throat muscles relax and the airway closes. Another type is central sleep apnea, which occurs when the brain does not send the correct signals to the muscles that control breathing. In both types, people wake up briefly in need of oxygen.
For the new study, researchers recruited 27 men between the ages of 35 and 70 who were not overweight and had a new diagnosis of mild to severe obstructive sleep apnea. Seven men of similar age, body weight, and education who did not have sleep apnea were also included. Both groups took a series of tests. Men who had obstructive sleep apnea showed cognitive deficits that increased with increasing severity.
As much as it is assumed 26% of adults in the US According to the American Academy of Sleep Medicine, people between the ages of 30 and 70 have sleep apnea. That may be an underestimate, as the condition is widely underdiagnosed, experts say. It is generally thought to affect men more than women.
Sleep apnea has been linked to memory and thinking problems, but new research shows that cognition is affected even if men don’t have an underlying health condition, emphasizing how important it is to get treatment early, said a senior co-author, Dr. Ivana Rosenzweig, a neuropsychiatrist who heads the Sleep and Brain Plasticity Center at King’s College London, said in an email.
“Our patients were mostly unaware of their cognitive deficits,” Rosenzweig said, adding that participants would not have sought help “unless their partners were snoring and bothering them.”
The new study is small, and Rosenzweig wants researchers to conduct larger studies that include women.
Until menopause, women are much less likely to have sleep disorders; However, its prevalence increases dramatically in women with age and weight, Rosenzweig said.
“It becomes almost equal between the sexes after menopause,” she said.
What causes sleep apnea?
It is not clear why obstructive sleep apnea causes cognitive deficits, although scientists suspect that frequent, however brief, awakenings lead to fragmented sleep and temporarily lower blood oxygen levels when breathing stops briefly.
Risk factors for obstructive sleep apnea include:
People often don’t know they have sleep apnea, Rosenzweig says. They usually seek help only when their partners tell them about problems like snoring.
“There can be cues like morning headaches or daytime drowsiness and fatigue,” he said.
Sleep apnea can be worse for health than insomnia because it can make it harder for the brain to fall into deep sleep, says Dr. Joel Salinas, a behavioral neurologist and researcher at NYU Langone Health and chief medical officer at Isaacs Health in New York. .
Cycle through the brain Different stages during sleepLight and deep sleep and rapid eye movement, or REM, sleep, which occurs during dreaming.
Deep sleep, also known as stage 3 sleep, is when memories are stored and the brain clears proteins that can cause damage over time, said Salinas, who was not involved in the new study.
“People with obstructive sleep apnea don’t spend much time in stage 3, instead waking up in stage 2 and going back to stage 1,” he said.
“Over time these people seem to have a higher accumulation of proteins, such as amyloid, that can increase the risk of cognitive impairment or dementia,” Salinas said.
Sleep apnea treatment
Doctors use many techniques Sleep apnea treatment, said Dr. Andrew Varg, a neuroscientist and physician at the Mount Sinai Integrative Sleep Center and associate professor of medicine at the Icahn School of Medicine at Mount Sinai in New York. Varga was not involved in the new study.
The most common is the continuous positive airway pressure, or CPAP, machine, which keeps the airway open during sleep.
There are also mandibular advancement devices that hold the lower jaw forward to keep the airway open. “They’re the second most popular method,” says Varga.
There are also operations to change the structure of the throat. They can be minimally invasive, like removing the uvula, the fleshy structure hanging above the throat, and some of the soft palate, the muscular part of the roof of the mouth, Varga says.
Some patients rely on implantable pacemaker-like devices that tell the nerves of the tongue to push it forward. On the more invasive end of the spectrum, a surgery is performed to reconstruct the jaw. “The jaw is broken on both sides and then pulled forward,” Varga said.
Brain studies have shown reduced activity in areas similar to what is seen in people Neurodegenerative diseases, Salinas said. That’s why it’s important to treat this type of sleep apnea early, he adds.
Lifestyle changes are a good place to start, he says.
“It’s always important to address potentially reversible issues like excess weight and high blood pressure,” he said. “The earlier you address these issues and manage them long-term, the greater the impact and the more likely you’ll have a healthy brain for the rest of your life.”
Originally published April 6, 2023, 3:41 AM