Most people with untreated sleep apnea develop heart disease, and researchers speculate that’s why they also have cognitive problems. But a new small study reveals that obstructive sleep apnea itself harms the brain, giving new urgency to recognizing and treating the disorder.
According to a study published Thursday in Frontiers in Sleep, healthy middle-aged men newly diagnosed with obstructive sleep apnea showed poorer mental function in areas such as judgement, impulse control and pattern recognition. feelings of others in relation to unaffected men.
Obstructive sleep apnea, the most common form, occurs when the throat muscles relax and the airways become blocked. Another type is central sleep apnea, which occurs when the brain doesn’t send the right signals to the muscles that control breathing. In both types, people are briefly awakened by the need for oxygen.
For the new study, the researchers recruited 27 men between the ages of 35 and 70 who were not overweight and had new diagnoses 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 passed a series of tests. Men with obstructive sleep apnea had cognitive deficits that increased with increasing severity.
It’s estimated that up to 26 percent of American adults between the ages of 30 and 70 suffer from sleep apnea, according to the American Academy of Sleep Medicine. That may be an underestimate, as the condition is vastly underdiagnosed, experts say. It is generally thought to affect men more than women.
Sleep apnea has been linked to problems with memory and thinking, but the new study finds cognition is affected even when men don’t have underlying health conditions, underscoring how important it is to treat it early, co-lead author Dr Ivana Rosenzweig, a neuropsychiatrist who runs the Sleep and Brain Plasticity Center at Kings 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 “if it weren’t for snoring and bothering their partners.”
The new study is small, and Rosenzweig would like researchers to conduct larger studies that include women.
Until menopause, women are much less likely to develop the sleep disorder; however, its prevalence in women increases dramatically with age and weight, Rosenzweig said.
“It almost stabilizes between the sexes after menopause,” she said.
What causes sleep apnea?
Why obstructive sleep apnea causes cognitive deficits is unclear, although scientists suspect that frequent, albeit short, awakenings lead to fragmented sleep and periods when breathing briefly stops cause temporary decreases in blood oxygen levels.
Risk factors for obstructive sleep apnea include:
Often people don’t know they have sleep apnea, Rosenzweig said. They usually only ask for help when their partner tells them there is a problem, such as snoring.
“There could be clues, such as morning headaches or increased sleepiness and fatigue during the day,” she said.
Sleep apnea may be worse for your health than insomnia because it can prevent the brain from falling into a deep sleep, said Dr. Joel Salinas, behavioral neurologist and researcher at NYU Langone Health and Isaac’s chief medical officer. Health in New York. .
The brain goes through different stages during sleep, including light and deep sleep and rapid eye movement, or REM, sleep, which is when dreaming occurs.
Deep sleep, also known as stage 3 sleep, occurs when memories are stored and the brain clears out proteins that could cause damage over time, said Salinas, who did not participate in the the new study.
“People with obstructive sleep apnea don’t spend a lot of time in stage 3, but wake up in stage 2 and then come back in stage 1,” he said.
“Over time, these people appear to have a higher accumulation of proteins, such as amyloid, which may increase the risk of cognitive impairment or dementia,” Salinas said.
Sleep apnea treatments
Doctors use many strategies to treat sleep apnea, said Dr. Andrew Varga, neuroscientist and physician at 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 airways open during sleep.
There are also mandibular advancement devices that hold the lower jaw forward to keep the airway open. “They are the second most popular method,” Varga said.
There are also operations to modify the structures of the throat. They can be as minimally invasive as removing the uvula, the fleshy structures hanging above the throat, and part of the soft palate, the muscular part of the roof of the mouth, Varga said.
Some patients rely on implantable pacemaker-like devices that tell nerves in the tongue to push it forward. At the more invasive end of the spectrum, there is surgery to reconstruct the jawbone. “The jaw is broken on both sides and then pulled forward,” Varga said.
Brain studies have shown decreased activity in areas similar to what’s seen in people with neurodegenerative diseases, Salinas said. That’s why it’s important to treat this type of sleep apnea early, he added.
Lifestyle changes are a good place to start, he said.
“It’s always important to address any potentially reversible issues, such as overweight and high blood pressure,” he said. “The sooner you address these issues and manage them long-term, the greater the impact and the more likely you are to have a healthy brain for the rest of your life.”