Sleep apnea may increase your risk of cognitive decline, dementiaShare on Pinterest
A new study suggests that sleep apnea is sufficient to “kick-start” cognitive changes. Grand River/Getty Images
  • A new study shows that obstructive sleep apnea may hasten cognitive decline in middle-aged men.
  • The research included 27 men between the ages of 35 and 70 with diagnosed obstructive sleep apnea and compared them to seven healthy men.
  • The results showed that men with severe obstructive sleep apnea showed deficits in vigilance, executive functioning, short-term visual recognition memory, and social and emotional recognition.

Obstructive sleep apnea might cause early cognitive deficits in middle-aged men, even those without comorbidities and obesity, according to a new study published in Frontiers in Sleep.

Lead researchers Ivana Rosenzweig and colleagues looked at a group of 27 men with a new diagnosis of mild to severe obstructive sleep apnea. The participants were between the ages of 35 and 70 and did not have obesity or any comorbidities. They were compared to a control group of seven healthy men.

The scientists confirmed the obstructive sleep apnea diagnosis with the WatchPAT test of respiratory function during sleep and via video-polysomnography at King’s College Sleep Center. They evaluated cognitive function via the Cambridge Neuropsychological Test Automated Battery of Tests (CANTAB).

The results of the study showed that men with severe obstructive sleep apnea showed deficits in:

The men with mild obstructive sleep apnea also showed some difficulties in these areas, but not as bad as those with severe forms of the disorder. In fact, they rarely performed significantly worse than the control group.

While most men with sleep apnea have medical comorbidities, those included in the study did not have comorbidities such as cardiovascular disease, diabetes, chronic inflammation, or depression. The authors noted that previous studies attributed cognitive deficits to comorbid conditions rather than sleep apnea.

“In our small proof-of-concept cross-sectional study, we demonstrated cognitive deficits in male patients with obstructive sleep apnea, even without any comorbidities,” said Ivana Rosenzweig, MD, Ph.D., FRCPsych, a sleep physician and consultant neuropsychiatrist, and lead author of the study in an email to Healthline. “This is highly significant, as the most prevalent school of thought currently is that obstructive sleep apnea-related comorbidities might be driving the cognitive deficits in this age group. Most patients with this disorder have already present comorbidities when we see them the first time in the — so it has always been close to impossible to delineate whether it was these diseases, or sleep apnea itself, that caused the damage.”

“Our study suggests that sleep apnea is sufficient to kick start cognitive changes,” Rosenzweig continued. “As most of these patients were (otherwise) healthy men with this disorder, most of them were consciously unaware that they were already sporting cognitive deficits picked up by the very sensitive testing battery.”

The researchers speculate that the cognitive difficulties could be due to the following:

  • Intermittent low oxygen
  • High carbon dioxide in the blood
  • Changes in blood flow to the brain
  • Sleep fragmentation
  • Neuroinflammation

They noted that sleep apnea is a potentially dangerous condition.

Sleep is a factor that can either be protective or risky for cognitive health,” says David Merrill, MD, PhD, 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, CA. “The effects of sleep on cognitive health depend on the attributes of an individual’s sleep, including the quality, quantity, frequency, and even the regularity of sleep. “

“With high quality, restorative sleep, the brain’s function is enhanced and protected as we age,” Merrill continued. “Chronically disrupted sleep can lead to several health issues, including headaches, fatigue, and memory loss that worsens over time.”

Obstructive sleep apnea is a sleep disorder characterized by the sleeper momentarily but repeatedly stopping breathing because the muscles in the back of the throat relax and collapse, blocking the airway, according to the National Heart, Lung, and Blood Institute (NHLBI)

The repeated disruption results in decreased oxygen levels and nonrestorative sleep. People with sleep apnea frequently exhibit loud, disruptive snoring and daytime sleepiness.

Between 25 and 30 percent of men and between 9 and 17 percent of women in the United States meet the criteria for obstructive sleep apnea, according to a 2022 article published on PubMed. People with a higher risk of developing it include:

  • Hispanic, Black, and Asian populations
  • People over the age of 50
  • Obesity

There might also be a genetic component.

“Patients with obstructive sleep apnea should receive comprehensive evaluation and treatment plan under the direction of the sleep specialist,” said Rami N. Khayat, MD, a UCI Health specialist in sleep medicine, pulmonary disease, and critical care medicine. “This treatment plan includes regular check-ins and follow-ups. During these follow-ups, the sleep provider reviews the response to treatment. “

“Generally, patients with sleep apnea on treatment have much less worry about cognitive decline than individuals who have undiagnosed or untreated sleep apnea,” Khayat continued. “These individuals should monitor their symptoms for sleepiness, fatigue, decreased attention, mood changes, and most importantly, sleepy driving.”

Sleep apnea could significantly increase the risk of dementia, such as Alzheimer’s disease. But it doesn’t seem to increase the risk of developing vascular dementia, according to a review of studies published in 2022.

“Sleep disturbances increase dementia risk, but unfortunately, dementia can also lead to sleep disturbances,” Merrill told Healthline. “So, you can end up with worsening memory to the point of dementia, which then worsens sleep. In this way, disrupted sleep can be part of a downward spiral, making it even more critical to identify and treat sleep issues during early and mid-life adult development.

“Dementia disrupts sleep in several ways,” Merrill continued. “Dementia is a neurodegenerative disorder, meaning that brain cells dysfunction and progressively die over time. As a person loses brain cells, the brain’s sleep centers start to dysfunction – we lose the ability to send signals to stay asleep. Often, sleep becomes fragmented or even inverted such that patients are awake all through the night, then sleep during most of the day.”

“Ideally, sleep will be optimized years before the potential onset of dementia,” Merrill continued. “The hope is that with improved sleep, we can delay the age of onset of dementia. The goal of improving sleep is to extend a person’s health span for as long into their life as possible.”

According to the CDC, adults 61 to 64 should optimally get seven to nine hours of sleep per night; for 65 and older, seven to eight hours is ideal.

One of the most effective treatments for obstructive sleep apnea is using a continuous positive airway pressure (CPAP) machine. These machines work by pressurizing air that is delivered through a hose and works to keep the airways open, according to the NHLBI.

But there are also self-care techniques that can be used at home to help relieve some of the symptoms and promote a good night’s sleep. Dr. Laura DeCesaris, a functional medicine-trained health professional, offers the following tips for managing sleep apnea:

  • Manage stress more effectively and pay attention to where your body holds stress. Many people hold tension in their neck and shoulders, resulting in this forward head carriage and posture that’s not conducive to proper breathing (both day and night). This is important for desk workers too.
  • Look at your sleeping posture (side sleeping can sometimes help with symptoms)
  • Pay attention to chronic inflammation in the gut and nasal passages, which often make it difficult to breathe through the nose. Modifying the diet and switching toward a more anti-inflammatory diet where possible can help. Sometimes certain foods can make you feel congested, worsening the issues experienced with sleep apnea
  • Exercise regularly
  • Stay hydrated and try out a humidifier in the bedroom, especially if you live in a dry climate