Millions of Americans may be suffering from sleep apnea – does this condition increase the risk of d

Recent research suggests that obstructive sleep apnea can interfere with oxygen supply during sleep, potentially elevating the risk of dementia. The study also found that women may have a higher prevalence of obstructive sleep apnea than men. However, experts caution that definitive evidence linking obstructive sleep apnea directly to dementia is still lacking, and further research is needed to clarify the relationship between the two.

This new study sheds light on the potential long-term effects of obstructive sleep apnea, a condition that reduces blood oxygen levels during sleep, on brain health. Tiffany Joy Braley, MD, associate professor of neurology at the University of Michigan Health School and co-founder of the Multiple Sclerosis Fatigue and Sleep Clinic, told Health magazine, "Obstructive sleep apnea is a common but underdiagnosed condition that is associated with key pathological changes in the brain, which overlap with many of the changes seen in patients with cognitive decline and dementia."

In addition to discovering a link between sleep apnea and dementia risk, researchers also noted that this association was more significant in women. Although experts have not yet pinpointed the cause, it may be related to an increased risk of cognitive problems in women. Galit Levi Dunietz, PhD, MPH, associate professor in the Department of Neurology and Sleep Medicine at the University of Michigan, pointed out that there are many reasons why women have a higher risk of dementia, including longer life expectancy, differences in health behaviors, and social determinants of health.

The study was published in the journal Sleep Advances last month.

Experts have varying opinions on the link between obstructive sleep apnea and dementia. If you have sleep disorders, the following information will help you understand how to protect your cognitive health.

How does obstructive sleep apnea affect the risk of dementia?

Experts note that this is not the first study to link obstructive sleep apnea with dementia. However, Nitun Verma, MD, MBA, spokesperson for the American Academy of Sleep Medicine, said, "This new study adds depth to the discussion with longitudinal data from 18,815 participants over a [10-year] period."

The study participants were from the Health and Retirement Study (HRS), a nationally representative sample of American adults. The study began in 1992 with participants aged 50 and older who did not have dementia. Researchers then tracked cases of dementia and documented who was diagnosed with obstructive sleep apnea or reported symptoms.

This method allowed researchers to "determine whether underlying signs of [obstructive sleep apnea]—even without a clinical diagnosis—can predict the likelihood of future dementia," said Braley.

Including participants with suspected sleep apnea in the analysis was also significant because an estimated 30 million Americans have the condition, but only 6 million have been diagnosed. Symptoms develop gradually and are often overlooked, and many Americans may not undergo the necessary sleep studies.

The study results showed that by age 80, women with confirmed or suspected sleep apnea had a 4.7% higher incidence of dementia, while men had a 2.5% higher incidence. Braley pointed out, "Adults with obstructive sleep apnea have a higher risk of future dementia compared to those without suspected or confirmed obstructive sleep apnea, especially women."

What causes sleep apnea?

Why are sleep problems closely related to cognitive health?

Although the study did not investigate this, experts have proposed several theories on how obstructive sleep apnea may affect dementia risk. Firstly, sleep disorders can make it difficult to obtain high-quality sleep, thereby increasing the risk of cognitive problems. Braley said, "Recent evidence suggests that sleep deprivation or sleep disruption, both consequences of obstructive sleep apnea, are associated with an increased accumulation of pathological biomarkers related to Alzheimer's disease."

She added that another possible explanation is that sleep apnea and sleep deprivation may alter immune system function, making it harder for the body to clear toxic substances in the brain associated with dementia. As for why the association between sleep apnea and dementia is more significant in women, hormonal differences may play a role, explained Dunietz. She said, "As women enter menopause, their estrogen levels decline, which may interact with sleep problems to increase the risk of dementia."

Gender differences in access to qualified care and healthcare may also be contributing factors. Verma said, "An important factor is that women may experience prolonged untreated suffering due to misdiagnosis or missed diagnoses. More research is needed to better understand and analyze this relationship."

Can menopause explain why Alzheimer's disease is more common in women?

Advice for those with symptoms of sleep apnea

The new study emphasizes that if you suspect you have obstructive sleep apnea, you should seek treatment. Braley said, "Identifying and addressing this impactful and treatable condition is an important step in supporting cognitive health."

Common symptoms of sleep apnea include snoring, daytime sleepiness, fatigue, inattention, headaches, or frequent nighttime awakenings to use the bathroom. Robson Capasso, MD, professor of otolaryngology and director of sleep surgery at Stanford Healthcare, reminded, "It's important to remember that there is currently no evidence that sleep apnea itself causes dementia. People should not panic about it."

Although more research is needed on the link between sleep apnea and brain health, poor sleep is indeed a concern. Sleep deprivation is associated with obesity, heart health issues, and type 2 diabetes. Therefore, Capasso recommended that people should try to control or address modifiable risk factors for sleep apnea if possible, such as excessive alcohol consumption, smoking, and obesity.

Verma added that if you have been diagnosed with the condition, it is crucial to monitor your symptoms and communicate with your doctor if they do not improve or worsen. He said, "Early identification, diagnosis, and effective treatment of obstructive sleep apnea are crucial as they may help mitigate adverse health consequences."