Can Sleep Apnea Cause Memory Problems?

Do you often wake up feeling unrested even after a full night's sleep? Chances are, your brain does not have enough time to sort and consolidate your memories.

If you or someone you care about has been diagnosed with obstructive sleep apnea (OSA), you might be wondering if it could affect memory or increase the risk of Alzheimer's disease (AD).

In a 2018 study led by Andrade, Bubu, Varga, and Osorio, a potential connection between OSA and AD was discovered. We break down this research to help you enhance your sleep health in this article.

Understanding Obstructive Sleep Apnea (OSA)

OSA is a common sleep disorder where your upper airway repeatedly collapses during sleep. This disrupts breathing patterns, causing you to gasp for air or experience brief periods where you stop breathing altogether. These interruptions not only affect sleep quality but can also have broader health implications.

The Link Between OSA and Alzheimer's Disease

The study by Andrade et al. sheds light on a potential link between OSA and AD, a progressive neurodegenerative disorder that affects memory, thinking, and behavior. Alzheimer’s is the most common form of dementia across the globe. Its established risk factors include traumatic brain injury, depression,midlife obesity, diabetes and cardiovascular disease.

Like AD, OSA is also more common among older populations. Sleep apnea has also been linked to cognitive decline and dementia. Here’s how:

Disrupted Sleep Architecture

OSA causes reflex responses that continually “wake” the brain. This leads to sleep fragmentation, or disruptions during sleep. Frequent awakenings caused by OSA can disrupt the brain's natural sleep cycles, which are crucial for memory consolidation and overall cognitive function. In turn, impaired memory and attention processes increase one’s risk for dementia.

Further, OSA disrupts REM and SWS sleep. REM sleep is crucial to memory promoting processes. When OSA disrupts this stage, memory consolidation is also put on hold. This leads to higher cognitive decline over time.

Meanwhile, SWS (slow-save sleep) or deep sleep, is more resistant to OSA compared to lighter sleep stages. However, in patients with severe OSA, SWS sleep can also be disturbed. SWS disruption interferes with overnight memory, learning, and visuomotor performance. Hence, OSA-disrupted deep sleep contributes to cognitive impairment and increased Alzheimer’s risk.

Intermittent Oxygen Deprivation

During apnea episodes, oxygen levels drop. This lack of oxygen can damage brain cells and contribute to the development of AD-related changes in the brain. Several rodent studies have shown that intermittent hypoxia causes oxidative stress, which increases neuron loss and reduces spatial learning.

Cardiovascular Risks

OSA often occurs alongside conditions like high blood pressure, which are also risk factors for AD. This suggests a potential overlap in the underlying mechanisms of these conditions.

Overall, OSA and AD frequently coexist and are said to have an “interdependent relationship,” where around half of AD patients experience OSA after their diagnosis.

Can AD Affect Sleep Apnea?

Andrade's study revealed an interesting twist. The neurological changes associated with AD could potentially worsen sleep apnea by affecting the muscles that control the airway. This creates a two-way street where OSA and AD influence each other, and OSA worsens a patient’s existing dementia.

OSA’s Impact on Cognitive Function

Cognitive decline, including memory problems, is a major concern for people with OSA.

Andrade's research found that a significant portion of OSA patients are likely to develop mild cognitive impairment (MCI). Since MCI can be a precursor to AD, it is clear that addressing OSA to protect both sleep quality and cognitive health.

In a subgroup analysis of the same study, OSA patients were found to have twice the risk of experiencing cognitive decline and/or dementia compared to non-OSA patients.

Why We Need More Research

While the aforementioned study offers valuable insights, there's still much to learn about the OSA-AD connection. Quantifying their relationship is also complicated because OSA is complex and heterogeneous. For example, OSA risk factors are different across age groups.

Still, OSA has a significant impact on the progression of AD due to sleep disruption, hypoxia, and other comorbidities. Last but not least, although AD is currently not treatable, treating sleep apnea may help prevent OSA-associated cognitive decline.

Take Control of Your Sleep Health

In other words, managing OSA can not only improve your sleep but also potentially lower the risk of acquiring or worsening AD. Below are some steps you can take.

Embrace BiPAP Therapy

If you've been diagnosed with OSA and prescribed a Bilevel Positive Airway Pressure (BPAP or BiPAP) machine, consistent use is crucial. BiPAP helps you get enough oxygen and/or get rid of carbon dioxide, potentially supporting cognitive function.

Prioritize Healthy Habits

Maintain a healthy lifestyle through regular exercise, a balanced diet, and weight management. These habits can alleviate OSA symptoms and promote brain health. Physical activity and proper nutrition are key for restful sleep and optimal brain function.

Consider Oral Appliances

For those who find CPAP therapy challenging, oral appliances can be an alternative.These devices help maintain an open airway during sleep, reducing breathing disruptions and improving sleep quality. Another effective second-line treatment option is the surgical implant Inspire.

Monitor Your Cognitive Function

Be aware of any changes in memory, attention, or reasoning. If you notice persistent cognitive difficulties or behavioral changes, seek evaluation from a healthcare professional specializing in sleep disorders and cognitive health.

A Roadmap for Overcoming OSA and AD

The link between OSA and AD underscores the importance of a comprehensive approach to health that targets both sleep and brain health. Understanding this connection means taking steps to manage OSA and promote a sharper brain.

The sleep experts at nightly are ready to help you optimize OSA treatment for a healthier body and mind. We also offer virtual consultations and a health sleep dashboard to help you monitor your sleeping habits and their impact to your overall well-being. All our treatments are personalized, so you can rest assured that you will receive a treatment suited to your age, medical condition, and unique sleep needs.

Take our free sleep assessment today!

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