Sleep apnea is a common but often undiagnosed sleep disorder characterized by interruptions in breathing during sleep. These interruptions, known as apnea, last from a few seconds to minutes and can occur several times an hour. The most common type of obstructive sleep apnea (OSA) occurs when the muscles in your throat relax too much, causing your airway to become blocked.
Symptoms include loud snoring, excessive daytime sleepiness, and restless sleep, which can significantly affect your quality of life. About 6 million Americans are diagnosed with sleep apnea, but estimates suggest that up to 80% of adults with OSA go undiagnosed.1 That means nearly 30 million Americans struggle with sleep apnea, most of whom don’t even know it.2
This high prevalence highlights the importance of awareness and screening, especially as OSA is not only a nuisance but is associated with several serious health problems. In general, men are more likely to be diagnosed with OSA than women, but studies show that women suffer worse consequences from the disease, especially when it comes to cognitive health.3
The relationship between sleep apnea and dementia
The findings of a comprehensive 10-year longitudinal study published in SLEEP Advances show an association between known or suspected OSA and the risk of developing dementia, particularly among older women.
The study analyzed data from the Health and Retirement Study (HRS), which included 18,815 participants age 50 and older who were dementia-free at the start of the study. By following these individuals over a decade, researchers aimed to determine how OSA affects the risk of developing dementia.
The results were clear. Both women and men with known or suspected OSA showed higher rates of dementia compared to those without OSA. Specifically, by age 80, women with OSA have a 4.7% increased risk of dementia, while men have a 2.5% increased risk.4 The association remained significant even after adjusting for factors such as race, education, and cohabitation, emphasizing that OSA is an independent form of dementia.
Why are the elderly particularly at risk?
The study found that women with OSA had a disproportionately high risk of developing dementia. Several factors contribute to this gender-specific vulnerability. Women with untreated OSA experience severe symptoms, including poor sleep quality, increased fatigue, anxiety, and depression.5 These downstream effects have a more pronounced effect on cognitive function over time.
Women are also more likely to suffer from OSA-related cardiovascular problems, such as high blood pressure and heart disease, which are themselves at risk for dementia. The association of OSA with other health conditions exacerbates cognitive decline in women, making them more susceptible to dementia than their male counterparts.
A major challenge in addressing OSA-related dementia is the large number of undiagnosed cases. The study used the integrated STOP-Bang questionnaire, a validated screening tool, to identify both diagnosed and suspected cases of OSA.
By addressing these uncertainties, the research provides a more accurate estimate of the true prevalence of OSA and its impact on cognitive health. This is important because undiagnosed OSA remains untreated, allowing the disease to continue and accelerate cognitive decline. Early detection and treatment of OSA can play an important role in reducing the risk of dementia, especially in at-risk elderly women.
The relationship between OSA and dementia is complex, involving multiple biological and physiological mechanisms. Chronic obstructive sleep apnea leads to intermittent hypoxia (low oxygen levels) and fragmented sleep, both of which place significant stress on the brain.
This can contribute to the accumulation of stress Amyloid beta and tau proteinsCharacteristics of Alzheimer’s disease, the most common form of dementia. In addition, OSA is associated with systemic inflammation, which impairs cognitive function and promotes neurodegeneration.
Sleep reinforcement – a key player in cognitive function
Beyond the well-documented risks associated with OSA, research highlights the role of improving sleep in maintaining cognitive health as you age. Sound sleep refers to uninterrupted, continuous sleep that allows your brain to efficiently cycle through the different stages of sleep.
A JAMA Network Open study of 5,946 middle-aged to older adults found that better sleep maintenance efficiency—basically, nocturnal awakenings—and reduced wake times after sleep onset were strongly associated with better global cognitive function.6
Think of your sleep as a symphony, each instrument representing a different stage of sleep. As your sleep deepens, these “instruments” pause and play in harmony without disturbance.
This seamless progression in sleep stages is involved in processes such as memory consolidation. Disruptions in this flow impair your ability to recall memories, solve problems, and maintain focus—key components of cognitive health.
In short, improving your sleep continuity is essential to maintaining cognitive function and addressing sleep apnea, which leads to fragmented sleep, is part of that equation. According to the study, “Poor sleep consolidation and prevalence of OSA were associated with poorer global perception over five years.”7 Increasing support for the importance of OSA in preventing cognitive decline.
Understanding the Biological Mechanisms Linking OSA and Dementia
The association between OSA and dementia suggests complex biological mechanisms underpinning this association. One of the main mechanisms is intermittent hypoxia, a hallmark of OSA. When it happens dramatically, your oxygen levels drop, leading to a period of low oxygen, then re-oxygenation begins. This cyclical pattern creates oxidative stress and inflammation in your brain.8
Another pathway is the glymphatic system, which is responsible for clearing metabolic waste from your brain. OSA-induced intracranial pressure fluctuations disrupt normal cerebrospinal fluid flow, impairing the glymphatic clearance of amyloid beta.
Sleep distribution also plays an important role. Persistent sleep is essential for processes such as memory consolidation and synaptic remodeling. When sleep is interrupted, these processes are disrupted, which causes deficits in memory, attention and executive functions.9 Over time, this chronic disruption contributes to the gradual decline in cognitive abilities seen in dementia.
Moreover, the chronic persistent hypoxia and increased sympathetic activity associated with OSA creates a vicious cycle that threatens cardiovascular health and cognitive function.
Neuroimaging studies have provided concrete evidence of the effects of OSA on brain structure. OSA patients often show white matter lesions and gray matter atrophy in regions critical to cognitive processing. These structural changes are associated with impairments in memory, executive function, and processing speed, further linking OSA to cognitive decline and dementia.10
Mouthguards, OMT and CPAP for the treatment of sleep apnea
Continuous positive airway pressure (CPAP) is considered the “gold standard” for treating OSA.11 This therapy involves a small device that provides a constant flow of air through a mask worn over your mouth, nose, or both. Uninterrupted air pressure prevents your airways from constricting during sleep, maintaining oxygen levels and improving sleep quality.
However, CPAP therapy has its drawbacks. Some individuals may feel claustrophobic wearing the mask, and common side effects include nasal congestion, dry mouth and eyes, and facial lacerations from the mask’s pressure points. Alternatively, Mandibular growth tools (MADs), a type of mouth guard, provides effective treatment with fewer side effects compared to CPAP.
MADs are customized by dentists in collaboration with sleep specialists. These appliances consist of two parts that fit over your upper and lower teeth and are connected by a mechanism that slowly moves your lower jaw forward. This position moves the base of your tongue away from the windpipe, reducing the chance of obstruction.
Dentists perform a thorough examination and take x-rays to determine the exact amount of movement your lower jaw needs to keep the airway open. Adjustments are made gradually so as not to change your bite or cause jaw discomfort.
It is another treatment option orofacial myofunctional therapy (OMT) OMT focuses on neuromuscular re-education of your oral and facial muscles through exercise and behavior modification techniques. These exercises encourage proper tongue position, correct breathing, chewing and swallowing, and correct head and neck posture. OMT is particularly effective in treating mild to moderate sleep apnea and offers significant benefits.
Lifestyle modifications to relieve sleep apnea
Dysfunctional breathing habits They can damage your health and worsen conditions like sleep apnea. I recommend consulting with a Breathing Behavior Analyst to help you learn what triggers your breathing habits and how to resolve them. This is an important step in controlling sleep apnea.
In addition to proper breathing, adopting certain lifestyle changes can significantly reduce the symptoms of sleep apnea, which includes snoring. Depending on the severity of your condition, these adjustments are often the most effective:12
- Maintain a healthy weight- Being overweight is a risk factor for sleep apnea. If you are overweight, losing even 10% of your body weight can lead to significant improvements in sleep apnea symptoms.
- Choose the right sleeping position: Sleeping on your back often makes sleep apnea worse because it causes your tongue and soft palate to fall back and block your airway. Instead, try sleeping on your side or stomach, or with your upper body elevated.13 To prevent rolling on your back while you sleep, try simple tricks such as tying a tennis ball to the back of your pajamas or using strategically placed pillows.
- Avoid alcohol and smoking Alcohol and smoking both worsen the symptoms of sleep apnea. Alcohol relaxes your throat muscles, increasing the risk of airway obstruction, while smoking can lead to inflammation and fluid retention in the airways.
- Avoid benzodiazepines – These sedatives can make sleep apnea worse by relaxing the muscles in your throat, which makes the airway more closed.
Acquiring this knowledge empowers you to make informed decisions about your health, reducing the risks of cognitive decline so you can enjoy a better quality of life. Prevent sleep apnea from quietly contributing to your cognitive challenges—seek evaluation and comprehensive treatment to protect your mental health in the future.
