The Relationship Between Obstructive Sleep Apnea and Dementia

April 11, 2023

woman suffering from OSA sleep with CPAP device — Image by Brian Chase via Shutterstock

Dementia is a chronic condition that affects thinking, memories, and reasoning (cognitive abilities) and interferes with a person’s daily life and activities. Obstructive sleep apnea (OSA) is a sleeping disorder in which a person’s airway is closed off and on during sleep, which causes oxygen deprivation. Having OSA increases the risk of developing dementia.

Dementia is a chronic condition that affects thinking, memory, and reasoning (cognitive abilities) and interferes with a person’s daily life and activities.
Obstructive sleep apnea (OSA) is a sleeping disorder in which a person stops breathing several times during the night.
Having OSA significantly increases the risk of developing dementia.
The treatment of choice for OSA is continuous positive airway pressure (CPAP). Consistent use of CPAP is the key to long-term benefits.
For people with dementia, regular CPAP use for OSA can slow the advancement of dementia. For OSA sufferers without dementia, regular CPAP use decreases the risk of developing dementia.

Dementia statistics

More than 7 million Americans over 65 had dementia in 2020. Without a treatment breakthrough or cure, this number is expected to rise, especially as the Baby Boomer generation ages. If current trends continue, there will be 9 million Americans with dementia by 2030 and 12 million by 2040. Dementia primarily affects older people, but dementia is not a normal part of aging. Several recent studies show that obstructive sleep apnea significantly increases a person’s risk for dementia.

What is obstructive sleep apnea (OSA)?

OSA is a sleep disorder which causes a person to stop and restart breathing several times throughout the night. This can cause a lack of oxygen or a shortage of oxygen. The tongue and soft palate relax fully or partially and block (obstruct) the airway off and on through the time of sleep.

Besides oxygen deprivation, OSA may also cause someone to wake up several times throughout the night. This kind of sleep is called non-restorative sleep and causes daytime sleepiness.

Non-modifiable risk factors for OSA

There are risks for OSA that cannot be changed. These are called non-modifiable because of being out of the person’s control.

Here is a list of non-modifiable risk factors for obstructive sleep apnea:

Age. Risk for OSA increases with age.
Gender. Men are more likely to have OSA than women.
Family history and genetics. OSA or factors leading to OSA can be inherited.
Heart or kidney failure. Can cause fluid buildup in your neck that may lead to OSA.
Large tonsils or a thick neck. Can cause airway blockage during sleep.

Modifiable OSA risks

Other risks for OSA can be changed. These are called modifiable (changeable) because they can be improved with lifestyle changes.

Obesity. A body mass index (BMI) greater than 35 increases the risk of developing OSA.
Alcohol. Drinking alcohol can make the muscles of the throat and upper airway relax, which increases the chances of OSA.
Smoking. Smoking causes inflammation, which may lead to OSA.

Maintaining a healthy weight, stopping smoking, and decreasing or stopping alcohol use can improve or eliminate the modifiable risks of OSA.

Diagnosing OSA

A healthcare provider (HCP) may use STOP-BANG, the most widely accepted OSA screening tool, which has been validated through research. STOP-BANG evaluates the signs and symptoms of OSA, including snoring, tiredness, observation, pressure of blood, BMI, age, neck circumference, and gender.

If your healthcare provider decides to apply this tool for diagnosing OSA, you will be asked the following questions:

Question:	Answer:
Do you snore loudly?	Yes/No
Do you often feel tired during the daytime?	Yes/No
Has anyone observed you stop breathing during your sleep?	Yes/No
Do you have or are you being treated for high blood pressure?	Yes/No
Is your BMI higher or equal to 35 kg/m2?	Yes/No
Are you older than 50 years old?	Yes/No
Is your neck circumference longer than 40 cm?	Yes/No
Are you a male?	Yes/No

Usually, healthcare providers use STOP-BANG tool to decide whether there is a high probability of moderate to severe disease. You are at high risk if you answer “Yes” to 3 or more questions, and at low risk if you positively respond to less than 3 questions.

A healthcare provider will refer a patient with a high-risk STOP-BANG score to a specialist, such as an ear, nose, and throat (ENT) doctor. The specialist will perform a careful medical history and physical examination and may recommend more testing to confirm the OSA diagnosis and severity.

Sleep studies

One study used to confirm OSA is called a polysomnogram or, more commonly, a sleep study. A sleep study is used to diagnose sleep disorders, including OSA, and is performed at a sleep center or home. The sleep specialist and the patient will work together to determine the best location. The sleep study monitors and records brain waves and muscle activity during sleep. The sleep study tracks how often a person stops breathing during sleep. An OSA diagnosis and treatment plan will be based on the combined outcome of the patient’s history, physical, and test results.

OSA significantly increases dementia risk

An analysis and review of eleven studies examining the association between sleep apnea and dementia was published in the Journal of Sleep Research in October 2022.

This review determined that sleep apnea is associated with a significantly increased risk of dementia, particularly Alzheimer’s and Parkinson’s disease.

Recent research also shows that OSA is a modifiable risk factor for dementia. Treatment of OSA for those middle-aged and older adults without symptoms of cognitive impairment decreases their risk of dementia. In addition, treatment of OSA for those with mild cognitive impairment or dementia improves the quality of life by slowing or stopping dementia progression.

Treatment for OSA

There are several treatment options for OSA. However, the current treatment of choice is continuous positive airway pressure (CPAP).

A CPAP device uses mild continuous air pressure to keep airways open during sleep. The CPAP device comes with a mask that fits over the nose or the nose and mouth and is worn while sleeping, including when napping.

Benefits of CPAP

The early benefits of CPAP are better sleep quality, more energy, increased physical activity, decreased anxiety and depression, decreased snoring, and less daytime sleepiness. In addition, there are long-term benefits that come with regular use.

One of the long-term benefits of CPAP is a decrease in mild cognitive impairment, which can lead to dementia, and a reduction in the advancement of Alzheimer’s disease, the most common form of dementia. In addition, other long-term CPAP benefits include lowering high blood pressure and decreasing stroke risk.

The benefits of CPAP are realized only with consistent use: use CPAP when sleeping, every time, including napping. It is vital to work with a healthcare provider to find the mask that works best and to follow all directions of the CPAP device to maintain cleanliness and operation. Consistent use of CPAP for OSA increases the overall quality of life.

For someone with dementia, regular CPAP use may improve daily functioning, leading to more independence and lightening the caregiver's load. Current research establishes that diagnosis and treatment of OSA are significant to the middle-aged and older population. Therefore, anyone with symptoms of OSA should ask to be evaluated by their healthcare provider.

If diagnosed with OSA, get treatment, and stick to the plan. The long-term benefits of OSA treatment offer positive benefits to physical and brain health.