Poor sleep quality from sleep apnoea may raise your dementia risk

By Oluwasola Samuel, Freelance Health writer. With medical review by the DLHA Team.

A black couple sleeping in bed

When we think about our health, quality sleep isn’t always the first thing that comes to mind. A good night’s sleep is something many take for granted. It turns out that quality sleep not only helps us feel refreshed, but it could actually help protect our brain health.  

This might sound strange and new to many, but it's worth finding out how and why this is so.

A recent research from the University of Michigan shows that having poor sleep quality, especially from conditions like sleep apnoea, could increase your risk of dementia or higher order brain function as you age, and especially in women. 

Before diving deeper into the study, let's understand what sleep apnoea is

What Is Sleep Apnoea?

Sleep apnoea occurs in three major types; central, obstructive and complex. Obstructive sleep apnoea (OSA) is the most common type.

When OSA occurs, you will experience interrupted breathing or your breathing may temporarily stop. This happens when the muscles around the soft tissues at the back of your mouth and throat relax and completely block or narrow the airways in your throat when you are sleeping. This causes your lungs to be deprived of air and your blood deprived of oxygen. 

OSA can happen many times (10-100) at night, leading to poor-quality sleep, snoring, restlessness, and oxygen deprivation. Over time, if you leave it untreated, it can lead to health complications like high blood pressure, heart problems, and chronic inflammation. 

“If sleep apnoea is not diagnosed early or left untreated, it can lead to cognitive decline and poor performance." said Dr. Tiffany Braley, who is the lead researcher in the study.

About the Study 

The US study aimed to evaluate sex-specific associations between known or suspected obstructive sleep apnea (OSA) and dementia risk among older women and men. It tracked over a ten year period, 18,500 adults aged 50 and older that included 11,023 women (54%) and 7,792 men (46%). The participants were dementia free at the beginning of the study. It then analysed the sleep quality and cognitive health of the participants over time. 

Key Findings from the Study

The study found that OSA is a significant risk factor for dementia onset with a higher impact on women. It highlights the causal impact that a potentially modifiable risk factor has on dementia development. 

Here are some facts and figures from the study:

• 9% of women and 8% of men in the study, turned out to meet the benchmark for dementia during the study period. 

• Known/suspected obstructive sleep apnoea was more common in men than in women.

• Known/suspected obstructive sleep apnoea was associated with a higher rate of dementia across ages 60–84 years for both women and men. 

• By age 80, women with known or suspected obstructive sleep apnoea relative to those without had a 5% higher dementia risk compared to 2.5% for men.

“The 5% may seem like a small percentage, but this number is significant, especially because it remains steady even when accounting for other dementia risk factors like race and education.” Braley added.

Researchers noted that obstructive sleep apnoea affected men and women differently as older women with sleep apnea compared to those without were found to have a higher risk of dementia than men of the same age. This was surprising and the reasons for the observation aren’t entirely clear yet. 

It is possible that the difference could be as a result of the sensitivity of the aged female brain to the chronic inflammation associated with OSA post menopause.

“Estrogen starts to decline as women transition to menopause, which can impact a woman’s brains.” said Galit Levi Dunietz, study co-author and an associate professor in the university's division of neurology and sleep medicine. 

"During that time, women are more prone to memory, sleep, and mood changes that may lead to cognitive decline. Sleep apnoea increases significantly post-menopause yet remains under-diagnosed." Dunietz added.

There are some biological effects as a result of disrupted sleep, which can impact brain function and health.

“Disrupted breathing associated with sleep apnoea leads to poor-quality sleep, which can cause inflammation in the brain. Over time, this inflammation might contribute to cognitive decline. Braley added.

One important thing to note about this research is that it wasn't exclusively done to prove that sleep apnoea causes dementia. This research only shows a strong connection between the two.

“Healthcare providers trying to treat patients would likely require a randomised trial over many years to compare the effects of sleep apnoea treatment to the effects of no treatment," said Dr. Ronald Chervin, study co-author, and Director, Division of Sleep Medicine at U-M Health.

What the Study Means for Africans

Dementia in Africa is a growing concern, and this study should help African researchers to focus on some less known risk factors of dementia. Sleep disorders like sleep apnoea can be easily overlooked in African countries, where access to health information, quality healthcare, and specialist sleep physicians are limited. 

Sleep apnoea is often undiagnosed, as many people may not associate fatigue or memory problems with a serious sleep disorder. There are a lot of stigmas around mental and cognitive health in Africa, and this may make it difficult for people to seek help, especially older women who were identified to be at a higher risk of association of sleep apnoea and cognitive decline. 

The findings of this study should serve as a wake-up call for Africans on the essential long-term health benefit of sleep and why ignoring poor sleep patterns may increase your risk of dementia as you age. 

It’s important to recognise symptoms of sleep apnoea, such as loud snoring, frequent waking up at night and gasping for air, or excessive daytime sleepiness. This will help you to seek medical help early and get appropriate diagnosis and care for the condition before it affects your cognition. 

For Africans, where resources may be limited, simple lifestyle changes, like avoiding alcohol before bed, losing weight, or changing sleep positions, can make a huge difference in sleep apnoea.

Improving local community awareness, support, and health education about sleep apnoea and cognitive health in Africans are important tasks that needs to be addressed by public health managers in collaboration with other health stakeholders.

Wrap up

Sleep is more than just a way to rest at the end of the day. Quality sleep is crucial for achieving and maintaining a healthy body and a sound mind. The good news about sleep apnoea is that treatment is available. Diagnosing and treating sleep apnoea early can help protect your brain’s health in the long run. Whether you live in an urban or a rural area, you need to understand your level of risk and advocate for better health services that can help protect you and loved ones 

Africans need improved awareness about sleep as an essential part of health and well-being. You can prevent the impact poor sleep quality has on your brain’s health by being self-aware.

Prevent cognitive decline; talk with your healthcare provider early about any sleep problems that you may have.

Source:

Braley TJ, Lyu X, Dunietz GL, Schulz PC, Bove R, Chervin RD, Paulson HL, Shedden K. Sex-specific dementia risk in known or suspected obstructive sleep apnea: a 10-year longitudinal population-based study, SLEEP Advances, 2024; 5(1), zpae077, doi: 10.1093/sleepadvances/zpae077. Available from here.

Related:

Sleep disorders - An African Perspective: Types and Symptoms

10 things Africans should be doing to lower dementia risk

Dementia: What Africans need to know

Education, Wealth and Job Status Affects your Dementia Odds; Study

Sleep apnea may be linked to higher levels of Alzheimer's biomarker in brain

Published: November 25, 2024

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