relationship between sleep apnoea and memory loss

Sleep apnoea sufferers are characterised by their loud and persistent snoring, while some are known to choke and gasp for air during sleep. “Apnoea” is a Greek word that translates to “without breath”. For most, sleep apnoea results in poor quality and fragmented sleep for the sufferer.

Obstructive sleep apnoea (OSA) is a sleep disorder that hinders the ability to breathe properly. It occurs when the muscles that control breathing fail to keep the airway open, resulting in brief pauses in breathing for up to 10 seconds or more. This usually happens during sleep when the muscles are in a relaxed state.

In this article, we will take a look at available evidence that shows the relationship between obstructive sleep apnoea and cognitive impairment, which includes dementia and early onset of Alzheimer’s. Besides showing the possible ways in which untreated sleep apnoea contribute to the acceleration of cognitive decline, this article will explore the causes of obstructive sleep apnoea, its treatment options as well as other relevant health concerns related to the sleeping disorder.

Poor quality sleep hastens memory loss (Alzheimer’s disease)

sleep apnoea and memory loss

The physical obstruction of the breathing passages not only interferes with your sleep but also decreases the oxygen levels in your blood system. Research shows that oxygen desaturation as a result of untreated sleep apnoea can also impair brain function and lead to memory loss.1,2,3

As opposed to normal oxygen levels of 94-98%, sleep apnoea sufferers may find their oxygen levels falling to 80% or less.1 Reduced oxygen in your blood can affect the normal functions of your internal organs and aggravate other existing health conditions.2

According to the findings of a study published in the journal Neurology, sleep apnoea sufferers or snorers were diagnosed with mild cognitive impairment more than 10 years earlier than those without the condition.2,3 The average age that a OSA patient starts to experience cognitive impairment is 77, as compared to 90 for those without breathing problems.2,3

The research concluded that untreated sleep apnoea may contribute to more rapid onset of Alzheimer’s disease. As mentioned, sleep deprivation is caused by the breathing interruptions (or apnoea events) that occur throughout the night. On average, an adult requires about 7-8 hours of sleep per night. About one quarter of your sleeping time is spent in the deepest phase of sleep.

Since an apnoea event – an instance of breathing pause that lasts for 10 seconds or longer – occurs approximately once every minute, the OSA sufferer is deprived of the adequate rest that he or she requires in order to function properly the next day. But that’s not all.

Your brain contains toxins, including harmful proteins known as amyloid-beta. The glymphatic system acts as the brain’s waste removal system. What it essentially does is clear out the harmful toxins and prevents them from accumulating in your brain. The build-up of amyloid-beta has been linked to Alzheimer’s disease. However, the glymphatic system operates during deep sleep. Since OSA sufferers lack the sufficient rest during sleep, they risk allowing the harmful waste to accumulate and develop into Alzheimer’s disease.2,3

According to the study’s co-author, Dr Andrew Varga, who is also an instructor in medicine at the New York University Sleep Disorders Centre, some parts of the brain are more affected by low oxygen levels than others.

Varga revealed that sleep apnoea may “stress out” certain neurons in the hippocampus where predominantly Alzheimer's is thought to start, as “these neurons are exquisitely sensitive to drops in oxygen”.4

Disturbed sleep may lead to an accumulation of the proteins that “gunk up nerve cells”, said Dr. Mark Wu, associate professor of neurology at Johns Hopkins Medicine and sleep medicine specialist.4

It is important to note that Alzheimer’s disease (memory loss) remains untreatable, and represents billions of dollars in healthcare costs around the world. On the other hand, there are treatment options available to either cure or reduce the symptoms of obstructive sleep apnoea.

Treatment options for obstructive sleep apnoea

obstructive sleep apnoea treatment

Most people with obstructive sleep apnoea are not diagnosed until there is a dire consequence, such as a car accident due to excessive sleepiness or when OSA patients develop a stroke or high blood pressure. Besides memory loss, untreated obstructed sleep apnoea is associated with medical problems including diabetes, high blood pressure and increased risk of stroke.5 Common symptoms of the condition include loud and persistent snoring, daytime sleepiness and fatigue as well as a lack of concentration.

Depending on the severity of your Obstructive Sleep Apnoea, the disorder can usually be effectively managed or treated with one of the following options:

Continuous Positive Airway Pressure (CPAP)

Typically used as a first choice prescription, CPAP uses air pressure to keep the palate, nose and throat tissues open so that they do not block the air passage, thus allowing the patient to breathe normally while asleep. The CPAP machine consists of a portable unit with an attached face/nasal mask connected via tubing.

Despite its effectiveness and widespread recommendation, it is estimated that only 23% - 45% of patients have success with the CPAP method.6 This is probably due to the fact that not everyone can tolerate sleeping with the face mask, not to mention the constant blowing of pressurised air through one’s nostrils and throat throughout the night.

Dental appliances

Dental appliances are also recommended as one of the first line treatment options, along with CPAP. Oral appliance therapy is frequently recommended for patients who fail to comply with CPAP treatment.

The Mandibular Advancement Splint/ Device (MAS/ MAD) is one of most popular dental appliances used for treating OSA. Designed to fit snugly inside your mouth, the MAS/MAD works by repositioning the mandibular – the lowest facial bone that holds the teeth in place – such that it prevents your tongue from blocking your airway during sleep.

A sleep dentist is able to supply and fit the oral appliance in your mouth. The teeth-hugging device consists of a set of splints – for your upper/ lower jaws – that can be further adjusted for optimum comfort and effectiveness throughout the treatment process.

Lifestyle changes

Obesity is one of the main causes of OSA, hence sleep therapists frequently recommend weight loss programs, nutritional diet and exercise as a treatment option to counter the effects of the breathing disorder. Other lifestyle-driven methods include change of sleeping position as well as quitting or cutting down of tobacco and alcohol intake.

Obstructive Sleep Apnoea is a potentially serious breathing condition that affects your health as well as lifestyle.

A Sound Sleeper Dentist is able to help with your sleeping disorder and provide a solution for your snoring condition. Click here to locate a Sound Sleeper dentist near you today.

References

  1. "Sleep Apnea Oxygen Level: Symptoms, Causes, Cures and Treatment Options." Sleep Apnea Guide. Accessed December 18, 2015. http://www.sleep-apnea-guide.com/sleep-apnea-oxygen-level.html.
  2. Merkola, Joseph. "Sleep Apnea Linked to Speedier Memory Loss." Mercola.com. May 7, 2015. http://articles.mercola.com/sites/articles/archive/2015/05/07/sleep-apnea-memory-loss.aspx.
  3. "Sleep-disordered Breathing Advances Cognitive Decline in the Elderly." Neurology. April 15, 2015. http://www.neurology.org/content/early/2015/04/15/WNL.0000000000001566.
  4. Carroll, Linda. "Sleep Apnea May Speed Memory Loss, Alzheimer's Onset: Study." NBC News. April 16, 2015. http://www.nbcnews.com/health/health-news/sleep-apnea-linked-earlier-memory-loss-study-n342931.
  5. "Sleep Apnea and Heart Disease, Stroke." July 1, 2015. Accessed December 16, 2015. http://www.heart.org/HEARTORG/Conditions/More/MyHeartandStrokeNews/Sleep-Apnea-and-Heart-Disease-Stroke_UCM_441857_Article.jsp#.
  6. "Sleep Apnea & Snoring Treatment." I Hate CPAP! Accessed December 21, 2015. http://www.ihatecpap.com/cpap.html.