All about sleep-related breathing disorders?

According to estimates, around 1 billion people in the world are suspected of having the most common type of sleep-related breathing disorder, obstructive sleep apnoea (OSA). This is just one of the types of breathing problems that can occur during sleep. In this article, we’ll tell you all about the different conditions that can affect breathing during sleep. 

What are sleep-related breathing disorders?

Sleep-related breathing disorders include a range of conditions that interrupt normal breathing patterns during sleep. From mild snoring to more severe conditions like obstructive sleep apnoea (OSA), these disorders can have a profound impact on an individual’s quality of sleep and overall health and wellbeing. 

The most common sleep-related breathing disorders are:

• Snoring
• Obstructive sleep apnoea (OSA)
• Upper Airway Resistance Syndrome (UARS)
• Central sleep apnoea (CSA)
• Complex sleep apnoea syndrome
• Sleep-related hypoventilation disorders
• Sleep-related hypoxemia disorder
• Catathrenia

What causes sleep-related breathing disorders?

Sleep-related breathing disorders are caused by a variety of factors. Understanding the cause is crucial for preventing the conditions and for their management. The causes can be multifaceted and will likely involve a combination of genetic, anatomical, lifestyle and environmental factors. 

Here are some of the key contributors to sleep-related breathing disorders:

• Obesity: Excess weight, particularly in the neck region, can contribute to sleep disorders like OSA as it can obstruct the flow of air during sleep.
• Anatomical abnormalities: Structural differences in the upper airways like enlarged tonsils or adenoids, a deviated septum or a narrow throat can contribute to airway obstruction during sleep.
• Genetics: Individuals can have a genetic predisposition to sleep-related breathing disorders. Those with a family history are at a higher risk.
• Age: Ageing muscles lose tone, which can impact the integrity of the airway.
• Gender: Males are more susceptible to sleep-related breathing disorders.
• Alcohol consumption and smoking: Both smoking and excessive alcohol consumption can cause the relaxation of muscles in the throat. This increases the likelihood of airway obstructions and contributes to the existence of sleep-related breathing disorders.
• Existing medical conditions: Certain medical conditions like hypothyroidism and acromegaly growth differences can affect the respiratory system.
• Neuromuscular disorders: Conditions affecting the nerves and muscles involved in breathing can cause sleep-related breathing disorders. Examples include muscular dystrophy and myasthenia gravis.
• Sleep position: Sleeping in a certain position (on your back) can contribute to sleep-related breathing disorders and can play a role in the severity of an existing condition.

Types of sleep-related breathing disorders

There are several types of sleep disorders involving breathing difficulties. Some have limited impact on health while others have serious implications due to their potential effects on the body. It is also possible to be diagnosed with more than one type of sleep-related breathing disorder. 

Obstructive sleep apnoea (OSA)

This is the most common and one of the most serious sleep-related breathing disorders. With OSA, there are lapses in breathing due to the airway collapsing in sleep. This causes fragmented sleep and dips in blood oxygen levels.

Symptoms of OSA include gasping, choking and snoring during sleep. These are usually observed by partners or family members as the individual is generally unaware of these events. 

The individual will likely experience daytime sleepiness as a result of inadequate sleep. Untreated, this can lead to further issues like high blood pressure, stroke and cardiovascular disease. It can also impact on type 2 diabetes due to its promotion of insulin resistance caused by inadequate sleep.

Central sleep apnoea (CSA)

This is similar to OSA in its signs and symptoms but the cause is different. The lapses in breathing occur due to the brain’s messages about when to breathe being confused. This happens when the brain’s signals aren’t telling the muscles to breathe. It can also happen when the respiratory muscles don’t respond to the signals coming from the brain. This is much rarer that OSA. 

It is also possible to have both central sleep apnoea (CSA) and OSA. 

Risk factors for CSA include being at high altitude, using narcotics, cardiovascular problems and brain abnormalities like Chiari Malformation. 

Sleep-related hypoventilation disorders

These conditions involve high levels of carbon dioxide in the blood. This is a result of the lungs failing to rid themselves of enough air. 

People with insufficient breathing during sleep often have other conditions like pulmonary hypertension or Chronic Obstructive Pulmonary Disease (COPD). Nervous system problems can also cause this as can certain medicines.

Lots of people who have sleep-related hypoventilation disorders also find it difficult to breathe when they’re awake but this is intensified during sleep. 

Complex Sleep Apnoea Syndrome (CompSAS)

This is a type of sleep apnoea that combines both CSA and OSA. Sometimes, the central sleep apnoea can be brought on by using a CPAP machine for obstructive sleep apnoea. It is diagnosed when CPAP is in use and there are fewer than 5 obstructive events per hour but more than 5 central apnoea events. Over 80% of those with CompSAS are male. In these situations, many patients use BiPAP machines instead of CPAP machines as the fluctuating pressure is believed to help.

Sleep-related hypoxemia disorder

Hypoxemia means low blood oxygen. When this happens during sleep, it is usually caused by an existing health condition affecting the lungs. This is similar to sleep-related hypoventilation disorder but is milder in that the carbon dioxide levels don’t rise as high.

Snoring

Snoring is a common sleep-related breathing disorder. According to the British Snoring and Sleep Apnoea Association, 41.5% of the UK adult population snore; 58% of these are in their 50s. 

Snoring happens when air moves in the soft tissues of the upper airway. The movement of air causes these tissues to vibrate, which causes the sound. Occasional light snoring is normal and doesn’t cause harm. When snoring occurs at least three nights per week, it could be an indication that there is a more serious sleep-related breathing disorder. 

Snoring itself can be categorised as habitual, chronic or primary. This is different from the snoring associated with OSA.

Snoring is contributed to by a range of factors including:

• Nasal congestion
• Sleep positioning
• Obesity
• Alcohol consumption
• Use of medication and sedatives

Catathrenia

This is a sleep-related breathing disorder that is characterised by vocalisation and abnormal breathing. It involves breath holding (end-inspiratory apnoea) and expiratory groaning. 

This condition usually begins with a deep intake of breath. The individual will then hold their breath with a closed glottis (the opening between the vocal folds). The exhalation might either be simple and rapid or a slow movement with sound. Even though the breathing rate slows, there’s usually no problem with oxygen levels. The person themselves won’t hear their own noisy breathing but, like snoring, it is disruptive to bed partners.

Upper Airway Resistance Syndrome (UARS)

This is similar to OSA but the airway obstruction is not as pronounced. It is characterised by an increased resistance to airflow in the upper airway. This leads to disruptions in normal breathing patterns while the person is asleep. 

The impact of sleep-related breathing disorders

Sleep-related breathing disorders have an impact beyond disruptive sleep. The consequences of these problems can occur to health, wellbeing and quality of life. Here are some of the impacts seen:

Cardiovascular problems

Sleep-related breathing disorders, OSA in particular, are linked to hypertension. The pauses in breathing lead to higher blood pressure, which puts a strain on the heart and the whole cardiovascular system. Untreated sleep-related breathing disorders are also associated with other cardiovascular conditions like irregular heart rhythms and coronary artery disease.

Problems with daytime functioning

People with sleep-related conditions will often experience daytime sleepiness. This can impair functioning and productivity. It can have an impact on work, education and safety.

Poor sleep can also cause fatigue and irritability, which can affect personal and professional relationships too. 

Effects on the metabolism and endocrine system

Sleep-related breathing disorders have been linked to insulin resistance and an increased risk of type 2 diabetes. It is believed that the physiological stress induced by these disorders disrupts the metabolism of glucose. 

Weight gain is also common with sleep-related breathing disorders—and it, in turn, worsens the conditions too. 

Neurocognitive problems

Poor quality sleep and disturbances are known to impair memory consolidation. They also affect the ability to concentrate, which impedes daily functioning and learning. There is also an increased risk of cognitive decline in older adults.

Quality of life

The cumulative impact of the physical and cognitive consequences of a sleep-related breathing disorder can significantly diminish an individual’s overall quality of life. It can affect work performance, hobbies, relationships and overall wellbeing.

Mental health

Naturally, poor sleep is associated with a higher prevalence of mood disorders like depression and anxiety. It also means that people have a lower tolerance for stress. 

Treatment for sleep-related breathing disorders

The treatment options for sleep-related breathing disorders vary depending on the specific type and severity of the disorder. Here are several common approaches:

Lifestyle modifications

Modifications to your lifestyle can help alleviate the symptoms of some sleep-related breathing disorders, particularly the milder ones:

• Weight management: For individuals whose sleep apnoea is contributed to by obesity, weight loss can significantly improve symptoms. Adopting a healthy diet and incorporating regular exercise can contribute to weight management.
• Sleep positional therapy: Changing sleep positions, such as avoiding sleeping on the back, may be recommended to alleviate symptoms, especially in individuals with positional obstructive sleep apnoea.
• Avoidance of alcohol and sedatives: Steering clear of alcohol and sedative medications, especially before bedtime, can help reduce the relaxation of the muscles in the throat. This decreases the likelihood of airway obstruction.

Continuous Positive Airway Pressure (CPAP) therapy

CPAP is a common and highly effective treatment for obstructive sleep apnoea. It involves wearing a mask over the nose or nose and mouth during sleep. The machine delivers a continuous stream of air to keep the airway open, even during exhalation. This can be difficult to get used to but it is a positive solution for many people with OSA.

Bi-level Positive Airway Pressure (BiPAP) therapy

This is similar to CPAP. The difference is that the machine delivers air at a different pressure for exhalation compared to inhalation. 

Oral devices

Oral devices are custom-fitted and are like mouthguards. They reposition the tongue and lower jaw to help keep the airway open. They are often used for mild to moderate obstructive sleep apnoea or for individuals who cannot tolerate CPAP.

Surgery

Sometimes, surgical interventions can cure sleep-related breathing disorders that are caused by anatomical abnormalities. Procedures include: 

• Uvulopalatopharyngoplasty (UPPP): This is a surgical procedure that removes and repositions tissue in the airways to stop it from collapsing during sleep. It is used for patients with obstructive sleep apnoea.
• Genioglossus advancement (GA): This is a surgical procedure that pulls forward the base of the tongue to increase the size of the airway. It is often performed with other surgeries like UPPP and MMA.
• Maxillomandibular advancement (MMA): This is a type of jaw surgery. It is sometimes called Bi-Max (bimaxillary advancement) or MMO (maxillomandibular osteotomy). This is a procedure that moves the upper and lower jaws forward to create more space in the airways.

Adaptive Servo-Ventilation (ASV)

This is a therapy that delivers pressurised air in a similar manner to CPAP. This is used more commonly with central sleep apnoea as it responds to variations in breathing patterns. 

Inspire therapy

This is an implantable device that stimulates the hypoglossal nerve. This prevents the airway from collapsing during sleep. Inspire therapy is usually considered for individuals who have moderate to severe obstructive sleep apnoea who don’t get along with CPAP or BiPAP.

Positional therapy devices

These are designed to prevent people from sleeping on their backs. They reduce the severity of symptoms from obstructive sleep apnoea. They are recommended for mild cases. 

Final thoughts on sleep-related breathing disorders

In conclusion, sleep-related breathing disorders have a profound impact on the health and wellbeing of those with the conditions. The ramifications of untreated conditions are far and wide as they impact on serious issues such as cardiovascular health and metabolic function right down to relationships with bed partners.

Getting appropriate treatment and support for sleep-related breathing disorders is crucial. The choice of treatment depends on factors such as the type and severity of the sleep-related breathing disorder, individual preferences, and the presence of underlying health conditions. Individuals experiencing symptoms should consult with a healthcare professional or sleep specialist to seek a diagnosis and determine the most suitable treatment plan for their specific case. With appropriate treatment, those with sleep-related breathing disorders can drastically improve their lives.