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Though obstructive sleep apnoea (OSA) is relatively common, it is difficult to find statistics on the number of people affected by the condition. However, research suggests that around 1 million people in the UK have been prescribed treatment for obstructive sleep apnoea (in the form of a Continuous Positive Airway Pressure (CPAP) device) over the last 30 years.
In general, it is believed that around 4% of men in middle age and 2% of women in middle age have OSA. It is believed that there are around 6 million people with a mild version of OSA and a further 4 million with moderate or severe OSA.
What is obstructive sleep apnoea?
Obstructive sleep apnoea (OSA) is a sleep disorder characterised by periods of shallow breathing or pauses in breathing during sleep. Pauses occur regularly throughout the night lasting between seconds and even minutes.
OSA is the most common type of sleep apnoea and is caused by a narrower upper airway. When you have OSA, you don’t sleep properly because your snoring and breathing problems disrupt things. As a result, people with the condition often feel sleepy during the day and might even fall asleep while driving or working.
The condition is relatively common but occurs more frequently after age 50 and is more common in men than women.
What causes obstructive sleep apnoea?
Obstructive sleep apnoea is caused by the throat narrowing excessively during sleep. The cause of the narrowing can be many things. These include:
- Poor muscle tone when asleep. The muscles in the throat and tongue play an important role in keeping the airway open while you sleep. If these relax too much, they will collapse and obstruct the airway.
- Obesity: Having excess body weight, particularly around the neck, can contribute to airway narrowing and sleep apnoea.
- Upper airway anatomy: Some anatomical features can increase the likelihood of airway obstruction. If you have a thick neck, a large tongue, a naturally narrow airway, enlarged tonsils or adenoids, for example, you might be naturally more prone to developing sleep apnoea.
- Age: OSA is more likely to occur in older adults. This is because muscles lose elasticity and tone as you age.
- Gender: Men are more likely to develop the condition. However, post-menopausal women have an increased risk compared to premenopausal women, which suggests that hormones play a role.
- Family history: There may be a genetic component to your likelihood of developing sleep apnoea. If you have an immediate family member with the condition, you’re more likely to get it yourself.
- Using alcohol or sedatives: Alcohol consumption and sedative medications can relax muscles and increase OSA.
- Smoking: This can cause inflammation and fluid retention, which contributes to obstructive sleep apnoea.
The signs of obstructive sleep apnoea
There are a range of signs and symptoms of sleep apnoea but many of them are first apparent to a family member or partner. These are:
- Noisy and loud snoring: This is the hallmark symptom. The snoring is disruptive.
- Laboured or loud breathing.
- Periods of breathing that are interrupted by snorting or gasps: There are pauses in breathing often witnessed by partners. The pauses last from seconds to minutes. These may be followed by choking or gasping sounds as breathing resumes.
- Restless sleep: Tossing and turning is common as the body is responding to interrupted breathing.
- Extreme mood swings or depression: Changes in temperament are common due to lack of good sleep.
- Sleepiness during waking hours: Persistent and excessive daytime sleepiness can cause problems with daily activities.
- Headaches on waking: Waking up with a headache is often a symptom of obstructive sleep apnoea. This is caused by fluctuating oxygen levels during the night.
- Poor work performance.
- Falling asleep while eating, driving and working.
- Frequent nighttime urination: Nocturia, or the need to urinate frequently during the night, is often associated with obstructive sleep apnoea.
- Decreased libido: A decrease in sex drive is linked to OSA due to its impact on energy levels and wellbeing.
- Dry mouth or sore throat: This is often a symptom due to mouth breathing during periods of airway obstruction.
- Difficulty falling asleep: Some people with obstructive sleep apnoea find it hard to fall asleep initially.
Diagnosing obstructive sleep apnoea
Many families joke about someone being a snorer but if the snoring is excessive and is causing excessive daytime sleepiness, it is probably worth going to the GP to see if obstructive sleep apnoea is occurring.
The Epworth Sleepiness Scale
This measures how sleepy you are during the day. Individuals answer a few questions about how likely they would be to doze off in a set number of situations on a scale of 0 to 3 with 0 being ‘would never doze’ and 3 being a ‘high chance of dozing’. The situations asked about are activities like sitting and reading, watching TV, being in a meeting, being in a car, for example. Scoring high on this test indicates the presence of one or more sleep disorders.
The Stop Bang Questionnaire
This is a series of yes or no answers that points to the likelihood of you having OSA. You’re asked things like whether you snore loudly, whether your BMI is over 35, and whether your neck circumference is greater than 40 cm, for example. The number of ‘yes’ answers converts to a score, which determines your risk (low, medium, high) of having OSA.
Getting a diagnosis
If sleep apnoea is suspected, a GP will refer you for tests to a specialist sleep clinic. The clinic may give you devices to wear during sleep to record your breathing and heart rate. This can usually be done at home but some individuals will need to stay in a sleep clinic to be monitored overnight.
The test shows if you are suffering from sleep apnoea and, if you are, it will determine how severe it is. The test will give you a number on the Apnoea-Hypopnoea Index (AHI). This counts the number of apnoeas and hypopnoeas during sleep. Apnoeas are when breathing stops; hypopnoeas are when the airflow is constricted and so breathing is shallow.
A normal AHI is five events or fewer per hour of sleep. Severe AHI is 30+.
Here are the ranges of severity:
- Mild OSA: between 5 and 14 events per hour.
- Moderate OSA: between 15 and 29 events per hour.
- Severe OSA: Over 30 events per hour.
The impact of obstructive sleep apnoea
OSA can have a significant impact on physical and mental health. Untreated, it can lead to complications and other conditions.
Here are some of the main impacts observed:
Daytime sleepiness and fatigue
The repeated interruptions in breathing at night cause fragmented sleep, which results in poor quality sleep and excessive daytime sleepiness. This means that individuals may struggle to stay alert and awake during the day. In turn, concentrating might be difficult when performing daily activities.
Impaired cognitive function
OSA can impact your ability to function and think. You might develop problems with attention, problem-solving and memory. This cognitive impairment is caused by intermittent drops in oxygen levels and poor quality sleep.
OSA is a risk factor for cardiovascular disease, hypertension, stroke and heart failure. This is due to the drop in oxygen causing strain on the cardiovascular system over time. High blood pressure is one of the main comorbidities of OSA. Arrhythmias are also common in OSA, particularly arterial fibrillation.
Metabolic syndrome and diabetes
Metabolic syndrome (pre-diabetes) is common in those with OSA. It is believed that OSA plays a role in insulin resistance due to oxygen shortage and sleep loss. There is also an increased risk of Type 2 diabetes.
Decreased quality of life
The combination of impaired cognitive function with daytime sleepiness as well as potential mood issues can lead to a decrease in quality of life for those with untreated OSA. It can impact work performance, hobbies and relationships.
Increased risk of accidents
Those with untreated OSA have an increased risk of accidents, including driving accidents.
The impact of OSA on relationships
With obstructive sleep apnoea, although being a health concern in its own right, its influence often extends beyond the individual. It can impact on personal relationships, especially when people share a bed with someone.
Loud snoring is one of the most disruptive factors of OSA. This can be a nightmare for bed partners and can cause a strain on the emotional closeness.
The daytime sleepiness or irritability can also have an impact on relationships too as it can lead to mood swings and arguments.
Treatment for sleep-related breathing disorders
The most effective way of treating OSA is with a CPAP machine. CPAP stands for Continuous Positive Airway Pressure. It is a small pump with a mask that is worn overnight. The machine delivers pressurised air, even when exhaling. This prevents the airways from collapsing. The devices, although cumbersome to wear and difficult to get used to, greatly improve sleep quality and reduce daytime sleepiness. It can be difficult to get used to breathing out against a constant flow of air but the benefits are worth it.
CPAP is given for severe cases of OSA. Other treatments may also be prescribed. These include:
- Oral appliances: This includes Mandibular Advancement Devices (MADs), which are dental devices that reposition the tongue and lower jaw to keep airways open.
- BiPAP (Bi-level Positive Airway Pressure): This is similar to CPAP but has different levels of air pressure for inhalation and exhalation.
- Surgery: Several surgeries can help. The surgery required depends on the cause of the condition. Here are some common surgeries:
– Uvulopalatopharyngoplasty (UPPP): This removes excess tissue in the throat to widen your airway.
– Genioglossus Advancement (GA): This repositions the tongue muscle attachment to prevent it from causing airway collapses.
– Maxillomandibular Advancement (MMA): This repositions the lower and upper jaws to enlarge the airway.
– Inspire Therapy: This implants a device to stimulate the hypoglossal nerve to prevent the airways from collapsing during sleep.
- Treating underlying conditions: If there are medical conditions that contribute to OSA like nasal congestion, allergies or hyperthyroidism, these should be treated.
- Lifestyle changes: This includes weight management and changing the position for sleeping.
Risk factors for OSA
Obstructive sleep apnoea (OSA) is influenced by various factors that can increase an individual’s susceptibility to this sleep disorder. Recognising these risk factors is crucial for early identification and intervention. Here are key elements to consider:
Smoking is a significant risk factor for the development and worsening of obstructive sleep apnoea. The harmful substances in tobacco smoke can lead to inflammation and fluid retention in the airways, contributing to airway obstruction during sleep. When individuals who smoke do quit, it is not only beneficial for their overall health but it can also mitigate the impact of OSA.
A sedentary lifestyle—one that is characterised by minimal physical activity and prolonged periods of inactivity—is associated with an increased risk of developing OSA. Regular exercise has been shown to improve muscle tone. This includes the muscles in the neck, which helps to maintain an open airway.
Certain medical conditions like hypothyroidism can contribute to OSA. Those with underlying medical conditions or other conditions that affect the endocrine system can increase their chances of developing OSA.
Final thoughts on obstructive sleep apnoea
Receiving a diagnosis of OSA can be life-changing for both the individual and their loved ones who are disrupted by the condition. Often, patients don’t realise the impact that the condition is having on them until they receive treatment like a CPAP machine and start to feel refreshed after sleep again. For the best management of the condition, it’s important to look at lifestyle factors too, especially obesity and being overweight, as these can cause comorbid conditions and worsen OSA.