Sleep apnoea is a medical disorder of varying clinical severity, which results from an involuntary cessation of breathing for a short time during sleep. Usually, this is a consequence of the muscles of the throat being completely relaxed and ‘obstructing’ or blocking the airway. The most common type of sleep apnoea is commonly referred to as obstructive sleep apnoea (OSA).
Sleep apnoea can lead to many complications if not diagnosed and treated in time. I have tried to list below some of the most common complications of untreated obstructive sleep apnoea that I see in the clinic.
Complications of untreated OSA
Respiratory:
- In severe cases (especially with co-existing respiratory disease), the low oxygen reaching the lungs can lead to changes in the blood vessels. This is called ‘hypoxic pulmonary vasoconstriction’ or simply narrowing of the blood vessels, raised pressures and eventually, heart failure.
- It can also cause red blood cells (a type of cell found in human blood carrying haemoglobin) to stick to each other in the vessels and cause a disease called ‘polycythaemia’, which can lead to life-threatening problems such as pulmonary embolisms – a blockage in the blood vessel that carries blood from the heart to the lungs; deep vein thrombosis (DVT) – a blockage that forms in the blood vessels in your leg before moving elsewhere in your body.
- OSA can also affect airway immunity, leading to an increased occurrence of respiratory tract infections and asthma-like exacerbations.
Cardiovascular:
- Multiple arousals lead to a raised arterial blood pressure. The blood pressure tends to surge with arousal.
- Those who suffer from OSA experience drops in blood oxygen levels due to breathing pauses. This prevents enough oxygen from circulating around the body. The drop in blood oxygen puts added pressure on the cardiovascular system and increases the release of stress hormones. Slowed and interrupted breathing whilst asleep alerts the brain to send signals to increase blood pressure and heart rate in an attempt to increase oxygen getting to the body’s tissues.
- This increases the risk of these patients to cardiovascular and cerebrovascular events such as strokes and myocardial infarctions.
- The risk of cardiovascular disease is increased even with mild OSAS.
- If the patient has atrial fibrillation (AF, an irregular heart rhythm), sleep apnoea can trigger episodes of AF. This can potentially lead to disastrous emergency hospital admissions due to failure of the heart to support circulation and sudden cardiac deaths.
Endocrine/Hormonal:
- OSA, hypertension, obesity, and insulin resistance share a complex relationship in which all four factors influence and exacerbate one another.
- Obesity predisposes people to OSA.
- Research suggests that when a person has both OSA and excess weight, the two conditions may affect one another in ways that impair cardiovascular health.
- OSA and obesity both cause elevated levels of leptin in the blood. Leptin is a hormone that promotes hunger, which can further contribute to weight gain.
- People with insulin resistance require sweepingly higher levels of the hormone insulin to be able to use the ‘sugar’ in the blood for energy. Over time, insulin resistance can result in uncontrolled glucose levels in the blood and the development of diabetes. Recent studies have shown that OSA is also a cause of insulin resistance, irrespective of the weight involved.
- Variable degrees of reproductive organ dysfunction are associated with OSA. This impairment is linked to hypoxia and disordered breathing, independent of increasing age or obesity.
Neurocognitive:
- Due to the fragmented and poor sleep quality, patients may suffer from daytime drowsiness, slow reactions, poor memory and concentration, irritability, and a reduced quality of life.
- Daytime sleepiness is a major cause of road traffic accidents. Patients with untreated OSA are 7-20 times more likely to be involved in an accident.
- Untreated OSA can cause a person to have mood swings. Over time, these mood swings can worsen and develop into major episodes of depression. Those who suffer from depression or anxiety usually have problems sleeping; insomnia is one of the common symptoms of depression.
- In older people, the incidence of OSA and depression are both higher.
- Individuals with eating disorders, especially binge eating disorder (BED), are more prone to obesity and OSA.
Miscellaneous:
- Sleep-deprived partners: Loud snoring can keep anyone who sleeps nearby from getting good rest. It’s common for a partner to go to another room to be able to sleep.
Sleep apnoea treatments
- Mandibular advancement devices protrude the mandible, opening the airway behind the tongue. Treatment with these devices is safe, producing common but transitory and mild side effects such as excessive salivation, dry mouth and gum irritation. They can also cause temporary jaw joint dysfunction. Although a good success rate has been reported after an accurate selection of the patients, it has to be mentioned that up to one-third of the patients are unresponsive to this modality.
It is useful where CPAP (see below) is poorly tolerated.
- Another group of oral appliances include tongue-retaining devices. These are newer devices designed to produce a gentle suction of the tongue into an anterior bulb to move the tongue forward and increase the upper airway dimensions during sleep. Overnight application of these devices significantly reduces snoring and has shown similar efficacy compared with other orthodontic devices. Although promising, there is still insufficient evidence to recommend using these oral appliances in clinical practice.
- Continuous Positive Airway Pressure (CPAP) is the ‘gold’ standard treatment option. This involves going to bed wearing a mask that is connected to a small machine, which blows pressurised air into the upper airway and prevents the airway from narrowing. The airway is splinted pneumatically with pressures of 7-15 cm H2O. Intelligent machines adjust the pressure to maintain airflow and are effective within a few hours of use.
Symptoms are improved within 2-3 days as the sleepiness resolves and the oedema in the soft palate resolves. After 2-3 weeks, the brain’s sleep function also improves.
- Surgery: As airway obstruction can occur at different sites, diverse levels of surgery exist, including minimally invasive techniques (under local anaesthesia as an outpatient procedure) and more invasive procedures. Surgery can be performed on the nose, oropharynx tract, tongue, or craniofacial structures to help treat OSA.
- Educational and behavioural interventions
- These represent the first step in approaching patients with OSA, independently from the treatment chosen. Patients should be instructed to avoid risk factors such as smoking, drinking alcohol (particularly in the evening), and using sedatives and hypnotics in their routine usage.
- It is imperative that patients understand the role that obesity plays in their disorder and provide advice to maintain an optimal weight.
- Intensive lifestyle interventions are effective in managing OSA, resulting in significant weight loss and reduced sleep apnoea severity.
- Another goal of the educational approach is to help each patient recognise the need for regular use of nocturnal CPAP. If the patient complies with the CPAP, he/she will notice improved sleep and quality of life.
- Miscellaneous interventions and positional therapy
- Good sleeping habits and sleep patterns are important to feeling well and happy and supplement the holistic treatment of OSA.
- Patients should try to go to bed and get up at the same time every day. This helps the brain and internal body clock get used to a routine.
- Most adults need between six and nine hours of sleep a night.
- If you sleep on your back, try sleeping on your side to relieve your symptoms. Due to anatomical and physiological mechanisms, the body’s position during sleep influences the frequency and severity of obstructive events. The supine position, mainly due to the effect of gravity on the tongue and soft palate position, is generally associated with an increased number of apnoeas/hypopnoeas.
Worried you may have OSA?
Sleep apnoea can profoundly affect physical and mental well-being in many ways. It is important to contact your GP and the right specialists if you are struggling with your sleep or breathing. In severe cases, sleep apnoea can also lead to life-threatening conditions. It is important to ensure that the correct type is diagnosed as soon as possible to start the right treatment.
OSA can significantly impact the quality of life for someone with the condition, as well as their friends and families. For support and advice about living with OSA, you may find it helpful to contact a support group, such as the British Lung Foundation and Sleep Apnoea Trust.
As a leading sleep and respiratory physician specialising in sleep apnoea and sleep-related breathing disorders, I offer consultations to diagnose and treat these conditions. Please contact me if you have any further queries about sleep apnoea complications or want further advice on the potential treatments available.
