Sleep apnea is manifested by involuntary stops in breathing, “apnea”, which occurs during sleep. Sleep apnea usually occurs in people who are overweight, elderly, or who snore heavily.
These respiratory pauses last by definition more than 10 seconds (and can reach more than 30 seconds). They occur several times a night, with varying frequency. Doctors consider them problematic when there are more than 5 per hour. In severe cases, they occur up to more than 30 times per hour.
These apneas disrupt sleep and mainly result in fatigue upon waking, headaches or drowsiness during the day.
While the majority of people with sleep apnea snore loudly, snoring should not be confused with apnea. Snoring is not considered a health problem in itself and is rarely accompanied by pauses in breathing. Researchers estimate that 30% to 45% of adults are regular snorers.
Causes of sleep apnea
In the majority of cases, apneas are due to a relaxation of the tongue and muscles in the throat, which are not toned enough and block the passage of air during breathing. Thus, the person tries to breathe, but the air does not circulate because of the obstruction in the airways. This is why doctors talk about obstructive apnea, or obstructive sleep apnea syndrome (OSAS). This excessive relaxation mainly concerns the elderly, whose muscles are less toned. Obese people are also more prone to sleep apnea because excess neck fat decreases the size of the airways.
More rarely, apneas are caused by a malfunction of the brain, which stops sending the “command” to breathe to the respiratory muscles. In this case, unlike obstructive apnea, the person does not make a breathing effort. This is called central sleep apnea. This type of apnea occurs mostly in people with a serious condition, such as heart disease (heart failure) or neurological disease (eg meningitis, Parkinson’s disease…). They can also appear after a stroke or in severe obesity. The use of sleeping pills, narcotics or alcohol is also a risk factor.
Many people have “mixed” sleep apnea, with alternating obstructive and central apnea.
Prevalence of sleep apnea
The frequency of sleep apnea is very high: it is comparable to that of other chronic diseases such as asthma or type 2 diabetes. Sleep apnea can affect adults and children, but its frequency increases strongly with age.
It is 2 to 4 times more common in men than in women, before the age of 60. After this age, the frequency is the same in both sexes.
The estimate of the prevalence varies depending on the degree of severity taken into account (number of apneas per hour, measured by the apnea-hypopnea index or AHI). Some studies in North America estimate the frequency of obstructive sleep apnea (more than 5 apneas per hour) at 24% in men and 9% in women. About 9% of men and 4% of women are thought to have a moderate to severe form of obstructive sleep apnea syndrome.
In the short term, sleep apnea causes fatigue, headaches, irritability… It can also upset a spouse, as it is often accompanied by loud snoring.
In the long term, if left untreated, sleep apnea has many health consequences:
- Cardiovascular illnesses: Sleep apnea significantly increases the risk of cardiovascular disease, through mechanisms that are not fully understood. However, we know that each pause in breathing causes a deficiency in oxygenation of the brain (hypoxia), and that each sudden micro-awakening causes an increase in blood pressure and heart rate. In the long term, apneas are associated with an increased risk of cardiovascular problems, such as: hypertension, stroke, myocardial infarction (heart attack), heart rhythm disturbances (cardiac arrhythmia) and heart failure. Finally, in the event of significant apnea, the risk of dying suddenly while sleeping is also higher.
- Depression: Lack of sleep, fatigue, the need to take naps, and drowsiness are associated with sleep apnea. They decrease the quality of life of those affected, who often suffer from depression and isolation. A recent study even showed a link between sleep apnea and cognitive impairment in older women.
- Accidents: Lack of sleep induced by apnea increases the risk of accidents, especially accidents at work and on the road. People with obstructive sleep apnea syndrome are 2 to 7 times more likely to be in a traffic accident.
- Complications in case of surgery. Sleep apnea, especially if it has not yet been diagnosed, can be a risk factor for general anesthesia. Indeed, anesthetics can accentuate the relaxation of throat muscles and therefore worsen apnea. Pain medication given after surgery can also increase the risk of severe apnea. It is therefore important to tell your surgeon if you have sleep apnea.
When to consult a doctor
Doctors believe that the vast majority of people with sleep apnea don’t know it. Most often, it is the spouse who notices the presence of apnea and snoring. It is advisable to consult a doctor if:
- your snoring is loud and disturbs your partner’s sleep;
- you often wake up at night feeling like you are struggling to breathe or if you use the bathroom several times a night;
- your partner notices breathing stops while you sleep;
- you feel tired in the morning and you fall asleep frequently during the day.
Your doctor may refer you to a center specializing in the study of sleep. In this case, a test called polysomnography will be done. This test allows specialists to study the different phases of sleep and to measure several parameters to detect sleep apnea and assess their severity. In practice, you have to spend one night in a hospital or in a specialized center. Electrodes are placed in different places on the body to observe parameters such as brain or muscle activity, the level of oxygen in the blood (to ensure that breathing is efficient) and the different phases of sleep. This helps to know if the person is able to enter a deep sleep phase or if apneas prevent it.
Symptoms of sleep apnea
Usually, people with sleep apnea don’t notice that they take breathing pauses at night. However, apneas cause “micro-awakenings” which alter the quality of sleep. The most common symptoms are therefore those resulting from fragmented and poor quality sleep.
- Significant fatigue during the day and upon waking up;
- Frequent and uncontrolled drowsiness and falling asleep (watching television, at work, driving, etc.);
- Heavy snoring;
- Headaches when you wake up;
- Irritability, a feeling of depression;
- Memory impairment;
- A drop in school results among the children concerned;
- A feeling of suffocation or suffocation at night.
People at risk of sleep apnea
Several factors increase the risk of sleep apnea:
- Obesity: This is the main risk factor for obstructive sleep apnea, especially because excess fat in the neck causes narrowing of the airways. Obesity increases the risk of sleep apnea by about 7 times;
- Age: The frequency of sleep apnea syndrome doubles or triples after the age of 65;
- Sex: Men are 2 to 3 times more affected than women;
- Ethnic origin: African Americans and Asians have a higher risk of sleep apnea2;
- Certain abnormalities of the airways or jaws: In some people, the airways are too narrow or the tonsils (glands in the back of the throat) are too large and obstruct the passage of air. This is often the case in children with obstructive sleep apnea syndrome. An abnormality of the jaws can also make it more difficult for air to pass through. These abnormalities can be accompanied by snoring;
- Genetic factors: In some families, obstructive sleep apnea syndrome is very common, due to genetic susceptibility. The risk of suffering from sleep apnea is multiplied by 2 to 4 in close relatives of a person with obstructive sleep apnea syndrome;
- The circumference of the neck: The wider the neck (more than 43 cm or 17 inches in circumference in men, more than 40 cm or 16 inches in women), the greater the risk of apnea.
- Nasal obstruction: People who often have a stuffy nose, for example due to allergies, are more prone to sleep apnea;
- Alcohol consumption: Alcohol causes the muscles in the throat to relax, which increases the frequency and duration of sleep apnea;
- Some medications, such as sleeping pills, muscle relaxers, or anti-anxiety medications, make apnea worse for the same reasons as alcohol;
- Smoking: Smoking increases the risk of obstructive sleep apnea syndrome, possibly because it causes inflammation of the airways. Smokers are 2.5 times more likely to suffer from sleep apnea than non-smokers;
- Type 2 diabetes: Type 2 diabetes is associated with a high risk of sleep apnea, for reasons that are still poorly understood, but often related to obesity. In diabetics, the prevalence of obstructive sleep apnea syndrome can reach 23%.
How to prevent sleep apnea
As obesity is the main risk factor for sleep apnea, maintaining a healthy weight by eating a balanced diet and participating in regular physical activity is an effective preventive measure.
The fight against diabetes also reduces the risk of obstructive sleep apnea. Finally, if you have high blood pressure, it is important to take your medication regularly to reduce your overall risk of cardiovascular disease.
Measures to prevent aggravation
If you suffer from sleep apnea, you can improve the quality of your sleep and reduce your symptoms by taking simple healthy lifestyle measures. These measures sometimes make it possible to make apneas disappear in mild cases:
- Losing weight. If you are overweight, losing a few pounds is often enough to improve the quality of your sleep. Thus, a loss of 10% in weight reduces the severity (frequency and duration) of apneas by 26%;
- Sleep on your side. For anatomical reasons, the narrowing of the airways is greatest when you sleep on your back. Sleeping on your side often helps reduce sleep apnea. There are special pajamas (with a ball sewn into the back) that prevent the sleeper from rolling onto his or her back at night;
- Raise the bed. You can elevate the head of the bed a few inches, so that your neck and torso are tilted slightly at night (for example, by putting wedges under the legs of the bed). This facilitates the opening of the airways and can be effective in cases of mild apnea;
- Avoid sleeping pills and alcohol. When sleeping poorly, it is tempting to resort to sleeping pills. However, these increase the relaxation of the muscles of the throat and tongue and have the consequence of worsening apneas. Likewise, alcohol should be consumed in moderation;
- Stop smoking. Smoking worsens apnea by creating inflammation in the airways and relaxation of the muscles that keep these airways open. In addition, tobacco increases the risk of cardiovascular problems. It is therefore essential to stop smoking. Do not hesitate to ask your doctor for help;
- Treat your allergies. Nasal congestion interferes with breathing and makes snoring and sleep apnea worse. If you have recurring allergies, talk to your doctor to find a suitable treatment. However, be careful with antihistamine drugs, which have a sedative effect and can worsen apnea.
Measures to prevent complications
Sleep apnea is a potentially serious condition that must be taken seriously. In addition to trying to lose a few pounds if you are overweight, it is important that you follow your doctor’s directions and wear your breathing mask every night.
To reduce the risk of cardiovascular complications, also practice regular physical activity and follow your treatments for high blood pressure or diabetes.
To date, there are no drugs available to treat sleep apnea. However, very effective mechanical treatments exist:
- Continuous positive airway pressure (CPAP). It is the treatment of choice for sleep apnea. A device continuously blows air through the nose, using a mask worn at night. Several models of devices and masks are available. The blown air keeps the airways continuously open, which suppresses apnea. Although this treatment is extremely effective, it takes time to get used to sleeping with the mask on. It may seem uncomfortable at first, but you have to be patient. The reduction in symptoms is felt after 4 to 6 weeks, if the mask is worn every night. This treatment improves the quality of life, alertness and memory of those affected, as well as lowering blood pressure in associated hypertension;
- Oral apparatus. This is a dentist molded splint that is worn at night, also called a mandibular advancement splint. It keeps the lower jaw and the tongue forward (a few millimeters), making it easier to pass air. These devices are especially reserved for people with mild or moderate apnea. They are less effective than continuous positive pressure ventilation, but require less adaptation effort.
Although there are no medications that can suppress sleep apnea, some treatments can help reduce apnea by treating the cause.
So, if the apneas are due to allergic rhinitis, nasal corticosteroids can reduce the number of apneas. Likewise, in patients with gastroesophageal reflux disease which can make apnea worse, taking an anti-reflux medicine (such as omeprazole) helps reduce apnea.
Finally, if the drowsiness is very important during the day despite treatment with CPAP, stimulant drugs may possibly be prescribed. Talk to your doctor.
In some cases, when CPAP ventilation therapy does not work or is not well tolerated, surgery may be considered.
There are several types of operations designed to reduce snoring and breathlessness. However, their effectiveness is relatively low and apneas tend to recur some time after the procedure. There is not enough evidence to recommend these interventions for people with mild to moderate sleep apnea.
- Uvulo-palato-pharyngoplasty (UPPP). This operation involves removing the uvula and part of the soft palate, which vibrate during snoring, so as to clear the airways and facilitate the passage of air. It is performed under general anesthesia. It is effective in reducing snoring, but does not prevent the throat from sagging. It is only effective on apnea in 50% of cases;
- Tonsillectomy and adenoidectomy. These procedures involve the surgical removal of tonsils and adenoids, lymph nodes located in the throat. If they are very swollen, which often happens in children, they can obstruct the passage of air and cause apnea. This operation is mainly offered in cases of obstructive sleep apnea syndrome in children;
- Nose and sinus surgery. It is useful if the apneas are related to an abnormality of the nasal septum or the sinuses which interferes with breathing;
- Tracheotomy. This “radical” operation is reserved for people with very severe apnea and for whom CPAP ventilation is not effective. It is therefore very rarely offered. It consists of creating an opening in the trachea, below the throat. This “hole” allows air to enter the lungs without passing through the throat at night. It can be blocked during the day to resume normal breathing;
- Surgery for weight loss. When sleep apnea is due to severe obesity, losing weight can act effectively on apnea. Bariatric surgery, reserved for severe obesity, can reduce the severity of apnea.
Mandell is currently working towards a medical degree from the University of Central Florida. His main passions include kayaking, playing soccer and tasting good food. He covers mostly science, health and environmental stories for the Scientific Origin.