Sleep Apnea: Causes, Symptoms and Treatment

In sleep apnea, patients suffer from multiple breathing interruptions during sleep. Here you can find out how the syndrome develops and what helps against it.

What is sleep apnea?

In sleep apnea, those affected have recurrent, nocturnal breathing stops during sleep. In many cases, severe snoring is one of the symptoms. In most cases, the patient himself does not even notice the sleep apnoea – it is rather the partners who notice the individual breathing stops, as these usually last between ten and 30 seconds. As sleep apnoea can lead to secondary diseases such as high blood pressure and, above all, makes the patient tired, it should definitely be treated, for example with a special breathing mask that is worn at night.

How dangerous is sleep apnea syndrome?

Faltering breathing always triggers an alarm signal in the brain and also in the body. This is what happens:

• Heart rate is increased
• Blood pressure is raised
• Vegetative nervous system is activated

In the case of high blood pressure, and especially high blood pressure at night, it should always be checked whether sleep apnea is present so that it can be treated. Because the otherwise permanently high blood pressure can trigger secondary diseases such as stroke or heart attack, as Prof. Ingo Fietze, head of the Interdisciplinary Sleep Medicine Center, specialist for internal medicine, pulmonology and somnology at the Charité Berlin confirms: “The breathing stops put a strain on the cardiovascular system, and the nightly oxygen depletion puts a strain on the brain. Long-term consequences are high blood pressure, cardiac arrhythmia, diabetes, dementia and other diseases.

The following common symptoms can also occur due to poor sleep:

• Reduced performance
• Concentration disorders
• Persistent fatigue, which also favours occasional nodding off. In road traffic, for example, this can be extremely dangerous.

Causes and risk factors: Obstructive and central sleep apnea

In medicine, a distinction is made between two different forms of sleep apnea, which also describe the main causes:

1. Obstructive sleep apnea

Obstructive sleep apnea is the more common of the two forms and occurs when the upper airways collapse at night. There is a cause for this and various provocative circumstances: the cause is a malfunction of the nerves that control/activate the muscles in the throat at night. Provoking factors are:

• Overweight: Obesity is one of the risk factors for sleep apnea – the disease is widespread among overweight people. “Obesity provokes snoring and respiratory disorders due to small fat deposits in the throat and due to the increasing circumference of the neck, but is usually not the sole cause,” explains Prof. Fietze.
• Supine position: If the muscles in the throat are flaccid, so is the base of the tongue. In the supine position the tongue therefore plays a decisive role in the temporary obstruction of the airway.
• Excessive muscle relaxation: Certain stimulants such as medication, cigarettes, drugs or alcohol can increase muscle relaxation and thus promote sleep apnea.
• Anatomy: Anatomical peculiarities such as a strongly receding lower jaw or extremely enlarged tonsils increase the breathing resistance and narrow the pharynx.

Once the respiratory tract is narrowed, the respiratory muscles continue to receive commands from the brain to take a breath. However, the muscles are not strong enough to transport air through the closed airways. This creates a pause for breath – and the body lacks oxygen for that moment. This in turn reduces the oxygen content in the blood, and carbon dioxide accumulates in the blood, tissue and brain. In the latter, an alarm is automatically triggered. The body immediately increases its activity by means of a wake-up stimulus, which leads to the body suddenly being able to take a breath again. In this way, the oxygen supply of the body is ensured again until the next respiratory failure occurs.

This process is repeated several times to hundreds of times during the night for people with sleep apnea. Patients usually cannot remember it the next day, but sleep apnea ensures that their sleep is not very restful. As a result, those affected usually suffer from severe tiredness during the day.

Obstructive sleep apnea mainly affects older men: Between the ages of 40 and 60, about 20 percent of them suffer from sleep apnea syndrome, between 65 and 70 it is already 60 percent. Women are often spared from sleep apnoea until the menopause. But why is this so? “It is still not clear whether it is due to different hormones or anatomy, or whether it is simply inherited differently,” said Prof. Fietze.

2. Central sleep apnea

Only about one in ten cases of sleep apnea is referred to as central sleep apnea, the cause of which is located in the brain and can be caused by a cardiovascular disease such as heart failure or a stroke. In this case, the respiratory control centre in the brain no longer sends an impulse to breathe. Only when the carbon dioxide that has not been exhaled rises above a critical level in the blood does the brain send a new impulse to breathe. In some patients, breathing is very shallow before the breathing stops – this is known as Cheyne-Stokes breathing.

The probability of developing central sleep apnea increases with age. It is estimated that one in four people over 60 is affected.

If I suspect sleep apnea, do I have to go to a sleep lab?

If sleep apnea is suspected, it can usually be checked from home first. For this purpose, the patient is loaned certain measuring devices by the doctor, which record all information on breathing or breathing pauses, pulse, oxygen content in the blood and body position. This measurement is called polygraphy and is often sufficient to make an initial diagnosis.

For a more thorough examination or to confirm the suspicion of a sleep apnea syndrome, the doctor may also refer the patient to a sleep laboratory, where the so-called polysomnography is performed. The examinations there are more extensive than the measurement at home, but they are absolutely painless and most patents do not disturb sleep.

Therapy: How can sleep apnea be treated?

Sleep apnea is usually treated individually, depending on the form, different types of therapy can be used. The following treatment methods can be used:

• Breathing mask: The special breathing mask is worn at night. Via a device connected by a breathing tube, room air is blown into the nose (or nose and mouth) and thus into the throat and lungs with the aid of slight positive pressure, thus preventing the closure of the upper airways and thus breathing disorders. Usually the patient learns how to use the mask correctly in the sleep laboratory.
• Losing excess weight: In obstructive sleep apnea, it often helps to lose excess weight in order to at least relieve sleep apnea, and rarely to get rid of it.
• Devices that prevent the supine position: Only when sleep apnea occurs almost exclusively in the supine position, devices that trigger an alarm when the sleeper wants to turn on his back are helpful. It may be enough to sew a tennis ball into the back part of the pyjamas. Recommended only for otherwise good sleepers.
• Sleeping high up: If the upper body is slightly elevated, it is easier to prevent the tongue from slipping down the throat or liquid from accumulating in the neck area. This can also be a remedy for mild sleep apnea.
• Bite splints: In mild and moderate cases, specially made bite splints can prevent sleep apnea.
• Avoidance of stimulants: typical stimulants such as alcohol and cigarettes should be avoided.
• Change of medication: If medication triggers sleep apnoea, you should talk to your doctor about whether there are any alternative preparations.

Operation for sleep apnea: How useful is this therapy?

If the sleep apnoea has anatomical reasons, surgery can be considered depending on the case, says Prof. Fietze: “If the tongue is low and the soft palate including the uvula constricts the airway relevantly, minimally invasive surgery is sometimes useful. It is indicated if the tonsils are also significantly enlarged. In some patients, a so-called tongue pacemaker can also be used to stimulate the nerve that controls the tongue muscles. This keeps the airways open at night.

The patient should clarify individually with his or her doctor which therapy should be considered.