From snoring to apnoea

Plenty of people snore and yet do nothing about it. At what point does snoring become a health issue?

Snoring in adults is seen primarily as a social issue. The person who snores is not the one in trouble, and the problem affects the person they sleep with, as they are the ones who wake up multiple times each night and experience affected sleep. On the other hand, there is no data that would indicate that snoring itself would prove dangerous. The situation changes dramatically in the case of dealing with sleep apnoea, a severe disease which can be described as a continuation and aggravation of snoring.

How does it occur?

As I said before, it all starts with snoring This phenomenon is caused by the air that passes through the airways, encountering an obstruction in the throat or nose. It is mainly heard at the inhalation stage. This is when snoring becomes more frequent and tends to get louder. Over time, snoring starts to be accompanied by what is commonly referred to as shallow breathing. It basically means that lower volume of air is drawn into the lungs with each breath. The next stage is apnoea, meaning that that the airflow stops. A typical apnoea even goes like this: the person’s snoring is abruptly stopped by a moment of silence – a breath held for at least 10 seconds or more. Afterwards, the person typically gasps for air and wakes up. This is the human body’s way of defending against breathlessness. The respiratory drive increases and the breathing muscles tighten. The person breathes faster, which in some cases involves even louder snoring. Then apnoea occurs again and the entire cycle is repeated. This specific type of snoring with apnoeic events requires treatment, as it may affect the development or aggravation of a number of diseases – primarily cardiovascular diseases.

What percentage of snorers may potentially suffer from apnoea?

The latest data shows that up to 20 per cent of adults in the general population in Western European countries and the United States suffer from apnoeic events. If we superimpose the data that 40 per cent of adults who snore, we find that nearly one in two snorers also experience apnoea. This is a significant portion of patients. This group includes both men (slightly more often) and women, the elderly and the young. For this reason, if someone snores every night for months or years, they should undergo a simple screening to rule out potential sleep apnoea. Such examination is required also in cases where nobody has ever noticed uneven breathing during sleep.

So far, we have discussed adults, but what about children who snore?

Things are significantly worse in this case. Habitual regular snoring in a several-year-old, even without apnoea or hypoxia, must be treated as a disease and should not be taken lightly. However, a snoring child is often perceived as experiencing a strong, healthy sleep. This is a myth. In the case of children who ‘only’ snore, complications develop just as often as in toddlers who suffer from apnoea. Snoring children tend to be irritable during the day, their attention focus abilities tend to be impaired, just as their learning skills and social interactions. Molecular studies also show that their cardiovascular system is strained. In light of all the facts, a child who regularly snores for months should be treated. 

Why do some people snore while others do not?

The most obvious and visible risk factor for snoring and apnoea is obesity. Fatty tissue is not only deposited on the abdomen and hips. It is also found in the tongue, throat and palate. This means that our airways narrow when we gain weight. The second risk factor, which is quite easy to observe, is malocclusion. Primarily involving narrowing of the jaw or mandible or retraction of the mandible. These defects cause the soft tissues, i.e., the tongue and palate, not fit properly into the upper airways, obstructing the flow of air. In addition, there are plenty of ENT factors which interfere with the permeability of the upper airways, the nose and the throat and thus cause snoring. As far as the nose is concerned, these factors may include a deviated septum, hypertrophy of nasal concha and chronic sinusitis with polyps. All of these changes result in a chronic runny nose and the sensation of a blocked nose.  This causes us to breathe through the mouth when sleeping, which causes us to start snoring. Blockages can also occur at the level of the throat. In children, this is most often the so-called third tonsil. In adults: the palatine tonsils, the uvula, the base of the tongue.

How does sleep apnoea affect our daily lives?

Persons who suffer from sleep apnoea may sleep for seven, eight or even ten hours, but in the morning, they are going to feel as tired as they did in the evening, or in some cases even more so. Their sleep pattern is disrupted at night. They alternate between shallow and deep sleep and their sleep is very fragmented. Apnoea itself can be compared to suffocation. A person who experiences 30 apnoeic episodes per hour may wake up in the morning feeling as if somebody was trying to suffocate them the entire night. The body feels like it is fighting for its life and it is very draining. Not surprisingly, fatigue, impaired concentration and sleepiness quickly set in during the day. In addition, it is also widely known that persons who suffer from sleep apnoea are more likely to make mistakes and have accidents both at work and on the road.

You previously mentioned health consequences. What conditions tend to develop in consequence of sleep apnoea?

Sleep apnoea results in hypoxia. This in turn affects in particular the vessels, the heart and the brain, as they are very sensitive to even brief periods of hypoxia. Each apnoea and the subsequent so-called apnoeic phase involve fluctuations in heart rate, blood pressure and respiratory rhythm. During an apnoeic event, the heart rate slows down, while the blood pressure drops. At the stage after the apnoeic event, these parameters tend to increase, as the heart rate and blood pressure rise back again. Again, instead of rest and recovery, the body swings between states.  Consequentially, persons who experience apnoea are much more likely to develop cardiac arrhythmias. Episodes of hypoxia also promote chronic inflammation, which accelerates the development of the atherosclerotic process. This causes damage to arterial walls, the heart muscle or the central nervous system. What are the consequences? Well, primarily hypertension, cardiac arrhythmias, ischaemic heart disease, heart attacks and strokes, as well as metabolic disorders, i.e., glucose intolerance, diabetes, hypercholesterolaemia, unbalanced lipid profile. For these reasons, persons who have been snoring for a long time may need to undergo medical examinations.

How to recognise apnoea?

There is a variety of examinations available, ranging from very simple to very complex. There examinations are performed at night, when the patient is asleep. We monitor the sleep and record numerous parameters. Pulse oximetry is the simplest technique. Most of us are familiar with that examination due to the COVID-19 era. In the case of sleep testing, we use pulse oximeters that record and store data. In the morning, we get the results from the entire night. They allow us to analyse the saturation curve and check for hypoxia. In the case of persons with suspected apnoea, we can also perform polysomnography. This complex test is done in a hospital setting. Our facility is equipped with three polysomnography stations. They are occupied almost every day, including weekends. This results in 60-80 polysomnographies performed every single month. A patient is admitted to a hospital in the evening, we put multiple electrodes on him or her and connect them to the equipment. The machine measures plenty of varied parameters and provides the most accurate assessment of sleep quality. However, even this method is not ideal, as sleep in a hospital bed is not fully reliable.

And what treatment methods are available?

Most often, we use CPAP machines. These devices include a machine which generates positive airway pressure, a connecting tube and a mask to be positioned over the nose or over the mouth and the nose. The patient sleep in this mask. The air provided through this mask has a slightly higher pressure. This allows CPAP to widen the airway tract and the patient is able to breathe in and out more comfortably. These masks are not very comfortable to use, however they are and effective, non-invasive and safe method. There are no risks involved, however many patients stop using them after a month or two. Treatment with a CPAP machine brings benefits if the mask is used every night. Some patients can be easily persuaded into using the device, but others may not be talked into it. There are other options available. There are surgical methods available for some patients, such as straightening a deviated septum or removing polyps... Intraoral devices are also being introduced, the most modern methods such as the sublingual nerve stimulator. It works similarly to a pacemaker – it stimulates the nerve responsible for tightening the muscles of the tongue. Three companies exist which registered this product. It is however very expensive and it is not refunded by the National Health Fund.

What can we do to stop snoring?

Persons who only snore or experience singular apnoeic events can try to follow some simple methods to help themselves. It is worthwhile to use applications which measure the intensity of snoring, suggest possible causes of the problem and methods of improving the situation. You can also put your pillow a little higher, use medications which improve the permeability of the nose or other remedies for snorers. Lifestyle changes, such as increased physical activity, quitting smoking and avoiding alcohol consumption, in particular before going to bed, are also going to help. In the case of obese snorers, the best method is to lose weight.

Interviewed by Iwona Kołakowska
Photo by Michał Teperek
University Communication and Promotion Office