Sleep Apnea

Clinical trials and Sleep Apnea

What is sleep apnea? What is “apnea”? If you listen to someone close to you while they’re sleeping and notice that their regular snoring is interrupted at times, during which they appear to stop breathing, their chest and abdomen expand in an attempt to take in air, and this lasts for more than 10 seconds, sometimes even a minute, and ultimately ends with a loud snort and the resumption of breathing, then that person likely suffers from sleep apnea.

Sleep apnea is a disease of our modern times. According to studies in recent years, almost every fifth man suffers from some form of sleep apnea. Women are less affected than men, with only about one in ten women being affected by the disease.

However, after menopause, the risk becomes equal for both sexes. The more weight a person gains and the older they become, the more predisposed they are to developing sleep apnea. Structural changes in the nose and throat, such as enlarged tonsils, an enlarged uvula, etc., frequent alcohol consumption, smoking, the presence of gastroesophageal reflux, and first-degree relatives with sleep apnea are also factors that increase the risk.

Sleep apnea involves repeated pauses in breathing during sleep. The consequences are low oxygen levels in the blood and disrupted sleep quality. Long-term illness of this kind increases the risk of cardiovascular events (heart attack and stroke), metabolic disorders (diabetes, high cholesterol, high uric acid, obesity), and central nervous system disorders (excessive daytime sleepiness, memory and concentration problems, irritability, depression).

Sleep apnea is a chronic disease. Like arterial hypertension and diabetes, it is a condition that develops over the years, often with symptoms that the patient does not feel, is unaware of, or does not know about. Similar to hypertension and diabetes, it is primarily dangerous for the complications it leads to.

Types of Sleep Apnea. There are generally two types of sleep apnea: obstructive and central. The difference between them lies in the mechanism by which the characteristic breathing pauses, known as “apneas” (translated from Latin as “absence of breath”), occur during sleep.

In obstructive sleep apnea, the individual stops breathing while sleeping because the muscles in the throat relax and collapse, causing the upper airways to become blocked and preventing the airflow from the mouth and nose to the lungs. The mechanism of apnea in these cases is similar to someone choking another person by grabbing their throat.

The decrease in oxygen in the blood due to this choking stimulates the brain, triggering a brief arousal (microarousal) that the sleeper does not remember or even consciously perceive. The microarousal signals the body to send impulses to the collapsed muscles, increasing their tone and opening up the upper airways.

Breathing is then restored, and the individual resumes breathing. In addition, loud snoring may be observed, which momentarily ceases and stops for a certain period (seconds to minutes), followed by a loud snort and resumption of breathing for a certain period before another breathing pause occurs.

Central sleep apnea is less common than obstructive sleep apnea. In this type, the mechanism of apneas is different. The individual stops breathing because the respiratory center in their brain temporarily fails to send signals for breathing, leading to the inhibition of respiratory muscles (chest and diaphragm muscles).

When the respiratory muscles do not move, the lungs are not ventilated, and the airflow in the airways ceases. This type of apnea is less prevalent and is most often associated with concurrent heart conditions (such as atrial fibrillation, heart failure, etc.), neurological disorders, and kidney diseases.

Apnea-Hypopnea Index (AHI) Even healthy individuals experience breathing pauses during sleep. When these pauses are within certain normal limits, they are not considered a medical condition. The indicator of “how many times a person stops breathing per hour of sleep” is called the Apnea-Hypopnea Index (AHI).

The number of pauses per hour determines whether the patient has apnea, what type it is (obstructive or central), how severe it is (mild, moderate, or severe), and consequently, what treatment should be applied. AHI is calculated through sleep breathing studies. The standard method to do this is through polysomnography conducted in a laboratory setting.

During this study, the patient spends a night in a sleep clinic where various parameters of their sleep (brain activity, heart activity, breathing, etc.) are recorded using special equipment under the supervision of a physician or nurse.

For individuals at high risk of sleep apnea and based on the physician’s assessment, a simpler breathing study, known as respiratory polygraphy, can be conducted in an outpatient setting, i.e., at the patient’s home.

The treatment of sleep apnea is determined by its severity and whether it is obstructive or central. As a chronic condition, it requires chronic treatment. Similar to the treatment of arterial hypertension and diabetes, the treatment of sleep apnea does not lead to complete cure but aims to maintain the disease within normal limits.

The main method is the so-called PAP therapy (Positive Airway Pressure). With this therapy, the patient breathes with a mask while sleeping. The mask is placed on the face and connected to a device that delivers room air under pressure, i.e., at a higher volume.

As the air enters the upper airways in the throat area, it separates the relaxed and collapsed muscles, creating a sort of air splint that prevents snoring and allows normal breathing during sleep.

Like any chronic disease, the treatment of sleep apnea requires lifestyle changes for the patient. Adhering to good sleep hygiene, avoiding risk factors that increase the frequency of apneas, weight reduction, and treating accompanying diseases are essential elements in the therapy.

Treatment for moderate and severe forms of sleep apnea is always performed with a PAP device because it is believed that, despite general treatment approaches for sleep apnea, complete cure cannot be achieved. All newer PAP devices have a memory card that records the patient’s breathing and calculates the AHI in conjunction with device usage.

This way, the sleep medicine specialist can monitor the treatment, and periodic data checks are important for evaluating the therapy’s effectiveness.

The prognosis for individuals with sleep apnea is good. Sleepiness disappears completely within the first few days of using the device. Regular PAP therapy reduces the risk of complications associated with the disease. Long-term improvements in snoring and breathing during sleep are expected with significant weight reduction in overweight individuals and regular use of the device. In these cases, the AHI decreases but rarely reaches normal limits, so therapy should not be discontinued for extended periods of time.

A clinical research center is dedicated to sleep apnea clinical trials. We are specialized facility that focuses on conducting research studies related to sleep apnea. Convex clinical research unit plays a crucial role in advancing medical knowledge, improving diagnostic techniques, and developing new treatments for sleep apnea.

By conducting clinical trials in Convex dedicated research center, our scientists and healthcare professionals can gather valuable evidence to improve the diagnosis, management, and treatment of sleep apnea.