Untreated Sleep Apnea Can Double the Risk of Sudden Death From Stroke or Cardiac Arrest, New Study Finds

Untreated Sleep Apnea Can Double the Risk of Sudden Death, Study Finds

By Admin

While health risks associated with sleep apnea are well documented in research literature, a new study affirms that the condition dramatically increases the risk of early mortality due to stroke, cardiovascular disease, and other comorbid conditions. Published in the journal BMJ Open Respiratory Research, the study focuses primarily on what is known as sudden death, which is a death that is unexpected and occurs within minutes of any cause or symptoms. For sleep apnea, this often occurs during sleep or shortly after waking, giving the patient very little time to react or call for help. According to the study, people with sleep apnea have a nearly twofold higher risk of cardiovascular mortality and all-cause sudden death than those without the disorder, and the risk increases with both disease severity and age.

"Our research shows this condition can be life-threatening," principal investigator Anna Ssentongo, Ph.D., said in a press release about the study. As an assistant professor of epidemiology at Penn State, Dr. Ssentongo led the study’s primary focus on quantifying and assessing the link between sleep apnea and sudden death events, concluding that the research “adds to the growing body of evidence that highlights the importance of screening, diagnosis, and treatment of sleep apnea,” which can save lives and improve quality of life for patients all over the world.

The Study

Published in June of this year, the study on sleep apnea and sudden death includes a systematic review and meta-analysis of previous studies on sleep apnea and early mortality. Focusing specifically on obstructive sleep apnea (OSA), the study team reviewed 22 previous studies that included over 42,000 patients worldwide. By synthesizing the data from previous studies, the team was able to quantify the risk of sudden death as a twofold increase in the likelihood of an event, as compared to those without a sleep apnea condition. In addition, the team found that the risk increased with age and disease severity (known as a dose-response relationship). But while the authors noted that risk was higher among those with severe sleep apnea, the risk level for mild cases was still considerably higher than those of the general population.

Among the study’s key points was the risk of sudden death for sleep apnea patients, the significance of age and disease severity as additional risk factors, and the importance of further study to better understand the relationship between sleep apnea, early mortality, and other related health conditions.

What is Sudden Death?

Sudden death is any death that is unexpected due to lack of prior symptoms or sufficient response time following any warning signs. More specifically, sudden cardiac death (SCD) is a death due to sudden cardiac arrest, when the heart stops beating due to a disruption of the pumping system that pushes blood to the rest of the body. According to the CDC, sudden cardiac death is the largest cause of natural death in the U.S., responsible for over 325,000 deaths each year (roughly half of all heart disease deaths in the country).

Unlike a heart attack, which is caused by blockage of the arteries, cardiac arrest is when the heart’s electrical system malfunctions due to irregularities (arrhythmias). But heart attacks and cardiac arrests can happen together, either at the same time or in close succession, and both can occur as sudden death events.

Following sudden cardiac arrest, cancer, and respiratory illnesses, stroke is also a leading cause of death in the west. In 2018, one in every six deaths from cardiovascular disease was due to stroke, and a high percentage of those deaths occured at night or during sleep. While sudden deaths do not have to occur at night or during sleep, those instances are very common among the elderly, and particularly for those with sleep apnea.

Sleep Apnea and Mortality: An Overview

Sleep apnea is a condition with a high rate of comorbidity and related health problems, which are greatly exacerbated by lack of treatment or lack of consistent adherence to prescribed therapies. Along with heart conditions, diabetes or other metabolic problems, and blood pressure or circulatory concerns, the cessation of breathing and fragmented sleep patterns associated with apnea events often lead to extended periods of high blood pressure known as hypoxemia, an off-and-on deficiency in the supply of oxygen to the tissues of the body. In response to this, the body often increases its inflammatory response and escalates the nervous system to fight the perceived threat.

All of this can happen during sleep, but more often, an individual will wake periodically throughout the night in order to catch a breath and attempt to return to sleep. This, in turn, makes it extremely difficult to achieve the deepest levels of sleep needed for physical renewal, contributing to further problems that last through the day hours and disrupt the sleep-wake cycle. As a result, people with sleep apnea often have other debilitating health conditions.

According to the one report, roughly 70 percent of stroke victims have some form of sleep apnea, and nearly every type of cardiovascular disease is associated with sleep disordered breathing, In order to better understand these comorbid relationships, study authors suggest that a higher priority should be placed on sleep research in general, and on sleep apnea in particular. With risks as severe as sudden death, and sleep disorders such as sleep apnea affecting nearly a billion people worldwide, it should be clear how important this area of study is for the future of healthcare.