TUESDAY, June 11, 2013 —Obstructive sleep apnea (OSA) takes a person’s breath away throughout the night, but the corresponding increased risk of sudden cardiac death shows that it might also take someone’s breath away forever, according to a study from the Journal of the American College of Cardiology.

The largest study of its kind looked at 10,701 patients from 1987 to 2003 suspected to have difficulty breathing during sleep. Subjects were 18 years or older, and had not been previously diagnosed with OSA.

During the 15 year sample, 142 patients had fatal or resuscitated sudden cardiac death. These patients were more likely to be over the age of 60 and had poor results on daytime and nighttime oxygen saturation tests — problems commonly associated with sleep apnea.

"Sleep apnea is characterized by a drop in blood oxygen levels, which creates strain on the heart," said Mary Ann McLaughlin, MD, associate professor of Cardiology and Medical Director of the Cardiac Health Program at The Mount Sinai Medical Center in New York City, who was not affiliated with the study. "To compensate for the low oxygen, the body may increase blood pressure, which we know can lead to a heart attack or stroke."

Researchers found that the risk of sudden cardiac death increased significantly in patients with an average of five years of obstructive sleep apnea. Even people with moderate cases of sleep apnea were at a significantly increased risk of cardiac death.

The study authors hope future research will continue to look at the link between cardiac death and sleep apnea. Future clinical trials should look to develop sleep apnea therapy targeted at people with a higher risk for cardiac death.

Sudden cardiac death kills approximately 450,000 people per year in the U.S. The condition is often fatal because it causes the heart to stop beating and requires immediate resuscitation through CPR or a defibrillator.

Approximately 18 million Americans are currently living with sleep apnea. The debilitating disorder causes 5 to 30 pauses in breathing per hour of sleep.

"Obstructive sleep apnea occurs when the upper airway is narrowed during sleep and causes a lack of oxygen," said Michael Coppola, MD, past president and chief medical officer of the American Sleep Apnea Association, and NovaSom chief medical officer. "The most common symptom associated with it is nightly snoring."

Sleep apnea has been linked to other cardiovascular diseases, such as: atrial fibrillation, hypertension, and heart failure.

"Being overweight, male, older age, and a smoker are common risk factors in both sleep apnea and cardiac death," explained Dr. McLaughlin.

Sleep Apnea and Cardiovascular Disease

In general, poor sleep has been linked to an increased risk of heart disease. But obstructive sleep apnea has specifically been linked to cardiovascular conditions in studies before the latest American College of Cardiology study.

Previous research has discovered that sleep apnea can be associated with an increased risk of heart failure. This finding caused researchers to test the benefits of sleep apnea treatment not only for patients dealing with that condition, but for patients who might also be at a higher risk for heart failure.

In 2012, researchers from the University of Birmingham Center for Cardiovascular Sciences found that six months of sleep apnea treatment can negate some of the disorder’s effects on the heart, and decrease the risk of heart failure.

Sleep apnea has also been linked to artery damage — which can lead heart attack and stroke. 

Recently, a link was found between obstructive sleep apnea and hypertension. High blood pressure was discovered in nearly 60 percent of patients with severe sleep apnea, according to research from the American Academy of Sleep Medicine.

"Anyone with sleep issues should practice good sleep hygiene," concluded Dr. McLaughlin. "This includes maintaining a normal sleep schedule, avoiding alcohol, nicotine, caffeine and heavy meals before bedtime, and not using the TV or computer in bed."

"All people should plan for enough time and the proper circumstances for restful sleep. With diet and regular exercise, sleep is part of the healthy triangle we all must manage to stay healthy," added Dr. Coppola. "If someone has symptoms of sleep apnea: snoring, witnessed choking or apnea at night, and excessive daytime sleepiness, they should seek medical attention as soon as possible."