Studies Show Risks Of OSA, Obesity And Need for Treatment

At the American Thoracic Society 2007 International Conference, held in San Francisco May 18-23, numerous studies on respiratory and sleep medicine were presented. Highlights from three documenting the risks associated with obstructive sleep apnea and obesity follow.

Long-Term Study Shows OSA Heightens Risk of Heart Attack, Death

Obstructive sleep apnea increases a person's risk of having a heart attack or dying by 30 percent over a period of four to five years, according to a new study.

The more severe the sleep apnea at the beginning of the study, the greater the risk of developing heart disease or dying, the results revealed.

The study, called “Obstructive Sleep Apnea Is Associated with an Increased Risk of Coronary Artery Disease and Death,” included 1,123 patients referred for sleep apnea evaluation. They underwent an overnight sleep study to determine if they had sleep apnea. Over the next four to five years, they were followed to see how many had any heart disease events (heart attack, coronary angiography or bypass surgery) or died.

“While previous studies have shown an association between sleep apnea and heart disease, ours is a large study that allowed us to not only follow patients for five years and look at the association between sleep apnea and the combined outcome of heart attack and death but also adjust for other traditional risk factors for heart disease,” said researcher Neomi Shah, M.D., of Yale University.

“We recommend that patients who experience symptoms of obstructive sleep apnea — excessive daytime sleepiness, or snoring along with breathing pauses — consult their physician,” said Shah. “There is some evidence to make us believe that when sleep apnea is appropriately treated, the risk of heart disease can be lowered.”

In OSA, the upper airway narrows, or collapses, during sleep. Periods of apnea end with a brief partial arousal that may disrupt sleep hundreds of times a night.

Sleep apnea triggers the body's “fight or flight” mechanism, which decreases the amount of blood pumped to the heart. Repeated episodes every night for a few years can starve the heart of enough oxygen when it is combined with the body's decreased oxygen intake due to the frequent breathing stoppages during the night, Shah said.

According to the researchers, CPAP is the most effective treatment for sleep apnea and has proved successful in many cases in providing a good night's sleep, preventing daytime accidents due to sleepiness and improving quality of life.