People suffering from obstructive sleep apnea are more likely to experience higher psychological stress and therefore heart problems during air travel, new research shows.

Obstructive sleep apnea (OSA) is caused by a blockage of the airway, usually when the soft tissue in the rear of the throat collapses and closes during sleep. Actually, the Greek world “apnea” literally means “without.”

According to the National Institutes of Health, sleep apnea is very common, affecting more than twelve million Americans. Risk factors include being male, overweight and over the age of forty, but sleep apnea can strike anyone at any age, even children. Worrisome is the fact that around 80 percent of men and 93 percent of women with sleep apnea are unaware they have this disorder, despite the fact that it can have significant consequences.

Untreated, sleep apnea can cause high blood pressure and other cardiovascular disease, memory problems, weight gain, impotency, and headaches.

Now a new study by Australian researchers, called “Effects of Commercial Flight Simulation in Patients with Obstructive Sleep Apnea” showed that sleep apnea endangers peoples’ lives during air travel.

Lead author Leigh Seccombe, MSc, of Concord Repatriation General Hospital in Sydney and colleagues investigated the physiological response of 22 patients with severe OSA and without lung disease, to a simulation of an aircraft cabin and compared the results to that of 10 healthy subjects.

More exactly, the researchers looked at the participants’ ventilatory response and at the amount of oxygen circulating in their bloodstream during the simulation.

The study found that people with OSA had lower levels of oxygen in their blood before and during the simulated flight. Also, these people experienced higher heart rates, physiological stress and demand for oxygen than healthy people.

"Patients with OSA, without lung disease, are more likely to develop significant hypoxemia [low blood oxygen] and have increased oxygen demands during flight,” the study concluded.

Seccombe noted that if the results of this study are typical “half of the patients with obstructive sleep apnea would require supplemental oxygen in-flight [for those with lung disease] are strictly followed.”

She also said that she and her colleagues decided to look at this issue, as obesity is in a continuous raise among Americans, thus boosting the number of people with OSA.

“We addressed obstructive sleep apnea because it is becoming so much more common as obesity increases and there are greater numbers of obese passengers on commercial flights,” Seccombe said, as quoted by the New York Times.

The findings of the study were presented on Sunday, May 18th, at the American Thoracic Society’s 2008 International Conference in Toronto.