Sleep apnea is a condition in which a person has frequent interruptions of breathing when sleeping. Sometimes it happens because of an abnormal relaxation of the throat and tongue muscles. It's also common in obese people.
Kevin K. Brown, MD, and colleagues at Denver's National Jewish Medical and Research Center, noticed that many adults with asthma also have sleep apnea. They looked at 80 consecutive patients who came to their facility with hard-to-control asthma. The 31 patients suspected of sleep apnea were given additional tests.
Sure enough, 20 of these patients turned out to have obstructive sleep apnea. This meant that, overall, one in four hard-to-treat adult asthma patients had the condition. Men and obese patients were much more likely to have both asthma and sleep apnea.
Brown reported the findings at this week's annual meeting of the American Thoracic Society.
"Obstructive sleep apnea is common in difficult-to-control asthmatics, particularly males and those with [obesity]," Brown and colleagues write in their presentation abstract. "[Sleep apnea] should be considered as a potential reversible cause of [hard-to-treat asthma] symptoms."
As only selected patients underwent testing, the researchers suggest that the actual rate of sleep apnea and asthma may be higher than 25%.