(Reuters Health) - Many people who suffer from sleep apnea continue to suffer excessive daytime sleepiness despite standard treatment with continuous positive airway pressure, or CPAP.
Sleep apnea occurs when the soft tissues at the back of the throat temporarily collapse during sleep, causing repeated breathing interruptions. Major symptoms include loud snoring and daytime sleepiness -- the latter of which, studies show, may cause irritability, cloud thinking and concentration, or increase the risk of traffic accidents.
CPAP treatment involves wearing a special face mask that delivers pressurized air to keep the airways open overnight.
In a study of 502 patients from 37 sleep centers who were using CPAP, researchers found that 6 percent continued to experience excessive daytime sleepiness.
"In France alone," study leader Dr. J-L. Pepin, from CHU de Grenoble, France, said in a statement, "we have 230,000 patients using CPAP. We calculate that at least 13,800 of those have residual daytime sleepiness."
Pepin and colleagues report their findings in the European Respiratory Journal for May.
On initial analysis, 12 percent of patients had residual excessive sleepiness at 1 year, but after adjusting for possible confounding factors, including restless leg syndrome, depression, and narcolepsy, the prevalence of residual excessive sleepiness fell to 6 percent.
Daytime sleepiness was associated with reduced quality of life. According to the investigators, subjects with this problem showed poorer emotional health and less energy than did their peers who responded completely to CPAP therapy and did not report being sleepy during the daytime.
SOURCE: European Respiratory Journal, May 2009.