Symptoms include excessive daytime sleepiness, loud snoring, awakening with a dry mouth or sore throat, observed episodes of breathing cessation and morning headaches, according to the Mayo Clinic
"Obstructive sleep apnea is a disorder of symptomatic, repetitive pauses in your breathing during sleep," said Dr. Sebastian Jara
, a resident physician in otolaryngology/head and neck surgery at University of Washington Medicine in Seattle and a leading author of the new study.
"It's a very common chronic disease that's often underdiagnosed in patients, and there's a lot of treatments you can do to prevent different downstream health effects from sleep apnea."
CPAP machines are among the most common treatments for obstructive sleep apnea. They rely on a hose and mask to deliver constant and steady air pressure while a person sleeps and are thought to improve a number of complications associated with sleep apnea, including daytime fatigue, high blood pressure and sexual dysfunction, according to the Mayo Clinic
The new study, published Thursday in JAMA Otolaryngology-Head and Neck Surgery
, looked at the effectiveness of CPAP machines in improving the sexual quality of life of 182 men and women recently diagnosed with obstructive sleep apnea. The researchers compared perceived changes in sex life between 72 people who used the machines regularly and 110 who did not over the course of a year.
The researchers found that, overall, use of the airway pressure machines for at least four hours every night significantly improved perceived sexual quality of life in men and women, based on a self-reported questionnaire. Specifically, they found that regular use of the machines improved sex life by an average of 0.7 points on a scale of 0 to 5.
"This is good news, because it says you're not only going to be more awake and have less snoring -- you're also going to be sexier," said Dr. Rafael Pelayo
, clinical professor at the Stanford Center for Sleep Sciences and Medicine, who was not involved in the new study.
A 1-point improvement on the scale corresponds to a change in 1 category level of severity of sexual dysfunction. For example, it would correspond to a person changing his or her perceived sexual dysfunction from moderate (a score of 3) to mild (a score of 2) or from mild (a score of 2) to very mild (a score of 1), according to the study.
"It's not surprising that patients that have improved oxygen levels during sleep may have improved sexual performance," said Dr. Robson Capasso
, chief of sleep surgery at the Stanford School of Medicine, who was not involved in the study.
Sleep apnea affects approximately 25% of men and 9% of women, according to Capasso. But rates are much higher among postmenopausal women than premenopausal women, he said.
"The women are usually postmenopausal women, and the sexual dysfunction may be implicated by the menopause. But this suggests that if you treat the sleep apnea, you may get better," Capasso added.
When the researchers separated the participants based on gender, they found that most of the improvement in sexual quality of life was among women. Specifically, perceived improvements in sex life were nearly nine times greater in women than men.
"We were surprised to see that we had a strong effect in the women in our study but minimal to no effect in the men in our study," Jara said. "We don't have a great answer for it at this point."
This is in contrast to studies suggesting that use of positive airway pressure machines improves sexual functioning in men more than women, according to Pelayo.
A 2010 study
, for example, showed that use of the machines for a period of a year improved sexual satisfaction and reduced erectile dysfunction among 123 men with obstructive sleep apnea.
"We've had male patients tell us that their wives want to unplug their machines because they get too frisky when they're on CPAP because they feel better," Pelayo said.
study also suggested that CPAP treatment mildly improved sexual dysfunction in female patients with sleep apnea, but had no effect on sexual distress or overall satisfaction after one year.
"What's fascinating to me about this is that even though, for years, I've been talking about sexual dysfunction with my patients, I'm embarrassed to say I've always focused on my male patients because we think of erectile dysfunction as the issue," Pelayo said. "But in this study, they found that women were actually the ones who were driving the positive effects of CPAP."
The new findings also suggest that wearing a CPAP machine may not be detrimental to one's sex life, as some people believe, according to Pelayo.
"A lot of our single patients are worried that they're not going to be attractive to their bed partner if they wear the CPAP -- that they're going to be unattractive," Pelayo said.
"And I tell them quite the opposite -- that once you use the CPAP, actually you're going to be feeling better and you're not going to be snoring. There's nothing sexy about snoring," he added.
It is unclear why the sexual benefits of airway pressure machines were more pronounced in women than men in the new study, according to Jara.
"One of the reasons why our findings may have been different from past studies, at least in men, is that a lot of past studies looked at men with sleep apnea who also had a form of sexual dysfunction at baseline. So improvements were noted, but they were noted in a patient population that already had more sexual dysfunction," he said.
The precise mechanisms linking improved sleep with improved sexual functioning are also not fully known, Pelayo added.
"It doesn't tell us what the mechanism is. Was there a secondary issue to mood? Was it a vascular effect? Or did people maybe lose a little bit of weight afterwards?" he said.
The researchers found that the association remained even after controlling for factors such as age, race and ethnicity, marital status, income level and body mass index, according to Capasso.
The study only relied on two questions to evaluate sexual quality of life, one of the main limitations of the research, Capasso said.
But the results still suggest that regular use of CPAP machines could have benefits beyond decreased drowsiness for those with obstructive sleep apnea.
"There's a lot of evidence that CPAP improves overall health and quality of life in both sexes with sleep apnea," Jara said.
"Also, because sleep apnea is less recognized in women, our hope is that this will provide further evidence that patients should be evaluated and treated for sleep apnea."