A continuous positive airway pressure (CPAP) machine can relieve not only sleep apnea but the heartburn and chronic cough that often accompanies it, a new study finds.
People who suffer from sleep apnea are three times more likely to develop acid reflux than those who don't have the condition, noted senior researcher Dr. Thorarinn Gislason, from the Department of Sleep of Landspitali--National University Hospital of Iceland.
Still, Gislason doesn't think that people with acid reflux should be tested for sleep apnea unless they have other symptoms.
"We have a long list of symptoms and complications from sleep apnea, including daytime sleepiness, respiratory symptoms like coughing or wheezing," he said. "If you have these symptoms, you might consider being evaluated for sleep apnea."
Sleep apnea occurs when the muscles in the back of the throat relax too much, causing the airway to narrow or close. If you don't get enough air, you wake up to open your airways. This awakening is usually so brief that you don't remember it. You might snort, choke or gasp. This pattern can repeat itself five to 30 times or more each hour, all night.
This constant interrupted sleep has serious health consequences. Sleep apnea can raise the risk for daytime sleepiness, cardiovascular problems, type 2 diabetes and liver issues.
The most effective treatment for sleep apnea is CPAP, Gislason said.
"It's the most effective treatment as it puts you in the same situation as those who do not have obstructive sleep apnea," he explained. "If you use the device all night, every night, then you're in the same situation as those who do not have obstructive sleep apnea at all."
Dr. David Hill, an assistant clinical professor of medicine at Yale University School of Medicine and a volunteer medical spokesperson for the American Lung Association, explained why acid reflux is linked to sleep apnea.
"When patients are having airflow obstruction that occurs in sleep apnea, they breathe harder to try to overcome it," Hill said. "That can cause the reflux to worsen because they are causing acid to rise in to the esophagus and potentially into the lungs. Relieving sleep apnea ends up making the breathing easier and helps relieve the reflux."
For the study, published online Aug. 31 in the journal ERJ Open Research, Gislason and his colleagues studied 822 patients in Iceland diagnosed with moderate to severe sleep apnea.
Before CPAP treatment started, the patients took part in an overnight sleep study and completed sleep questionnaires, including if they had heartburn or belching at night.
After two years, the patients had a follow-up evaluation where researchers measured data stored by their CPAP machines.
The researchers found that those who used CPAP regularly were about 42% less likely to suffer nighttime heartburn, compared with those who used CPAP a little or not at all.
The decrease in acid reflux resulted in a more than fourfold reduction in morning cough with mucus and an almost fourfold decrease in the risk for chronic bronchitis. Regular CPAP users were also less likely to suffer from wheezing, the researchers noted.
CPAP keeps the upper airway open during sleep, which probably helps the valve between the stomach and the food pipe remain closed, which could stop acid from leaking out of the stomach, the authors said.
"This study supports what many of us sleep clinicians know well from experience: Treating sleep apnea with CPAP can dramatically improve gastroesophageal reflux disease [GERD] symptoms," said Dr. Joseph Krainin, a sleep physician and medical review expert at SleepApnea.org. "This study focuses on nocturnal GERD but, in my experience, patients may have significant improvement in daytime GERD as well."
Hill added that the ability of CPAP to relieve acid reflux is another reason to be attentive to sleep apnea therapy, "Particularly if you're having symptoms of reflux, or heartburn or persistent cough, CPAP may help control that along with controlling the other sleep apnea-related problems," he added.
Another expert advises patients to take such symptoms seriously.
"If you have any sort of acid reflux symptoms and hasn't really been getting any better, or if you have any wheezing at night or a productive cough in the morning, it is something that you would definitely talk to your doctor about to determine if [a] sleep study would be indicated to evaluated for sleep apnea," said Dr. Luis Quintero, a pulmonary, critical care and sleep physician at Northwell Health in New Hyde Park, N.Y.
More information
For more on sleep apnea, see the U.S. National Heart, Lung, and Blood Institute.
SOURCES: Thorarinn Gislason, MD, Department of Sleep, Landspitali--National University Hospital of Iceland, ReykjavÃk; Joseph Krainin, MD, sleep physician, medical review expert, SleepApnea.org; David Hill, MD, assistant clinical professor, medicine Yale University School of Medicine, New Haven, Conn., and volunteer medical spokesperson, American Lung Association; Luis Quintero, DO, pulmonary, critical care and sleep physician, Northwell Health, New Hyde Park, N.Y.; ERJ Open Research, Aug. 31, 2023, online
