For people with both sleep apnea and chronic obstructive pulmonary disease -- otherwise known as "overlap syndrome" -- getting the sleep disorder treated could save their lives, a new study suggests.
Researchers from Brown University found that treatment with continuous positive airway pressure (CPAP, considered the gold standard for sleep apnea treatment) lowers death risk among people with sleep apnea and COPD.
The study, published in the Journal of Clinical Sleep Medicine, is based on data from 10,272 outpatients. Of those people, 3,396 people had COPD or obstructive sleep apnea between 2007 and 2010, and among those, 227 had both conditions. The people with both conditions were treated with CPAP, and researchers kept track of how compliant they were in using the treatment for the first one to three months.
By the end of the study period, 17 people who had both sleep apnea and COPD had died. Researchers found an association between CPAP compliance and risk of dying over the study period. Surprisingly, researchers found that any use of CPAP still helped to lower the risk of death. Age was also identified as an independent predictor of death.
"We were most surprised to find that any level of CPAP use in this cohort, over no use, was associated with some mortality benefit," study researcher Michael L. Stanchina, M.D., who is a clinical assistant professor of medicine at the Alpert Medical School a the university, said in a statement.
A past study on overlap syndrome, published in the Proceedings of the American Thoracic Society, explained that the prevalence of sleep apnea isn't necessarily higher among people with COPD, and that having the two conditions at once is probably just a matter of chance.
CPAP has been shown to decrease the death risk among people with other health conditions, too. A study presented at the ATS 2011 International Conference showed that elderly people's risk of dying from heart-related reasons goes down if they have their sleep apnea treated with CPAP. In addition, a 2009 study in the American Journal of Respiratory and Critical Care Medicine showed that stroke patients with sleep apnea could lower their risk of dying if they receive CPAP treatment.