According to the National Sleep Foundation, about 18 million Americans have sleep apnea.
While several studies have already looked at links between sleep apnea and pneumonia, this latest investigation is the largest to do so. Dr. Vincent Yi-Fong Su, of Taipei Veterans General Hospital in Taiwan, and colleagues selected over 34,000 patients from Taiwan's National Health Insurance Research Database (nearly 7,000 patients with sleep apnea matched to over 27,000 people without sleep apnea). They followed the participants for 11 years, from the beginning of 2000 to the end of 2010, and compared occurrence of pneumonia in the two groups.
Sleep apnea appears to be an independent risk factor for pneumonia They found the group with sleep apnea had a 1.20-fold increase in incident pneumonia, compared with the group without sleep apnea (9.36% developed it in the apnea group versus 7.77% in the controls).
They also noticed that the people who developed pneumonia tended to be older and had more illnesses, such as diabetes, heart disease and dementia. The team concludes that sleep apnea appears to be an "independent risk factor for incident pneumonia," and notes they also found an "exposure-response relation," meaning that patients with more severe sleep apnea appeared to have a higher risk of developing pneumonia than patients with milder forms of the condition.
While they did not explore the mechanisms linking sleep apnea with pneumonia, the researchers suggest it could be that people with sleep apnea are more likely to aspirate liquid from the throat into the lungs. Another reason could be a weaker immune system, which can result from frequently disturbed sleep.
In October 2013, Medical News Today reported another study led by researchers at the University of California Los Angeles that suggested sleep apnea may hold hidden dangers for women. They found women with sleep apnea may appear healthy, but they have subtle symptoms, which means the condition is often misdiagnosed.
Written by Catharine Paddock PhD