The negative impact of air pollution on respiratory diseases such as chronic obstructive lung disease (COPD) and asthma and cardiovascular disease is well established by epidemiological studies. Now, new data show that air pollution also may contribute to obstructive sleep apnea.
In a study recently published in the Annals of the American Thoracic Society, investigators report on the effects of ambient air pollution on obstructive sleep apnea and sleep disruption (Ann Am Thorac Soc. Published online December 20, 2018; doi: 10.1513/AnnalsATS.201804-248OC). In particular, the investigators looked at the link between mean annual and five-year exposure levels to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and oxides of nitrogen (NOx) and obstructive sleep apnea.
Investigators analyzed data from a sample of participants (n=1974) enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA) and MESA’s Sleep and Air Pollution studies. Of the 1974 participants, 46% were male, 36% White, 28% Black, 28% Hispanic, and 12% Asian, with a mean age of 68.4 years and mean BMI of 28.7 kg/m2. Among the participants, 48% had sleep apnea and 25% had reduced sleep efficiency.
To evaluate sleep, each participant completed an in-home full polysomnography and seven days of wrist actigraphy. Moderate to severe sleep apnea was indicated by an AHI >15 and reduced sleep efficiency by <88% (corresponding to the lowest 25% percentile of the average seven-day actigraphy reading). Exposure to air pollution was calculated using a number of measurements, including data collected from community and Air Quality System monitoring sites.
After adjusting for demographics, co-morbidities, socioeconomic factors, and site, the authors found that the odds of having sleep apnea increased by 39% for each 10 parts per billion increase in yearly NO2 and by 60% for each 5 microgram per cubic meter (ug/m3) of yearly PM2.5 exposure.
“Among people of the same age, weight, race/ethnicity, and medical problems, those exposed to higher pollution levels had greater odds of having moderate to severe sleep apnea,” said the lead author of the study, Martha E. Billings, MD, associate professor of pulmonary, critical care, and sleep medicine at the University of Washington in Seattle, adding that sleep apnea risk may increase with exposure to even slightly higher levels of air pollution over time.
Clinicians should “keep in mind chronic exposure to air pollution as a potential contributor to sleep apnea,” she said.