A new link has been established between air pollution and sleep disordered breathing by scientists.
Antonella Zanobetti, Ph.D., Susan Redline, MD, MPH, Diane Gold, M.D., M.P.H. and colleagues conducted a study amongst 6,000 participants between 1995 and 1998 wherein they studied the link between air pollution levels, temperature increases and sleep-disordered breathing.
"Our hypothesis was that elevation in ambient air pollution would be associated with an increased risk of SDB and nocturnal hypoxia, as well as with reduced sleep quality," said Zanobetti.
To examine the role of seasons, they performed a separate analysis, adding the interaction of season with the level of air pollution in the form of particulate matter under 10 5m, which is commonly associated with traffic.
"We found novel evidence for pollution and temperature effects on sleep-disordered breathing," said Zanobetti.
"Increases in apnea or hypopnea...were associated with increases in short-term temperature over all seasons, and with increases in particle pollution levels in the summer months.
"Particles may influence sleep through effects on the central nervous system, as well as the upper airways. Poor sleep [associated with poor health outcomes] may disproportionately afflict poor urban populations. Our findings suggest that one mechanism for poor sleep and sleep health disparities may relate to environmental pollution levels."
Over all seasons, the researchers found that short-term elevations in temperature were associated with increased in Respiratory Disturbance Index (RDI), which was used to gauge the severity of SDB.
John Heffner, M.D., past president of the American Thoracic Society observed, "This study gains even greater importance as scientists increasingly demonstrate the critical importance of sleep to health and well being. SDB increases risks for cardiovascular disease, strokes and other major health conditions. Air pollution is an independent contributor to most of these disorders and may produce its negative health effects by promoting SDB as an intermediary step in the pathway toward disease."
The study appears online ahead of the print edition of the American Journal of Respiratory and Critical Care Medicine on the American Thoracic Society's Web site.