• Teresa To, Jingqin Zhu, Kristian Larsen, Jacqueline Simatovic, Laura Feldman, Kandace Ryckman, Andrea Gershon, M Diane Lougheed, Christopher Licskai, Hong Chen, Paul J Villeneuve, Eric Crighton, Yushan Su, Mohsen Sadatsafavi, Devon Williams, Christopher Carlsten, and Canadian Respiratory Research Network.
• 1 Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada.
• Am. J. Respir. Crit. Care Med. 2016 Aug 15; 194 (4): 429-38.

RationaleIndividuals with asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS), have more rapid decline in lung function, more frequent exacerbations, and poorer quality of life than those with asthma or COPD alone. Air pollution exposure is a known risk factor for asthma and COPD; however, its role in ACOS is not as well understood.ObjectivesTo determine if individuals with asthma exposed to higher levels of air pollution have an increased risk of ACOS.MethodsIndividuals who resided in Ontario, Canada, aged 18 years or older in 1996 with incident asthma between 1996 and 2009 who participated in the Canadian Community Health Survey were identified and followed until 2014 to determine the development of ACOS. Data on exposures to fine particulate matter (PM2.5) and ozone (O3) were obtained from fixed monitoring sites. Associations between air pollutants and ACOS were evaluated using Cox regression models.Measurements And Main ResultsOf the 6,040 adults with incident asthma who completed the Canadian Community Health Survey, 630 were identified as ACOS cases. Compared with those without ACOS, the ACOS population had later onset of asthma, higher proportion of mortality, and more frequent emergency department visits before COPD diagnosis. The adjusted hazard ratios of ACOS and cumulative exposures to PM2.5 (per 10 μg/m(3)) and O3 (per 10 ppb) were 2.78 (95% confidence interval, 1.62-4.78) and 1.31 (95% confidence interval, 0.71-2.39), respectively.ConclusionsIndividuals exposed to higher levels of air pollution had nearly threefold greater odds of developing ACOS. Minimizing exposure to high levels of air pollution may decrease the risk of ACOS.

42 keywords...

hide…