Outdoor air pollution is associated with disease severity in α1-antitrypsin deficiency

Abstract

The aim of this study was to determine whether long-term air pollution exposure is associated with clinical phenotype in α1- antitrypsin deficiency. In total, 304 PiZZ subjects underwent full lung function testing and quantitative high-resolution computed tomography to identify the presence and severity of the disease. Mean annual air pollutant data for 2006 was matched to the location of patients' houses and used in regression models to identify phenotypic associations with pollution, controlling for covariates. Relative trends in pollution levels were assessed to validate use of a single year's data to indicate long-term exposure. Pollutant levels correlated significantly with one another, with higher levels of primary particles, SO 2 and NO2 being associated with lower ozone levels. Regression models showed that estimated higher exposure to ozone was associated with worse gas transfer and more severe emphysema. Regression parameters suggested that significance from other pollutants was due to collinearity with ozone. The 2006 pollutant levels showed linear relationships with cumulative years, thus validating the model. Higher exposures to ozone may be associated with worse respiratory status in α1-antitrypsin deficiency, identifying a group susceptible to ambient air pollution.