Effects of Air Pollutant Exposure on Exacerbation Severity in Asthma Patients with or without Reversible Airflow Obstruction

Wei Fang,1,* Yu Zhang,1,* Sinian Li,1,* Aiming Liu,2,* Yin Jiang,2 Dandan Chen,1 Binbin Li,3 Can Yao,3 Rongchang Chen,1 Fei Shi3 1Key Laboratory of Shenzhen Respiratory Diseases, Institute of Shenzhen Respiratory Diseases, Shenzhen People’s Hospital (The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College of Jinan University), Shenzhen, Guangdong, People’s Republic of China; 2Shenzhen National Climate Observatory, Meteorological Bureau of Shenzhen Municipality, Shenzhen Key Laboratory of Severe Weather in South China, Shenzhen, Guangdong, People’s Republic of China; 3Emergency Department, Institute of Shenzhen Respiratory Diseases, Shenzhen People’s Hospital (The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College of Jinan University), Shenzhen, Guangdong, People’s Republic of China*These authors contributed equally to this workCorrespondence: Rongchang Chen; Fei Shi Email chenrc@vip.163.com; shi.fei@szhospital.comBackground: Reversible airflow obstruction (RO) and fixed airflow obstruction (FO) are two important clinical phenotypes of asthma. However, the relationship between air pollutant exposure and exacerbation of the two phenotypes is unknown.Objective: To study the effects of air pollutant exposure on exacerbation severity in asthma patients with or without FO.Methods: A total of 197 severe asthma patients were enrolled, and divided into two groups: the FO group (n=81) and the RO group (n=116). We collected the demographic data, laboratory parameters, pulmonary function test parameters, and the daily average concentrations of different air particles in Shenzhen on the different lag days of each subject. The receiver operating characteristic (ROC) curve was used to identify the effects of major air pollutants on the severity of asthma patients with RO.Results: Compared with the RO group, the F