Background: 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 FO group had fewer women, lower body mass index (BMI), longer disease duration, higher smoking history rate, allergic family history rate, FeNO level, and lower levels of large airway parameters. The median exposure levels of PM10 and PM2.5 in the severe RO subgroup were both higher than those in the mild-to-moderate RO subgroup on Lag0, 1 and 3, and the median exposure level of PM1 on Lag0 in the severe RO subgroup was significantly higher than that in the mild-to-moderate RO subgroup. Logistic regression modeling indicated exposure to PM2.5 and PM1.0 on Lag0, and PM10 on Lag0-2 were the independent risk factors for hospital admissions for asthma patients with RO. By performing an ROC curve analysis, PM2.5 on Lag0 (AUC = 0.645, p = 0.027) provided a best performance to predict severe asthma exacerbations with RO, with a sensitivity of 36.0% and a specificity of 91.2%.
Conclusion: Short-term exposure to PM10, PM2.5 and PM1 may play a role in exacerbation severity among asthma patients with RO.



中文翻译：

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空气污染物暴露对伴有或不伴有可逆气流阻塞的哮喘患者加重严重程度的影响

背景：可逆性气流阻塞（RO）和固定气流阻塞（FO）是哮喘的两种重要临床表型。然而，空气污染物暴露与两种表型恶化之间的关系尚不清楚。
目的：研究空气污染物暴露对伴有或不伴有 FO 的哮喘患者恶化严重程度的影响。
方法：共纳入 197 名重症哮喘患者，分为两组：FO 组（n=81）和 RO 组（n=116）。我们收集了每个受试者不同滞后天数的人口统计数据、实验室参数、肺功能测试参数以及深圳不同空气颗粒物的日平均浓度。受试者工作特征（ROC）曲线用于确定主要空气污染物对患有 RO 的哮喘患者严重程度的影响。
结果：与 RO 组相比，FO 组女性更少，体重指数（BMI）更低，病程更长，吸烟史率更高，过敏家族史率更高，FeNO 水平更低，大气道参数水平更低。重度 RO 亚组 PM10 和 PM2.5 的中位暴露水平在 Lag0、1 和 3 均高于轻度至中度 RO 亚组，重度 RO 亚组 PM1 在 Lag0 的中位暴露水平显着高于轻度至中度 RO 亚组。Logistic回归模型显示，Lag0时PM2.5和PM1.0暴露，Lag0-2时PM10是RO哮喘患者住院的独立危险因素。通过执行 ROC 曲线分析，Lag0 上的 PM2.5 (AUC = 0.645, p= 0.027) 提供了预测 RO 严重哮喘发作的最佳性能，敏感性为 36.0%，特异性为 91.2%。
结论：短期暴露于 PM10、PM2.5 和 PM1 可能与 RO 哮喘患者的病情加重有关。