摘要目的:建立支气管哮喘(哮喘)患儿肺功能长期变化的发展轨迹，确定哮喘患儿出现长期肺功能损伤的危险因素。方法:采用回顾性队列研究，纳入2019年1月至12月在首都儿科研究所附属儿童医院定期随诊，并完成肺功能检测的14岁以上哮喘患儿，收集其肺功能资料及临床信息。采用潜变量增长模型(LCGM)拟合哮喘患儿肺功能发展轨迹，建立不同的轨迹组，组间比较采用 t检验、方差分析或 χ2检验，确定肺功能长期变化危险因素采用多分类 Logistic回归分析。 结果:共纳入哮喘患儿173例，年龄6~17岁，获得肺功能测定1 160例次。拟合4条1秒率(FEV 1/FVC)潜分类轨迹：持续高水平组、高于平均水平组、低于平均水平组、持续低水平组，其病例数分别为27例(15.6%)、66例(38.1%)、66例(38.1%)、14例(8.1%)。不同轨迹组患儿的FEV 1/FVC在每一年龄组间的差异均有统计学意义(均 P<0.05)。持续高水平组各年龄段的FEV 1/FVC均在90%以上，其余各轨迹组FEV 1/FVC随年龄变化整体呈下降趋势，低于平均水平组的FEV 1/FVC在青春期后下降至80%以下；持续低水平组的FEV 1/FVC均值在学龄期后即下降至80%以下，至青春期接近70%。最大用力呼气中段流量(MMEF)的轨迹和波动情况与FEV 1/FVC相似。危险因素分析显示，与持续高水平组相比，典型哮喘患儿肺功能轨迹处于低于平均水平组的风险是咳嗽变异性哮喘患儿的11.940倍( P＝0.008)；多重致敏患儿的肺功能轨迹处于低于平均水平组的风险是单一致敏的7.462倍( P＝0.015)；未规律用药患儿肺功能处于持续低水平组的风险是规律用药者的6.337倍( P＝0.035)；男童肺功能轨迹处于低于平均水平组的风险是女童的6.186倍( P＝0.002)。 结论:6~17岁哮喘患儿的长期肺功能变化可确定4条不同轨迹：持续高水平、高于平均水平、低于平均水平、持续低水平；近半数患儿的长期肺功能轨迹处于低水平，较多患儿在青春期，少数患儿在学龄期出现持续性气流受限；典型哮喘、多重致敏、未规律用药、男性是哮喘患儿长期肺功能降低的危险因素。

abstractsObjective:To establish the long-term trajectories of lung function in children with bronchial asthma (asthma) and explore the risk factors of persistent pulmonary dysfunction.Methods:A retrospective cohort study was conducted.Children with asthma aged above 14 years who had been followed up regularly and completed pulmonary function testing in Children′s Hospital of Capital Institute of Pediatrics were enrolled in the study from January to December 2019.Their lung function data and clinical information were collected.The latent class growth model (LCGM) was used to fit the change of lung function in children with asthma, and different trajectory groups were established.Comparison between groups was performed by t-test, ANOVA or Chi- square test.The risk factors for the lung function trajectory were analyzed by the multivariate Logistic regression method. Results:A total of 173 children with asthma, aged from 6 to 17, were enrolled, and 1 160 lung function tests were completed.Four forced expiratory volume in the first second/forced vital capacity (FEV 1/FVC) latent class trajectory groups were established, including persistent high level [27 cases (15.6%)], above average level [66 cases (38.1%)], below average level [66 cases (38.1%)], and persistent low level [14 cases (8.1%)]. In all the 4 different trajectory groups, the FEV 1/FVC values were significantly different among patients of different ages (all P<0.05). The FEV 1/FVC values of patients at all ages in the persistent high level group were above 90%.The FEV 1/FVC values of patients in other 3 level groups decreased as a whole as the age increased.FEV 1/FVC of patients in the persistent low level group decreased to below 80% when they entered the school age period and approached 70% in adolescence.The trajectory and fluctuation of maximal midexpiratory flow (MMEF), which represents the small airway function, were similar to those of FEV 1/FVC.Risk factor analysis showed that the risk of lung function decreasing below the average level in children with typical asthma was 11.940 times higher than that in children with cough variant asthma ( P=0.008). The risk of lung function deteriorating to below the average level in children with multiple allergen sensitivities was 7.462 times higher than that in children with single allergen sensitivity ( P=0.015). Children taking drugs irregularly were 6.337 times more likely to suffer persistent low lung function than children taking drugs regularly ( P=0.035). Boys were 6.186 times more likely to suffer a lung function reduction to below the average level than girls ( P=0.002). Conclusions:Four long-term trajectories of lung function in asthmatic children aged 6 to 17 years can be established: persistent high level, above average level, below average level and persistent low level.The long-term lung function of nearly a half of the asthmatic children is below the average level.Many children develop persistent airflow limitation in adolescence, and few at school age.Typical asthma, multiple allergen sensitivities, irregular medication and boy were the risk factors of long-term lung function reduction.