Tay TunnRen, Choo Xuening, Ihsan Rosna, Toh Hsiao Peng, Wong Hang Siang, Tee Augustine
a Department of Respiratory and Critical Care Medicine , Changi General Hospital , Singapore , Singapore.
J Asthma. 2017 Dec;54(10):1026-1032. doi: 10.1080/02770903.2017.1299756. Epub 2017 Mar 23.
Chronic airflow limitation (CAL) can develop in a subgroup of patients with asthma. Characterising these patients is important because reduced lung function is a risk factor for adverse asthma outcomes. We hypothesised that heterogeneity in patients with CAL may be influenced by age at asthma onset. We first compared never-smoking asthma patients with and without CAL, and subsequently examined the differences between patients with late and early-onset asthma within the CAL cohort.
Patients seen in our hospital's respiratory clinic between 1 Jan 2015 and 31 December 2015 were recruited to the study. CAL was defined as post-bronchodilator forced expiratory volume in 1 second (FEV1)<80% predicted, in the presence of post-bronchodilator ratio <70%. Variables independently associated with CAL were determined using a multivariate logistic regression model. Comparisons between patients with late-onset asthma (age ≥18 years) and early-onset asthma were made within the CAL cohort.
247 patients were included in the study. Age was the only variable independently associated with CAL after regression analysis, with an increase in odds of 3.8% (95% CI 0.4-7.3%) for every 1 year increase in age, p = 0.027. 63.2% of patients with CAL had late-onset asthma. Compared to patients with early-onset asthma, those with late-onset asthma had higher fractional exhaled nitric oxide levels (43 ± 32 ppb vs 20 ± 8 pb, p = 0.008).
An increase in age is associated with CAL in never-smoking asthma patients. In addition, age at asthma onset appears to influence airway inflammation in patients with CAL.
慢性气流受限（CAL）可在一部分哮喘患者中出现。对这些患者进行特征描述很重要，因为肺功能下降是哮喘不良结局的一个危险因素。我们推测CAL患者的异质性可能受哮喘发病年龄的影响。我们首先比较了有和没有CAL的不吸烟哮喘患者，随后在CAL队列中检查了迟发型和早发型哮喘患者之间的差异。
招募2015年1月1日至2015年12月31日在我院呼吸科门诊就诊的患者进行研究。CAL定义为支气管扩张剂后1秒用力呼气容积（FEV1）<预测值的80%，且支气管扩张剂后比值<70%。使用多变量逻辑回归模型确定与CAL独立相关的变量。在CAL队列中对迟发型哮喘（年龄≥18岁）和早发型哮喘患者进行比较。
247例患者纳入研究。回归分析后，年龄是与CAL独立相关的唯一变量，年龄每增加1岁，比值增加3.8%（95%CI：0.4 - 7.3%），p = 0.027。63.2%的CAL患者患有迟发型哮喘。与早发型哮喘患者相比，迟发型哮喘患者呼出一氧化氮分数水平更高（43±32 ppb对20±8 ppb，p = 0.008）。
年龄增加与不吸烟哮喘患者的CAL相关。此外，哮喘发病年龄似乎影响CAL患者的气道炎症。
