Kalliola Satu, Malmberg L Pekka, Pelkonen Anna S, Mäkelä Mika J
Department of Allergology, University of Helsinki, Helsinki University Central Hospital, Helsinki, Finland.
Department of Allergology, University of Helsinki, Helsinki University Central Hospital, Helsinki, Finland.
Respir Med. 2016 Feb;111:16-20. doi: 10.1016/j.rmed.2015.12.006. Epub 2015 Dec 19.
Frequency dependence of resistance (R5-20) assessed by impulse oscillometry (IOS) is suggested to be a measure of small airways. Small airways involvement during induced bronchoconstriction has been shown to reflect severity of asthma in adults.
Our aim was to evaluate if methacholine (Mch) induced changes in R5-20 are associated with the severity of exercise induced bronchoconstriction (EIB) in young children.
A total of 109 children aged 3-8 years were studied, 95 with obstructive symptoms and 14 in good health, to assess small airways function during a Mch challenge. R5-20 and other IOS resistance and reactance parameters were measured at baseline and after the Mch challenge. In a standardized exercise test, the children were grouped according to the severity of EIB expressed as the percentage increase in resistance at 5 Hz (ΔR5) after exercise, indicating either no EIB (ΔR5 < 40%, n = 84), moderate EIB (ΔR5 40-80%, n = 13) and severe EIB (ΔR5 > 80%, n = 12).
The baseline R5-20 was not associated with the severity of EIB, but during Mch induced bronchoconstriction the change in R5-20 was significantly higher in children with severe EIB (2.61 fold increase) than in children with moderate EIB (1.48) or no EIB (1.74, p = 0.036). No significant associations were found in changes of other IOS parameters. The children with severe EIB also used more short-acting beta-agonists during the past two months than the other two groups (p < 0.001).
Frequency dependence of resistance (R5-20) measured by IOS during the Mch induced bronchoconstriction and more frequent use of beta-agonists are associated with severe EIB in young children.
脉冲振荡法（IOS）评估的电阻抗频率依赖性（R5-20）被认为是小气道的一项指标。已表明，诱导支气管收缩期间小气道受累情况可反映成人哮喘的严重程度。
我们的目的是评估乙酰甲胆碱（Mch）诱导的R5-20变化是否与幼儿运动诱发性支气管收缩（EIB）的严重程度相关。
共研究了109名3至8岁的儿童，其中95名有阻塞性症状，14名健康状况良好，以评估Mch激发试验期间的小气道功能。在基线和Mch激发试验后测量R5-20以及其他IOS电阻抗和电抗参数。在标准化运动试验中，根据运动后5Hz时电阻增加百分比（ΔR5）所表示的EIB严重程度对儿童进行分组，分别为无EIB（ΔR5 < 40%，n = 84）、中度EIB（ΔR5 40-80%，n = 13）和重度EIB（ΔR5 > 80%，n = 12）。
基线R5-20与EIB严重程度无关，但在Mch诱导的支气管收缩期间，重度EIB儿童的R5-20变化（增加2.61倍）显著高于中度EIB儿童（1.48倍）或无EIB儿童（1.74倍，p = 0.0３6）。未发现其他IOS参数变化存在显著关联。在过去两个月中，重度EIB儿童使用短效β-激动剂的频率也高于其他两组（p < 0.001）。
Mch诱导支气管收缩期间通过IOS测量的电阻抗频率依赖性（R5-20）以及更频繁使用β-激动剂与幼儿重度EIB相关。
