Department of Pediatrics Medisch Spectrum Twente, P.O. Box 50 000, 7500 KA Enschede, The Netherlands.
Respir Med. 2012 Oct;106(10):1362-8. doi: 10.1016/j.rmed.2012.06.017. Epub 2012 Jul 11.
Methacholine and histamine can lead to inspiratory flow limitation in asthmatic children and adults. This has not been analyzed after indirect airway stimuli, such as exercise. The aim of the study was to analyze airflow limitation after exercise in cold, dry air. 72 asthmatic children with mild to moderate asthma (mean age 13.2 ± 2.2 yrs) performed a treadmill exercise challenge. A fall of >10% in FEV(1) was the threshold for expiratory flow limitation and a fall of >25% of MIF(50) was the threshold for inspiratory flow limitation. The occurrence of wheeze, stridor and cough were quantified before and after exercise. After exercise, the mean fall in FEV(1) was 17.7 ± 14.6%, while the mean fall in MIF(50) was 25.4 ± 15.8%; no correlation was found between fall in FEV(1) and MIF(50) (R(2): 0.04; p = 0.717). 53 of the 72 children showed an inspiratory and/or expiratory airflow limitation. 38% (20/53) of these children showed an isolated expiratory flow limitation, 45% (24/53) showed both expiratory and inspiratory flow limitation and 17% (9/53) showed an isolated inspiratory flow limitation. The fall in FEV(1) peaked 9 min after exercise and correlated to expiratory wheeze. The fall in MIF(50) peaked 15 min after exercise and correlated to inspiratory stridor. The time difference in peak fall between FEV(1) and MIF(50) was statistically significant (5.9 min; p < 0.001, 99% CI: 2.3-9.5 min). In conclusion, this study shows that an exercise challenge in asthmatic children can give rise to inspiratory airflow limitation, which may give rise to asthma like symptoms.
乙酰甲胆碱和组织胺可导致哮喘患儿和成人吸气性气流受限。但是，这在间接气道刺激（如运动）后尚未进行分析。本研究旨在分析寒冷、干燥空气中运动后气流受限的情况。72 例轻至中度哮喘患儿（平均年龄 13.2±2.2 岁）进行了跑步机运动挑战。呼气流量受限的阈值为 FEV1 下降>10%，吸气流量受限的阈值为 MIF（50）下降>25%。在运动前后量化了喘鸣、喉鸣和咳嗽的发生情况。运动后，FEV1 的平均下降率为 17.7±14.6%，而 MIF（50）的平均下降率为 25.4±15.8%；FEV1 下降率与 MIF（50）下降率之间无相关性（R2：0.04；p=0.717）。72 例患儿中有 53 例出现吸气和/或呼气气流受限。其中 38%（20/53）的患儿仅表现为呼气性气流受限，45%（24/53）的患儿表现为呼气和吸气性气流受限，17%（9/53）的患儿仅表现为吸气性气流受限。FEV1 的下降率在运动后 9 分钟达到峰值，与呼气性喘鸣相关。MIF（50）的下降率在运动后 15 分钟达到峰值，与吸气性喉鸣相关。FEV1 和 MIF（50）峰值下降之间的时间差异具有统计学意义（5.9 分钟；p<0.001，99%置信区间：2.3-9.5 分钟）。总之，本研究表明，哮喘患儿的运动挑战可导致吸气性气流受限，这可能导致类似哮喘的症状。
