Park Han-Ki, Jung Jae-Woo, Cho Sang-Heon, Min Kyung-Up, Kang Hye-Ryun
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea ; Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea.
Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea ; Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
PLoS One. 2014 Jan 30;9(1):e87155. doi: 10.1371/journal.pone.0087155. eCollection 2014.
Exercise-induced bronchoconstriction (EIB) was recently classified into EIB alone and EIB with asthma, based on the presence of concurrent asthma.
Differences between EIB alone and EIB with asthma have not been fully described.
We retrospectively reviewed who visited an allergy clinic for respiratory symptoms after exercise and underwent exercise bronchial provocation testing. More than a 15% decrease of forced expiratory volume in 1 second (FEV1) from baseline to the end of a 6 min free-running challenge test was interpreted as positive EIB.
EIB was observed in 66.9% of the study subjects (89/133). EIB-positive subjects showed higher positivity to methacholine provocation testing (61.4% vs. 18.9%, p<0.001) compared with EIB-negative subjects. In addition, sputum eosinophilia was more frequently observed in EIB-positive subjects than in EIB-negative subjects (56% vs. 23.5%, p = 0.037). The temperature and relative humidity on exercise test day were significantly related with the EIB-positive rate. Positive EIB status was correlated with both temperature (p = 0.001) and relative humidity (p = 0.038) in the methacholine-negative EIB group while such a correlation was not observed in the methacholine-positive EIB group. In the methacholine-positive EIB group the time to reach a 15% decrease in FEV1 during exercise was significantly shorter than that in the methacholine-negative EIB group (3.2±0.7 min vs. 8.6±1.6 min, p = 0.004).
EIB alone may be a distinct clinical entity from EIB with asthma. Conditions such as temperature and humidity should be considered when performing exercise tests, especially in subjects with EIB alone.
运动诱发性支气管收缩（EIB）最近根据是否并发哮喘被分为单纯性EIB和合并哮喘的EIB。
单纯性EIB与合并哮喘的EIB之间的差异尚未得到充分描述。
我们回顾性分析了因运动后出现呼吸道症状而前往过敏诊所就诊并接受运动支气管激发试验的患者。在6分钟自由跑步激发试验中，1秒用力呼气量（FEV1）较基线下降超过15%被判定为EIB阳性。
66.9%的研究对象（89/133）出现EIB。与EIB阴性患者相比，EIB阳性患者对乙酰甲胆碱激发试验的阳性率更高（61.4%对18.9%，p<0.001）。此外，EIB阳性患者痰液嗜酸性粒细胞增多的情况比EIB阴性患者更常见（56%对23.5%，p = 0.037）。运动试验当天的温度和相对湿度与EIB阳性率显著相关。在乙酰甲胆碱阴性的EIB组中，EIB阳性状态与温度（p = 0.001）和相对湿度（p = 0.038）均相关，而在乙酰甲胆碱阳性的EIB组中未观察到这种相关性。在乙酰甲胆碱阳性的EIB组中，运动期间FEV1下降15%所需的时间明显短于乙酰甲胆碱阴性的EIB组（3.2±0.7分钟对8.6±1.6分钟，p = 0.004）。
单纯性EIB可能是一种与合并哮喘的EIB不同的临床实体。进行运动试验时应考虑温度和湿度等因素，尤其是对于单纯性EIB患者。
