Department of Paediatrics, Oslo University Hospital, NO-0407 Oslo, Norway.
Am J Respir Crit Care Med. 2012 Sep 15;186(6):493-500. doi: 10.1164/rccm.201112-2235OC. Epub 2012 Jul 12.
Bronchial hyperresponsiveness (BHR) is an important, but not specific, asthma characteristic.
We aimed to assess the predictive value of BHR tested by methacholine and exercise challenge at age 10 years for active asthma 6 years later.
From a Norwegian birth cohort, 530 children underwent methacholine challenge and exercise-induced bronchoconstriction (EIB) test (n = 478) at 10 years and structured interview and clinical examination at age 16 years. The methacholine dose causing 20% reduction in FEV(1) (PD(20)) and the reduction in FEV(1) (%) after a standardized treadmill test were used for BHR assessment. Active asthma was defined with at least two criteria positive: doctor's diagnosis of asthma, symptoms of asthma, and/or treatment for asthma in the last year.
PD(20) and EIB at 10 years of age increased the risk of asthma (β = 0.94 [95% confidence interval (CI), 0.92-0.96] per μmol methacholine and β = 1.10 [95% CI, 1.06-1.15] per %, respectively). Separately the tests explained 10 and 7%, respectively, and together 14% of the variation in active asthma 6 years later. The predicted probability for active asthma at the age of 16 years increased with decreasing PD(20) and increasing EIB. The area under the curve (receiver operating characteristic curves) was larger for PD(20) (0.69; 95% CI, 0.62-0.75) than for EIB (0.60; 95% CI, 0.53-0.67).
BHR at 10 years was a significant but modest predictor of active asthma 6 years later, with methacholine challenge being superior to exercise test.
支气管高反应性（BHR）是一种重要但非特异性的哮喘特征。
我们旨在评估 10 岁时用乙酰甲胆碱和运动激发试验检测到的 BHR 对 6 年后活动性哮喘的预测价值。
来自挪威的一个出生队列，530 名儿童在 10 岁时接受乙酰甲胆碱激发试验和运动诱导的支气管收缩（EIB）试验（n = 478），并在 16 岁时进行结构化访谈和临床检查。使用引起 FEV1 下降 20%的乙酰甲胆碱剂量（PD20）和标准化跑步机试验后 FEV1 下降的百分比来评估 BHR。活动性哮喘的定义是至少有两个标准阳性：医生诊断为哮喘、哮喘症状和/或过去一年中因哮喘进行治疗。
10 岁时的 PD20 和 EIB 增加了哮喘的风险（每增加 1μmol 乙酰甲胆碱，β = 0.94 [95%置信区间（CI），0.92-0.96]；每增加 1%，β = 1.10 [95% CI，1.06-1.15]）。单独来看，这两个测试分别解释了 10%和 7%的 6 年后活动性哮喘的变异，而联合使用则解释了 14%的变异。随着 PD20 的降低和 EIB 的增加，预测 16 岁时发生活动性哮喘的概率也随之增加。PD20 的曲线下面积（接受者操作特征曲线）大于 EIB（PD20：0.69；95%CI，0.62-0.75；EIB：0.60；95%CI，0.53-0.67）。
10 岁时的 BHR 是 6 年后活动性哮喘的一个显著但适度的预测指标，乙酰甲胆碱激发试验优于运动试验。
