van Veen I H, Ten Brinke A, Sterk P J, Sont J K, Gauw S A, Rabe K F, Bel E H
Dept of Pulmonology, Medisch Spectrum Twente, Postbus 50000, 7500 KA Enschede, The Netherlands.
Eur Respir J. 2008 Aug;32(2):344-9. doi: 10.1183/09031936.00135907. Epub 2008 May 28.
A subset of patients with asthma is known to have progressive loss of lung function despite treatment with corticosteroids. The aim of the present study was to identify risk factors of decline in forced expiratory volume in one second (FEV(1)) in patients with difficult-to-treat asthma. In total, 136 nonsmoking patients with difficult-to-treat asthma were recruited between 1998 and 1999. Follow-up assessment was performed 5-6 yrs later in 98 patients. The predictive effect of clinical characteristics and inflammatory markers were analysed at baseline (asthma onset and duration, atopy, airway hyperresponsiveness, blood and sputum eosinophils, and the fraction of nitric oxide in exhaled air (F(eNO))) on subsequent decline in post-bronchodilator FEV(1). Patients with high F(eNO) (> or =20 ppb) had an excess decline of 40.3 (95% confidence interval (CI) 7.3-73.2) mL.yr(-1) compared to patients with low F(eNO). F(eNO) > or =20 ppb was associated with a relative risk of 1.9 (95% CI, 1.1-2.6) of having an accelerated (> or =25 mL.yr(-1)) decline in FEV(1). In patients with baseline FEV(1) > or =80% of predicted, this relationship was even stronger: 90 versus 29% had accelerated decline in FEV(1) (F(eNO) > or =20 ppb versus F(eNO) <20 ppb respectively; relative risk 3.1 (95% CI, 1.7-3.4). Exhaled nitric oxide is a predictor of accelerated decline in lung function in patients with difficult-to-treat asthma, particularly if forced expiratory volume in one second is still normal.
已知一部分哮喘患者尽管接受了皮质类固醇治疗，肺功能仍会逐渐丧失。本研究的目的是确定难治性哮喘患者一秒用力呼气容积（FEV₁）下降的危险因素。1998年至1999年期间，共招募了136例不吸烟的难治性哮喘患者。5至6年后，对98例患者进行了随访评估。分析了基线时（哮喘发作和病程、特应性、气道高反应性、血液和痰液嗜酸性粒细胞以及呼出气体中一氧化氮分数（F(eNO)））临床特征和炎症标志物对支气管扩张剂后FEV₁随后下降的预测作用。与F(eNO)低的患者相比，F(eNO)高（≥20 ppb）的患者每年FEV₁额外下降40.3（95%置信区间（CI）7.3 - 73.2）mL。F(eNO)≥20 ppb与FEV₁加速下降（≥25 mL·yr⁻¹）的相对风险为1.9（95% CI，1.1 - 2.6）相关。在基线FEV₁≥预测值80%的患者中，这种关系更强：分别有90%和29%的患者FEV₁加速下降（F(eNO)≥20 ppb与F(eNO)<20 ppb；相对风险3.1（95% CI，1.7 - 3.4）。呼出一氧化氮是难治性哮喘患者肺功能加速下降的预测指标，特别是在一秒用力呼气容积仍正常的情况下。
