支气管哮喘患者呼出气一氧化氮与小气道功能的相关性及其影响因素

Correlation between fractional exhaled nitric oxide and small airway function in patients with bronchial asthma and its influencing factors

目的探讨初次诊断成人支气管哮喘(以下简称哮喘)患者呼出气一氧化氮(FeNO)与小气道功能间的相关性,以及吸烟、过敏性鼻炎对FeNO的影响。方法选择2016年9月1日—11月30日于上海交通大学附属第一人民医院呼吸科门诊就诊的成人哮喘患者,按入选和排除标准纳入受试者42例。进行FeNO测定和嗜酸性粒细胞相对值(Eos%)计数;检测肺功能,主要记录第1秒用力呼气容积(FEV_1)占预计值的百分比(FEV_1%)、最大中期呼气流量(MMEF);检测脉冲震荡肺功能(IOS),主要记录频率在5Hz与20Hz时的气道阻抗差值(R5-R20)。分析FeNO与小气道功能的相关性,以及吸烟、过敏性鼻炎对FeNO的影响。结果哮喘患者的FeNO与Eos%、MMEF、FEV_1%均呈正相关(r值分别为0.433、0.399、0.315,P值分别为0.004、0.009、0.043),与R5-R20不相关(P>0.05);MMEF与R5-R20呈负相关(r=-0.501,P=0.001)。合并过敏性鼻炎的哮喘患者(16例)的FeNO与Eos%呈正相关(r=0.585,P=0.002),与FEV_1%、MMEF、R5-R20均不相关(P值均>0.05);无过敏性鼻炎的哮喘患者(26例)的FeNO与FEV_1、MMEF呈正相关(r值分别为0.505、0.431,P值分别为0.009、0.027),与Eos%、R5-R20不相关(P值均>0.05)。吸烟哮喘患者(14例)的FeNO与其他肺功能、小气道功能指标均不相关(P值均>0.05);不吸烟哮喘患者(28例)的FeNO与Eos%、FEV_1、MMEF均呈正相关(r值分别为0.562、0.572、0.485,P值分别为0.002、0.002、0.009),与R5-R20不相关(P>0.05)。FeNO联合MMEF诊断哮喘小气道功能异常的ROC曲线的AUC(AUC为0.967,95%CI为0.901~1.033,P=0.002)显著大于MMEF(AUC为0.954,95%CI为0.866~1.042,P=0.003)和FeNO联合R5-R20(AUC为0.849,95%CI为0.691~1.007,P=0.022)。结论哮喘患者的FeNO水平对评估哮喘患者小气道功能障碍有一定临床价值,结合MMEF评价意义更高;FeNO水平在不吸烟和不合并过敏性鼻炎的哮喘患者中更有诊断意义。

Objective To explore the correlation between the fractional exhaled nitric oxide （FeNO~） and small airway function in adults with bronchial asthma at the first diagnosis and the effects of smoking and allergic rhinitis on FeNO. Methods According to the inclusion and exclusion criteria, a total of 42 adult asthma patients admitted to the Shanghai General Hospital from September 1, 2016 to November 30, 2016 were enrolled in this study. Their FeNO and eosinophil relative value （Eos%） count were measured. Meanwhile, the pulmonary function was detected, including the percentage of forced expiratory volume at 1 second （FEV1） in the predicted value （FEV % ） and maximum mid-expiratory flow （MMEF）. The airway impedance value of frequency at 5 Hz and 20 Hz （R5-R20） was recorded by impulse oscillometry （lOS）. Results FeNO was positively correlated with Eos%,MMEFandFEV1% （r=0.433, P=0.004; r=0.399, P=0.009; r=0.315, P=0.043）, but not significantly correlated with R5-R20 （P〉0.05） ; and there was a significantly negative correlation between MMEF and R5-R20 （r=- 0. 501, P = 0. 001）. In 16 patients combined with allergic rhinitis, there was a significantly positive correlation between FeNO and Eos% （r = 0. 585, P = 0. 002）, while no relationship was found between FeNO with FEV1 % or MMEF, R5-R20 （all P〉0.05）. In 26 patients without allergic rhinitis, FeNO was positively correlated with FEV1 and MMEF （r=0.505, P=0.009; r =0.431, P=0.027）, but not with Eos% and R5-R20 （both P〉 0.05）. In 14 smoking asthmatic patients, FeNO was not correlated with other parameters of lung function or small airway function （all P 〉0. 05）. But FeNO was positively correlated with Eos%, FEV1 and MMEF in 28 non- smoking asthmatic patients （r=0.562, P=0.002% r=0.572, P=0.002; r=0.485, P=0.009）, and no correlation between FeNO and R5-R20 in these patients （P〉0.05）. A receiver operating characteristic （ROO） analysis showed that FeNO combines with MMEF had a greater area under the ROC curve （AUC= 0. 967, 95 % CI =0.901-1.033, P=0.002）than MMEF only （AUC=0.954, 95%CI=0.866-1.042, P=0.003） and FeNO combined withR5-R20 （AU0=0.849, 95%CI=0.691-1.007, P=0.022）. Conclusion FeNO has a certain clinical value in assessing small airway dysfunction in asthmatic patients, and it is more valuable when combines with MMEF. In addition, FeNO may play a more important role in diagnosis of bronchial asthma in patients without smoking and allergic rhinitis.