Visitsunthorn Nualanong, Mahawichit Nawinda, Maneechotesuwan Kittipong
Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Respirology. 2017 Jan;22(1):71-77. doi: 10.1111/resp.12857. Epub 2016 Jul 20.
Fractional exhaled nitric oxide (FeNO) has been used as a marker for airway inflammation. We evaluated the association between FeNO levels and asthma exacerbations (AEs) in Thai children and young adults.
This was a prospective cohort study in patients with atopic asthma aged 7-20 years. Asthma control level and management were evaluated every 3 months for 1 year. Spirometry and FeNO measurements were performed at baseline, and 6 and 12 months.
In all, 70 patients (median age: 12.6 (7.2-19.8) years) were enrolled, of whom 18% had an AE during the study period. Median FeNO levels were significantly higher in patients with an AE than in those without an AE (35.6 ppb vs 16.5 ppb; P = 0.012). FeNO of 31 ppb provided optimal sensitivity (92.3%) and specificity (75.4%) for AE prediction. Sensitivity and specificity of FeNO levels were higher than those of forced expiratory volume in 1 s and forced expiratory flow at 25-75% of forced vital capacity bronchodilator reversibility for the prediction of an AE, but the difference was not significant (P = 0.121). None of the patients with FeNO level of 0-20 ppb had an AE within 12 months. Percentage of patients with FeNO of 21-40 ppb who suffered an AE was 20% and 30% at 6 and 12 months, respectively.
The optimal cut-off point of FeNO level for the prediction of AE is 31 ppb. AE within the next 12 months was significantly more common in patients with higher FeNO levels and in patients with a higher rate of previous 12-month exacerbations.
呼出一氧化氮分数（FeNO）已被用作气道炎症的标志物。我们评估了泰国儿童和年轻人中FeNO水平与哮喘急性发作（AE）之间的关联。
这是一项针对7至20岁特应性哮喘患者的前瞻性队列研究。对哮喘控制水平和管理情况进行为期1年、每3个月一次的评估。在基线、6个月和12个月时进行肺功能测定和FeNO测量。
共纳入70例患者（中位年龄：12.6（7.2 - 19.8）岁），其中18%在研究期间发生了AE。发生AE的患者的中位FeNO水平显著高于未发生AE的患者（35.6 ppb对16.5 ppb；P = 0.012）。FeNO为31 ppb时对AE预测具有最佳敏感性（92.3%）和特异性（75.4%）。FeNO水平的敏感性和特异性高于第1秒用力呼气量以及用力肺活量25% - 75%时的用力呼气流量支气管扩张剂可逆性对AE的预测，但差异不显著（P = 0.121）。FeNO水平为0 - 20 ppb的患者在12个月内均未发生AE。FeNO为21 - 40 ppb的患者在6个月和12个月时发生AE的比例分别为20%和30%。
预测AE的FeNO水平最佳切点为31 ppb。FeNO水平较高以及前12个月急性发作率较高的患者在接下来12个月内发生AE的情况显著更常见。
