Ko Fanny Wai San, Chan Ka Pang, Ng Joyce Ka Ching, Ngai Jenny C L, Yip Wing Ho, Lo Rachel Lai Ping, Chan Tat On, Hui David Shu Cheong
Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.
The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, People's Republic of China.
J Asthma Allergy. 2023 Jul 14;16:725-734. doi: 10.2147/JAA.S417117. eCollection 2023.
Previous studies found that the fractional nitric oxide concentration in exhaled breath (FeNO) levels in healthy Chinese adults was higher than in White adults. More understanding of serial changes of FeNO levels with asthma control in a real-life clinical setting would be important to explore the utility of this biomarker in routine asthma management. This study assessed the FeNO levels of Chinese asthma subjects with different levels of asthma control and the serial changes with respect to the changes in asthma control over 1 year.
A 12-month prospective study (subjects recruited between November 2019 and January 2021) with serial measurement of FeNO levels at baseline, 4, 8 and 12 months. Asthma control was assessed by the Global Initiative for Asthma classification, Asthma Control Test (ACT) and Asthma Control Questionnaire (ACQ).
Altogether, 136 subjects (mean age 51.51±15.09 years, 46[33.8%] male) had successful baseline FeNO measurements. At baseline, the FeNO levels did not show a statistically significant difference for controlled, partly controlled and uncontrolled asthma according to GINA classification, ACT and ACQ. FeNO levels decreased with improving asthma control and stayed at similar levels with unchanged or worsening asthma control for all subjects. For subjects with baseline blood eosinophil levels ≥300 cells/µL(n=59), FeNO levels decreased with improving asthma control, stayed similar without change for asthma control and increased with worsening asthma control. Receiver operating characteristic (ROC) analysis with the highest area under curve (AUC) for changes in FeNO levels for improving asthma control was between ≤ -10 to -25 ppb at various time points in the 12-month study.
Changes in FeNO levels over time were associated with changes in clinical asthma control, particularly in those with higher blood eosinophil count and are likely more useful than a single time point measurement in managing asthma.
先前的研究发现，健康中国成年人呼出气中一氧化氮分数浓度（FeNO）水平高于白人成年人。在现实临床环境中，进一步了解FeNO水平随哮喘控制情况的连续变化，对于探索该生物标志物在哮喘常规管理中的效用具有重要意义。本研究评估了不同哮喘控制水平的中国哮喘患者的FeNO水平，以及1年内哮喘控制变化时的连续变化情况。
一项为期12个月的前瞻性研究（2019年11月至2021年1月招募受试者），在基线、4个月、8个月和12个月时连续测量FeNO水平。通过全球哮喘防治创议分类、哮喘控制测试（ACT）和哮喘控制问卷（ACQ）评估哮喘控制情况。
共有136名受试者（平均年龄51.51±15.09岁，46名[33.8%]男性）成功进行了基线FeNO测量。根据全球哮喘防治创议分类、ACT和ACQ，在基线时，控制良好、部分控制和未控制的哮喘患者的FeNO水平在统计学上无显著差异。所有受试者的FeNO水平随着哮喘控制的改善而降低，在哮喘控制不变或恶化时保持在相似水平。对于基线血嗜酸性粒细胞水平≥300个细胞/微升的受试者（n=59），FeNO水平随着哮喘控制的改善而降低，在哮喘控制不变时保持相似，在哮喘控制恶化时升高。在为期12个月的研究中，不同时间点FeNO水平改善哮喘控制变化的曲线下面积（AUC）最高的受试者工作特征（ROC）分析显示，其范围在≤-10至-25 ppb之间。
FeNO水平随时间的变化与临床哮喘控制的变化相关，特别是在血嗜酸性粒细胞计数较高的患者中，并且在哮喘管理中可能比单次测量更有用。
