Fractional exhaled nitric oxide and forced expiratory flow between 25% and 75% of vital capacity in children with controlled asthma

Background Cough variant asthma (CVA), a suggested precursor of standard bronchial asthma (SBA), is characterized by positive bronchial hyperresponsiveness (BHR) and a chronic cough response to bronchodilator that persists for >8 weeks. Objective Airway inflammation, BHR, and airway obstructive damage were analyzed to assess whether CVA represents early or mild-stage SBA. Methods Patients with newly diagnosed CVA (n = 72) and SBA (n = 84) naive to oral or inhaled corticosteroids and without exacerbated asthma were subjected to spirometry, impulse oscillometry, BHR tests, sputum induction, and fractional exhaled nitric oxide measurements. Results In the patients with CVA, spirometry demonstrated higher forced expiratory volume in 1 second (FEV1) to forced vital capacity ratio, FEV1 percent predicted, flow volume at 50% of vital capacity % predicted, and flow volume at 25% of vital capacity % predicted values, and impulse oscillometry demonstrated lower R5–Z20, AX, and Fres, and higher X5 values. In addition, the fractional exhaled nitric oxide and sputum eosinophil numbers were lower and the PC20 was higher than in patients with moderate SBA. However, these factors were similar in the patients with CVA and in the patients with intermittent mild SBA. A significantly smaller proportion of the patients with CVA had increased sputum eosinophils than the patients with intermittent mild SBA (p < 0.0001). However, interestingly, among the patients with CVA, no significant differences in the PC20 values were found between the patients with and those without increased sputum eosinophils. Conclusions All measures of central and peripheral airway obstruction, eosinophilic inflammation, and airway hyperresponsiveness in patients with CVA were milder than in patients with moderate SBA but were similar to those of patients with intermittent mild SBA. In CVA, the BHR was not affected by airway eosinophilic inflammation, which indicated that the very early development of BHR may not always need airway eosinophilic inflammation.

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Fractional exhaled nitric oxide and forced expiratory volume in 1 second/forced vital capacity have predictive value of asthma exacerbation in Korean school children

Asia Pacific Allergy ◽

10.5415/apallergy.2020.10.e7 ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 3

Author(s):

Min-Gyu Kang ◽

Shin-Ae Yoon ◽

Ju-Han Sim ◽

Sung-Il Woo

Keyword(s):

Nitric Oxide ◽

School Children ◽

Forced Vital Capacity ◽

Predictive Value ◽

Asthma Exacerbation ◽

Vital Capacity ◽

Forced Expiratory Volume ◽

Exhaled Nitric Oxide ◽

Fractional Exhaled Nitric Oxide

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Fração Exalada de Óxido Nítrico no Controlo e Abordagem Terapêutica da Asma

Acta Médica Portuguesa ◽

10.20344/amp.2371 ◽

2014 ◽

Vol 27 (1) ◽

pp. 59 ◽

Cited By ~ 1

Author(s):

Bruno Melo ◽

Patrício Costa ◽

Ariana Afonso ◽

Vânia Machado ◽

Carla Moreira ◽

...

Keyword(s):

Nitric Oxide ◽

Asthma Control ◽

Peak Expiratory Flow ◽

Chronic Respiratory Disease ◽

Exhaled Nitric Oxide ◽

Fractional Exhaled Nitric Oxide ◽

Cross Sectional ◽

Asthmatic Children ◽

Bronchial Inflammation ◽

Expiratory Flow

Introduction: Asthma is a chronic respiratory disease characterized by hyper-responsiveness and bronchial inflammation. The bronchial inflammation in these patients can be monitored by measuring the fractional exhaled nitric oxide. This study aims to determine fractional exhaled nitric oxide association with peak expiratory flow and with asthma control inferred by the Global Initiative for Asthma. Material and Methods: Observational, analytical and cross-sectional study of children with asthma, 6-12 years-old, followed in the Outpatient Respiratory Pathology of Braga Hospital. Sociodemographic and clinical information were collected through a questionnaire. fractional exhaled nitric oxide and peak expiratory flow were determined by portable analyzer Niox Mino® and flow meter, respectively. Results: The sample is constituted by 101 asthmatic children, 63 (62.4%) of males and 38 (37.6%) females. The mean age of participants in the sample is 9.18 (1.99) years. The logistic regression performed with the cutoff value obtained by ROC curve, revealed that fractional exhaled nitric oxide (bFENO classes = 0.85; χ2 Wald (1) = 8.71; OR = 2.33; p = 0.003) has a statistical significant effect on the probability of changing level of asthma control. The odds ratio of going from “controlled” to “partly controlled/uncontrolled” is 2.33 per each level of fractional exhaled nitric oxide. Discussion and Conclusion: The probability of an asthmatic children change their level of asthma control, from ‘controlled’ to ‘partly controlled/uncontrolled’, taking into account a change in their fractional exhaled nitric oxide level, increases 133%.

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Fractional exhaled nitric oxide could identify early spirometry change in clinically suspected asthma patients without airway obstruction

European Journal of Inflammation ◽

10.1177/20587392211004110 ◽

2021 ◽

Vol 19 ◽

pp. 205873922110041

Author(s):

Qingbo Gao ◽

Qiaozhen Wu ◽

Fei Li ◽

Cheng Chen

Keyword(s):

Nitric Oxide ◽

Airway Obstruction ◽

Significant Proportion ◽

Exhaled Nitric Oxide ◽

Fractional Exhaled Nitric Oxide ◽

Maximal Expiratory Flow ◽

Increased Risk ◽

Significant Difference ◽

Expiratory Flow ◽

Feno Level

Fractional exhaled nitric oxide (FeNO) has been proposed as a non-invasive biomarker for allergic inflammation seen in asthma. The aim of this study was to assess the ability of FeNO to discriminate spirometry and lung volume measurements between those with and without airway obstruction among subjects with clinically suspected asthma. A retrospective study was conducted. Diagnostic evaluations including spirometry and FeNO testing (NO electrochemical equipment: NIOX VERO; Aerocrine AB, Solna, Sweden) were performed in all subjects. Airway obstruction was defined according to the Standardization of Spirometry of the American Thoracic Society (ATS)/European Respiratory Society (ERS), and 2014 recommendations of the Chinese National Guidelines of Pulmonary Function Test. It was used the Student t test for analysis of continuous variables and the χ2 test for analysis of discrete variables including FeNO levels and lung function metrics. Of the 138 subjects with clinically suspected asthma, airway obstruction was found in 61. There was no significant difference in the mean FeNO levels among subjects with or without airway obstruction ( p = 0.241) among un-selected subjects. Likewise, there was no difference in the FeNO levels between aged (>50 years) and younger subjects (⩽50 years) ( p = 0.804). A significant proportion of subjects had a normal FeNO level (<25 part per billion, ppb) in spite of having airway obstruction (39/138), 25 had an elevated FeNO level (⩾25 ppb) in spite of having no airway obstruction (25/138). Additionally, the airway-obstructed subjects with increased FeNO level had comparable spirometry to those with normal FeNO level ( p > 0.05). However, among subjects without airway obstruction, the forced expiratory volume in 1 s (FEV1)/predicted (pred), maximal expiratory flow at 25% of forced vital capacity (FVC) (MEF25%)/pred, maximal expiratory flow at 50% of FVC (MEF50%)/pred and maximum mid-expiratory flow (MMEF)/pred were significantly lower in the FeNO ⩾ 25 ppb group compared to those in the FeNO < 25 ppb group. These analyses indicated that increased FeNO levels could help to determinate early spirometry change within clinically suspected asthma subjects without airway obstruction. It is highlighted the importance of FeNO as a phenotype associated with an increased risk of airway obstruction in some subjects in this study.

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