Correlation between fractional exhaled nitric oxide and Asthma Control Test score and spirometry parameters in on-treatment- asthmatics in Ho Chi Minh City

Abstract

Background: Although fractional exhaled nitric oxide (FeNO) is a reliable and easily applied marker of airway inflammation in asthma, the relationship between FeNO and indicators of asthma control [Asthma Control Test (ACT) score] and/or severity (spirometry parameters) remains unclear. This study aims to determine possible correlations between FeNO and ACT score; and between FeNO and spirometry parameters. Methods: A cross-sectional study with convenience sampling was conducted among ambulatory patients in the Asthma & COPD clinic at the University Medical Center, Ho Chi Minh City from March 2016 to March 2017. Using measurement of FeNO, the ACT questionnaire and a spirometry test, correlations were determined between FeNO and the ACT score and spirometry parameters. Results: Four hundred and ten asthmatic patients (mean age 42 years; 65% female) were included and analyzed; their mean time since onset of asthma was 9.5 years. All patients were treated following step 2 to 4 of GINA guidelines. Mean (SD) FeNO was 29.5 (24.4) parts per billion (ppb) and mean (SD) ACT score was 20.5 (40). A significant difference in FeNO values was found among the three groups with different asthma control levels categorized according to the ACT score (P=0.001) but was not found among the three groups with different asthma treatment levels (P=0.425). FeNO was significantly inversely correlated with the ACT score (Spearman's r =−0.224, P<0.001) and with spirometry parameters indicate airway obstruction such as predicted FEV1, FEV1/FVC, predicted PEF and predicted FEF25-75% with Spearman's r were −0.187; −0.143; −0.091 and −0.195, respectively (all P<0.05), whereas no correlation between FeNO and FVC-an indicator of airway restriction-was found.Conclusions: In these asthmatic patients in Vietnam, an inverse correlation was found between FeNO and the ACT score and between FeNO and spirometry indicators of airway obstruction. Therefore, FeNO may be a useful tool in asthma management.

Assessment of Fraction of Exhaled Nitric Oxide and Soluble Receptor for Advanced Glycation End Products Biomarkers for Jordanian Asthmatic Children

“… 41 Moreover, significant differences in FeNO were seen between different asthma control groups. 41 Additionally, other studies indicated that FeNO values were related to several markers of asthma control, such as nighttime symptoms, beta-agonist use, and bronchodilator reversibility, 42 as well as to the use of oral or inhaled steroid treatment. 43 In addition, previous studies showed that FeNO was raised in asthmatic children, especially when asthma is uncontrolled and during exacerbations.…”

“… 38 Although, FeNO-guided asthma management was shown previously to have promising benefits, most clinical trials had variable effectiveness. 40 , 41 In a Meta‐analysis study, FeNO‐guided asthma management strategy was shown to partially improve the outcomes of pediatric asthma by reducing asthma exacerbations and improving the forced expiratory volume in a second (FEV1), at the expense of increased ICS dose without any beneficial effects on symptom control, quality of life. 39 In the setting of chronic inflammatory airway disease including asthma, conventional tests such as FEV1, reversibility or provocation tests are indirectly associated with airway inflammation.…”

Observational study of inhaled corticosteroid treatment for improved expiratory variability index in steroid-naïve asthmatic children

“…No significant correlations were observed between EVI and impulse oscillometry, baseline parameters or C-ACT scores. However, two other studies have found only weak correlations between asthma test scores and both fractional exhaled nitric oxide and forced expiratory volume in the first second of a spirometry test [8,9] The strength of our study was that patients were monitored for 6 months. The relatively mild patient population could also be considered a strength, because for those children the diagnosis of asthma is clinically challenging and lung function tests would be especially for this patient group.…”

“…No significant correlations were observed between EVI and impulse oscillometry, baseline parameters or C-ACT scores. However, two other studies have found only weak correlations between asthma test scores and both fractional exhaled nitric oxide and forced expiratory volume in the first second of a spirometry test [ 8 , 9 ].…”

Association between Childhood Asthma Control Test scores and lung pathophysiologic indicators in longitudinal measurements

“…A systemic review of 58 studies revealed a weak association between FeNO levels and asthma control in adults and children ( 28 ). Nevertheless, Nguyen et al reported associations between FeNO and Asthma Control Test (ACT) score in 410 adults ( 29 ). Stern et al observed associations of FeNO with symptom scores in 151 atopic asthmatic children during 192 days when the use of inhaled corticosteroids (ICS) was adjusted every 3 weeks according to FeNO value ( 30 ).…”