title: Concordance between bronchial hyperresponsiveness, fractional exhaled nitric oxide, and asthma control in children.
abstract: Previous studies on association between level of asthma control, markers of airway inflammation and the degree of bronchial hyperresponsiveness (BHR) have yielded conflicting results. Our aim was to determine the presence and severity of BHR and the concordance between BHR, asthma control, and fractional exhaled nitric oxide (FeNO) in children with asthma on therapy.
  
  
  
  In this cross-sectional observational study, children (aged 6-18 years) with asthma on British Thoracic Society (BTS) treatment steps 2 or 3, underwent comprehensive assessment of their asthma control (clinical assessment, spirometry, asthma control test [ACT], Pediatric Asthma Quality of Life Questionnaire [PAQLQ]), measurement of FeNO and BHR (using mannitol dry powder bronchial challenge test [MCT], Aridol™, Pharmaxis, Australia).
  
  
  
  Fifty-seven children (63% male) were studied. Twenty-seven children were on BTS treatment step 2 and 30 were on step 3. Overall, 25 out of 57 (43.8%) children had positive MCT. Of note, 9 out of 27 (33.3%) children with clinically controlled asthma had positive MCT. Analyses of pair-wise agreement between MCT (positive or negative), FeNO (>25 or ≤25 ppb) and clinical assessment of asthma control (controlled or partially controlled/uncontrolled) showed poor agreement between these measures.
  
  
  
  A substantial proportion of children with asthma have persistent BHR despite good clinical control. The concordance between clinical assessment of asthma control, BHR and FeNO was observed to be poor. Our findings raise concerns in the context of emerging evidence for the role of bronchoconstriction in inducing epithelial stress that may drive airway remodeling in asthma. Pediatr Pulmonol. 2016;51:1004-1009. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Pediatric Respiratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore. biju.thomas@kkh.com.sg, drbiju@doctors.net.uk.|Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore. biju.thomas@kkh.com.sg, drbiju@doctors.net.uk.
authors.forename: Biju
authors.initials: B
authors.lastname: Thomas
authors.affiliation: Department of Pediatric Respiratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore.|Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
authors.forename: Oh Moh
authors.initials: OM
authors.lastname: Chay
authors.affiliation: Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
authors.forename: John C
authors.initials: JC
authors.lastname: Allen
authors.affiliation: Department of Pediatric Respiratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore.
authors.forename: Andrea Shu Xian
authors.initials: AS
authors.lastname: Chiang
authors.affiliation: Department of Pediatric Respiratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore.|Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
authors.forename: Arun
authors.initials: A
authors.lastname: Pugalenthi
authors.affiliation: Department of Pediatric Respiratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore.|Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
authors.forename: Anne
authors.initials: A
authors.lastname: Goh
authors.affiliation: Department of Pediatric Respiratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore.
authors.forename: Petrina
authors.initials: P
authors.lastname: Wong
authors.affiliation: Department of Pediatric Respiratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore.
authors.forename: Ai Huay
authors.initials: AH
authors.lastname: Teo
authors.affiliation: Department of Pediatric Respiratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore.
authors.forename: Soh Gin
authors.initials: SG
authors.lastname: Tan
authors.affiliation: Department of Pediatric Respiratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore.|Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
authors.forename: Oon Hoe
authors.initials: OH
authors.lastname: Teoh
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D001315:Australia; D001944:Breath Tests; D016535:Bronchial Hyperreactivity / Q000188:drug therapy* / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000502:physiology; D002648:Child; D003430:Cross-Sectional Studies; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D011788:Quality of Life; D013147:Spirometry
chemical_list: D009569:Nitric Oxide
keywords: airway hyperresponsiveness; asthma; asthma control; bronchial hyperresponsiveness; fractional exhaled nitric oxide (FeNO)