TY - JOUR T1 - Relationship between airway inflammation and bronchial responsiveness in children with and without asthma JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P3522 AU - Kim van de Kant AU - Kai-Häkon Carlsen AU - Petter Mowinckel AU - Karin Lødrup Carlsen Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P3522.abstract N2 - Bronchial hyperresponsiveness (BHR) is common in asthma, but can also be detected in people without asthma. Information about the association between BHR and airway inflammation in the absence of asthma is scarce. We studied airway inflammation in relation to BHR by exercise induced bronchoconstriction (EIB,n=870) and methacholine bronchial challenge (PD20; inhaled methacholine dose causing 20% FEV1 reduction,n=997) at age 10 in a population based birth cohort.Fractional exhaled nitric oxide (FeNO), serum eosinophil and neutrophil counts were assessed before challenge tests. Positive EIB was defined as FEV1 fell ≥10% after treadmill test (heart rate 90-95% of maximum). Positive PD20 was defined as ≤8 μmol methacholine. Allergic sensitisation (AS, positive skin test/specific IgE>0.35 kU/l to allergens), allergic rhinitis, asthma, age and sex were studied as potential confounders. Logistic regression was performed for positive BHR and robust regression for BHR severity.BHR assessed with PD20 was related to FeNO and eosinophils when adjusted for AS, rhinitis and asthma (OR (95%CI): 1.47 (1.08, 2.00) and 1.40 (1.09, 1.79), p<0.05). FeNO and eosinophils were also related to severity of BHR to PD20 (β:(95%CI): -2.89 (-4.53, -1.26) and -4.24 (-7.15, -1.32), p<0.05). EIB was not associated with FeNO and eosinophils after adjusting for confounders (p>0.05). Neutrophils were not related to BHR tested with PD20 and EIB.Eosinophilic inflammatory markers, not neutrophilic markers, were associated with BHR to a direct challenge test. Eosinophilic inflammation might be stronger related to BHR induced by methacholine than exercise induced BHR in a heterogeneous paediatric population. ER -