TY - JOUR T1 - Bronchial hyperresponsiveness (BHR) to isocapnic hyperventilation of dry air (IHDA) in smokers is associated to airflow obstruction, chronic cough and beta-2-agonist treatment JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p4232 AU - Peter Blomstrand AU - Susanne Ekedahl AU - Birgitta Schmekel Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p4232.abstract N2 - Background: BHR to direct stimuli (i.e. metacholine) may be associated to an increased risk for progressive airflow obstruction in smokers. The clinical relevance of BHR to indirect stimuli (i.e. IHDA) is not known.Aim: To examine any association between BHR to IHDA and symptoms or spirometry in tobacco smokers.Methods: Regular tobacco smokers (>25 smoke years) attending Primary Health Care Centres were invited to participate. Subjects with therapy requiring severe diseases (except for COPD) were excluded. A questionnaire regarding medication, smoking habits and symptoms was completed by 128 smokers. Spirometry (FEV1 and VC) and impulse oscillometry (resonant frequency = Fres) were recorded at baseline (MS-IOS Digital Instrument, Erich Jaeger AG, Germany). A four minute IHDA was followed by measurements of Fres during six minutes. An increase in Fres of >2.4 Hz was defined as the cut off limit of BHR.Results: 85 of 128 smokers exhibited BHR and demography or tobacco smoke exposure did not differ between the two subgroups. Smokers with BHR had worse spirometry at rest (p<0.05) and a history of chronic cough (p<0.01). Fifteen smokers regularly inhaled a β2 agonist and they all exhibited BHR, had higher bronchial tonus at rest (p<0.05) and exhibited greater response to IHDA than non-treated smokers with BHR (p<0.05).Conclusions: BHR to IHDA is common among smokers and associated to chronic cough and airflow obstruction. BHR is even more common among smokers using β2 agonists. It is not known whether this is a cause or an effect of a 12 hour interruption of β2 agonist treatment prior to challenge. ER -