RT Journal Article
SR Electronic
T1 Relationships of BHR to methacholine/AMP to bronchodilator response in asthmatic children
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP erj00496-2010
DO 10.1183/09031936.00049610
A1 K. Lee
A1 C.K. Kim
A1 Y.Y. Koh
YR 2010
UL http://erj.ersjournals.com/content/early/2010/08/20/09031936.00049610.abstract
AB Bronchodilator response (BDR) is assessed to estimate the reversibility of airflow obstruction. Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma and is usually measured by bronchial challenges using direct or indirect stimuli. The aim of this study was to compare BHR to methacholine (direct) and that to adenosine 5′-monophosphate (AMP) (indirect) with regard to their relationships to BDR in asthmatic children.Methacholine and AMP challenge tests were performed on 138 children with mild to moderate asthma, and a provocative concentration causing a 20% decline in FEV1 (PC20) was determined for each challenge. BDR was calculated as the change in FEV1, expressed as % of the initial value, after inhalation of 400 μg salbutamol.Methacholine PC20 correlated significantly but weakly with BDR (r= −0.254, P=0.003). However, there was a significant and strong correlation between AMP PC20 and BDR (r= −0.489, P=0.000). For AMP PC20, the relationship was closer than for methacholine PC20 (comparison between correlation coefficients: P=0.024). The same figures were observed, when BDR was expressed as % of the predicted value.A stronger correlation of BDR with AMP PC20 than with methacholine PC20 suggests that BDR may be reflected better by BHR as assessed by AMP challenge than by methacholine challenge.