TY - JOUR
T1 - Comparison of percentage fall in FVC at the provocative concentration of methacholine causing a 20% fall in FEV1 between patients with asymptomatic bronchial hyperresponsiveness and mild asthma
AU - Yoo, Young
AU - Ji, Tae Choung
AU - Yu, Jinho
AU - Do, Kyun Kim
AU - Sun, Hee Choi
AU - Young, Yull Koh
N1 - Funding Information:
This study was supported in part by BK 21 Project for Medicine, Dentistry, and Pharmacy, Seoul National University.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2007/7
Y1 - 2007/7
N2 - Background: A significant proportion of individuals who have no symptoms of asthma or other respiratory diseases show bronchial hyperresponsiveness (BHR). BHR is usually assessed by measuring the provocative concentration of methacholine causing a 20% fall in FEV1 (PC20). The percentage fall in FVC at the PC20 (ΔFVC) has been suggested to reflect maximal airway response and to be a more useful index of disease severity in asthma than PC20. The aim of this study was to investigate whether asymptomatic BHR would differ from symptomatic BHR with regard to ΔFVC. Methods: Methacholine bronchial challenge tests were conducted in children with no past or current symptoms of asthma, allergic rhinitis, or other respiratory diseases, who were identified among siblings of children with asthma. Forty-three children with asymptomatic BHR (PC 20 < 16 mg/mL) were recruited, and 43 children with mild asthma who were matched for age, sex, and PC20 were selected (mild asthma group). The ΔFVC on methacholine concentration-response curves was retrospectively analyzed in the two groups. Results: There were no differences in the frequency of atopy, blood eosinophil counts, serum IgE levels, and spirometric values between the asymptomatic BHR and mild asthma groups. Mean (± SD) ΔFVC was significantly (p = 0.005) lower in the asymptomatic BHR group (14.5 ± 3.6%) than in the mild asthma group (16.9 ± 4.3%). Conclusions: Our results suggest that children with asymptomatic BHR have a lower level of maximal airway response than mild asthmatics with a similar degree of BHR. This may be a possible explanation for the lack of symptoms in subjects with asymptomatic BHR.
AB - Background: A significant proportion of individuals who have no symptoms of asthma or other respiratory diseases show bronchial hyperresponsiveness (BHR). BHR is usually assessed by measuring the provocative concentration of methacholine causing a 20% fall in FEV1 (PC20). The percentage fall in FVC at the PC20 (ΔFVC) has been suggested to reflect maximal airway response and to be a more useful index of disease severity in asthma than PC20. The aim of this study was to investigate whether asymptomatic BHR would differ from symptomatic BHR with regard to ΔFVC. Methods: Methacholine bronchial challenge tests were conducted in children with no past or current symptoms of asthma, allergic rhinitis, or other respiratory diseases, who were identified among siblings of children with asthma. Forty-three children with asymptomatic BHR (PC 20 < 16 mg/mL) were recruited, and 43 children with mild asthma who were matched for age, sex, and PC20 were selected (mild asthma group). The ΔFVC on methacholine concentration-response curves was retrospectively analyzed in the two groups. Results: There were no differences in the frequency of atopy, blood eosinophil counts, serum IgE levels, and spirometric values between the asymptomatic BHR and mild asthma groups. Mean (± SD) ΔFVC was significantly (p = 0.005) lower in the asymptomatic BHR group (14.5 ± 3.6%) than in the mild asthma group (16.9 ± 4.3%). Conclusions: Our results suggest that children with asymptomatic BHR have a lower level of maximal airway response than mild asthmatics with a similar degree of BHR. This may be a possible explanation for the lack of symptoms in subjects with asymptomatic BHR.
KW - Asymptomatic bronchial hyperresponsiveness
KW - Maximal airway response
KW - Percentage fall in FVC at the provocative concentration of methacholine causing a 20% fall in FEV
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U2 - 10.1378/chest.06-2943
DO - 10.1378/chest.06-2943
M3 - Article
C2 - 17505037
AN - SCOPUS:34447505155
VL - 132
SP - 106
EP - 111
JO - Chest
JF - Chest
SN - 0012-3692
IS - 1
ER -