Longitudinal changes of pulmonary function and bronchial responsiveness in cough-variant asthma treated with bronchodilators alone.
Cough due to cough-variant asthma (CVA) responds well to bronchodilators such as beta 2 adrenergic agonists. The aim of this study was to assess longitudinal changes of pulmonary function and bronchial responsiveness in CVA, which was treated with bronchodilators alone. Seventeen CVA patients recorded intensity and frequency of cough every day. Spirometry and provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 second (PC20) were measured in the run-in period and after cough almost completely relieved on therapy. Cough score had improved within 2 weeks after the initiation of bronchodilator therapy. Forced expiratory volume in one second (FEV1) was significantly increased from 2.7 +/-0.7 L in the run-in period to 2.8+/-0.7 L after improvement of cough. However, the geometric mean (GSEM) PC20 value did not change from the run-in period [1542 (GSEM 1.29) microg/mL] to the time of improvement [2600 (GSEM 1.43) microg/mL]. Mildly increased bronchial responsiveness in CVA does not improve when only bronchodilator therapy is carried out. Because bronchial hyperresponsiveness has been shown to be a risk factor for typical asthma onset from CVA, the effect of inhaled corticosteroids on the longitudinal changes in bronchial responsiveness should be examined.
Nobata
Kouichi
K
Department of Internal Medicine, Kurobe City Hospital, Kurobe, Japan. k-nobata@yg7.so-net.ne.jp
Fujimura
Masaki
M
Tsuji
Hiroshi
H
Ishiura
Yoshihisa
Y
Myou
Shigeharu
S
Nakao
Shinji
S
Takazakura
Eisuke
E
D001249:Asthma / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D001980:Bronchi / Q000187:drug effects* / Q000502:physiology; D016535:Bronchial Hyperreactivity / Q000188:drug therapy; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D003371:Cough / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
D001993:Bronchodilator Agents