Relationship between bronchial hyperresponsiveness and lung function in children age 5 and 6 with and without asthma.
OBJECTIVE
It is unknown whether wheezy children have bronchial hyperresponsiveness (BHR) or which lung function parameters are correlated with BHR in children. We evaluated the relationship between BHR parameters and the lung functions by minimizing the effects of age and height in asthmatic, non-asthmatic wheezers and healthy children.


METHODS
The subjects comprised of 154 children aged 5 and 6 years (78 males, 76 females), who were divided into three groups: asthmatics, non-asthmatic wheezers and healthy controls. Spirometry and a methacholine inhalation challenge by the oscillation method were performed.


RESULTS
The age of the study cohort was 5.9 ± 0.2 years (mean ± standard deviation), and the height was 114.4 ± 5.3 cm. No significant differences in height, weight, body mass index or lung function were observed in the three groups. The minimal dose of methacholine to start bronchoconstriction, a parameter of bronchial sensitivity, was lower in asthmatics and non-asthmatic wheezers than that in controls. The speed of bronchoconstriction in response to methacholine, a parameter of bronchial reactivity, was strongly correlated with baseline respiratory resistance (Rrs cont) in all three groups.


CONCLUSIONS
Our data suggest that it not possible to distinguish preschool children with asthma from non-asthmatic wheezers based on their bronchial sensitivity and that the baseline Rrs has a strong effect on the bronchial reactivity in children.
Department of Pediatrics, Gunma University Graduate School of Medicine, Gunma, Japan. satorutkm@true.ocn.ne.jp
Satoru
S
Takami
Hiroyuki
H
Mochizuki
Reiko
R
Muramatsu
Satomi
S
Hagiwara
Hirokazu
H
Arakawa
D000367:Age Factors; D001249:Asthma / Q000503:physiopathology*; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D016535:Bronchial Hyperreactivity / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D012129:Respiratory Function Tests; D012135:Respiratory Sounds / Q000503:physiopathology*