Association of overweight with asthma symptoms in Japanese school children.
BACKGROUND
Most studies regarding the association of obesity with asthma have been performed in the Western countries. This study is a nationwide survey conducted in Japan.


METHODS
A cross-sectional and questionnaire-based survey was performed among children aged 6-7, 13-14, and 16-17 years, using the ISAAC questionnaire. Overweight was defined as BMI ≥ 90th according to the reference values for Japanese children obtained during 1978-1981.


RESULTS
Of a total of 179 218 children, 149 464 replied to the questionnaire (response rate 83.4%). After omitting incomplete data, 139 117 were analyzed. In all the age groups, being overweight was associated with current asthma after adjustment for confounding factors (adjusted OR: 1.24 in children 6-7 years of age, 1.31 in those 13-14 years, and 1.32 in those 16-17 years). These tendencies were observed in both genders. Overweight was a risk factor for nocturnal cough, independent of current asthma in the older age groups (adjusted OR: 1.21 in children 13-14 years, and 1.17 in those 16-17 years).


CONCLUSIONS
There is a clear association between obesity and current asthma in Japanese school-aged children. Mechanisms through which obesity related with nocturnal cough might be different from those of obesity-associated asthma.
Okabe
Yoshie
Y
Department of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan.
Itazawa
Toshiko
T
Adachi
Yuichi
Y
Yoshida
Koichi
K
Ohya
Yukihiro
Y
Odajima
Hiroshi
H
Akasawa
Akira
A
Miyawaki
Toshio
T
D000293:Adolescent; D000367:Age Factors; D001249:Asthma / Q000453:epidemiology*; D015992:Body Mass Index; D002648:Child; D003371:Cough / Q000453:epidemiology; D003430:Cross-Sectional Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D050177:Overweight / Q000453:epidemiology*; D015995:Prevalence