Breast-feeding and hospitalization for asthma in early childhood: a nationwide longitudinal survey in Japan.
OBJECTIVE
Whether or not breast-feeding is protective against asthma among children is still controversial. Therefore, we examined the effects of breast-feeding on hospitalization for asthma in early childhood.


METHODS
Secondary data analyses of a nationwide longitudinal survey of children in Japan ongoing since 2001, with results collected from 2001 to 2004. We used logistic regression models to evaluate the associations of breast-feeding with hospitalization for asthma in children between the ages of 6 and 42 months, adjusting for children's factors (sex, day-care attendance and presence of older siblings) and maternal factors (educational attainment and smoking habit). Setting All over Japan.


METHODS
Term singleton children with information on feeding practices during infancy (n 43367).


RESULTS
After adjusting for maternal factors and children's factors, exclusive breast-feeding at 6-7 months of age was associated with decreased risk of hospitalization for asthma in children. The adjusted odds ratio was 0.77 (95% CI 0.56, 1.06). One-month longer duration of breast-feeding was associated with a 4% decreased risk of hospitalization for asthma (OR = 0.96; 95% CI 0.92, 0.99).


CONCLUSIONS
The protective effects of breast-feeding on hospitalization for asthma were observed in children between the ages of 6 and 42 months.
1Center for Regional Research,Okayama University,3-1-1 Tsushima-naka,Kita-ku,Okayama 700-8530,Japan.
Michiyo
M
Yamakawa
2Department of Human Ecology,Okayama University Graduate School of Environmental and Life Science,Okayama,Japan.
Takashi
T
Yorifuji
3Department of Public Health and Public Policy,Hiroshima University,Institute of Biomedical and Health Sciences,Hiroshima,Japan.
Tsuguhiko
T
Kato
4Department of Nursing,School of Health Science and Social Welfare,Kibi International University,Okayama,Japan.
Yoshitada
Y
Yamauchi
5Department of Epidemiology,Okayama University Graduate School of Medicine,Dentistry and Pharmaceutical Sciences,Okayama,Japan.
Hiroyuki
H
Doi
D001249:Asthma / Q000517:prevention & control* / Q000628:therapy; D001942:Breast Feeding; D002675:Child, Preschool; D004032:Diet; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007564:Japan; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008895:Milk, Human; D016017:Odds Ratio; D012306:Risk; D012307:Risk Factors
Asthma; Breast-feeding; Child