Breastfeeding duration is inversely associated with asthma in Japanese children aged 3 years.

OBJECTIVE

Recent meta-analyses found an inverse relationship between breastfeeding duration and asthma in children. The present cross-sectional study investigated the associations between breastfeeding duration and the prevalence of wheeze and asthma in Japanese children aged 3 years.

METHODS

Subjects were 6412 children who participated in the Kyushu Okinawa Child Health Study. Data were collected using a self-administered questionnaire. Wheeze was defined according to the criteria of the International Study of Asthma and Allergies in Childhood. Asthma was considered present if the child had been diagnosed by a physician as having asthma. Associations of breastfeeding duration with wheeze and asthma were estimated using multivariate generalized estimating equation methods adjusted for maternal, family, and health characteristics.

RESULTS

The prevalence values of wheeze and asthma were 19.5% and 7.0%, respectively. Compared with <4 months of exclusive breastfeeding, exclusive breastfeeding for ≥4 months was not significantly associated with wheeze or asthma. Compared with <10 months of breastfeeding duration regardless of exclusivity, 10 to <14 months, 14 to <19 months, and 19 months or more of breastfeeding duration regardless of exclusivity were independently inversely related to asthma: the adjusted odds ratios [ORs; 95% confidence intervals (CIs)] were 0.69 (0.52-0.91, p = 0.01), 0.73 (0.56-0.97, p = 0.03), and 0.67 (0.51-0.88, p = 0.004), respectively. No association was found between breastfeeding duration regardless of exclusivity and wheeze.

CONCLUSIONS

We confirmed an inverse association between breastfeeding duration regardless of exclusivity and asthma.