Yamakawa Michiyo, Yorifuji Takashi, Kato Tsuguhiko, Inoue Sachiko, Tokinobu Akiko, Tsuda Toshihide, Doi Hiroyuki
Center for Regional Research, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama, 700-8530, Japan,
Matern Child Health J. 2015 Sep;19(9):1956-65. doi: 10.1007/s10995-015-1703-4.
Whether or not the protective effects of breastfeeding last during or after a shift to a weaning diet is not clear. In the present study, we examined the effects of breastfeeding on hospitalization for respiratory tract infections and diarrhea in early childhood in Japan. Data were extracted from a nationwide longitudinal survey of Japanese children. We restricted the study participants to singleton children who were born after 37 gestational weeks and whose information on feeding practice during infancy were included (n = 43,367). We used logistic regression models to evaluate the associations of breastfeeding with hospitalization for the two diseases among young children (i.e., between ages 6 and 18 months, between ages 18 and 30 months, and between ages 30 and 42 months, respectively), adjusting for children's factors (sex, birth weight, childcare attendance and presence of siblings) and maternal factors (educational attainment and smoking status). Breastfeeding compared with infant formula was not associated with reduced risk of hospitalization for diarrhea during the periods we examined. Although breastfeeding was not associated with reduced risk of hospitalization for respiratory tract infections between ages 6 and 18 months, breastfeeding showed protective effects after that period: the adjusted odds ratios (95% confidence intervals) of exclusive breastfeeding were 0.82 (0.66-1.01) between ages 18 and 30 months and 0.76 (0.58-0.99) between ages 30 and 42 months. Breastfeeding may have long-term protective effects on hospitalization for respiratory tract infections after infancy, but not for diarrhea.
母乳喂养的保护作用在过渡到断奶饮食期间或之后是否持续尚不清楚。在本研究中，我们调查了母乳喂养对日本幼儿呼吸道感染和腹泻住院率的影响。数据来自一项针对日本儿童的全国性纵向调查。我们将研究参与者限制为孕龄37周后出生且包含婴儿期喂养方式信息的单胎儿童（n = 43,367）。我们使用逻辑回归模型评估母乳喂养与幼儿期（即分别为6至18个月、18至30个月和30至42个月）这两种疾病住院率之间的关联，并对儿童因素（性别、出生体重、入托情况和兄弟姐妹情况）和母亲因素（教育程度和吸烟状况）进行了调整。在我们研究的时间段内，与婴儿配方奶粉相比，母乳喂养与腹泻住院风险降低无关。虽然母乳喂养与6至18个月之间呼吸道感染住院风险降低无关，但在此之后母乳喂养显示出保护作用：18至30个月之间纯母乳喂养的调整优势比（95%置信区间）为0.82（0.66 - 1.01），30至42个月之间为0.76（0.58 - 0.99）。母乳喂养可能对婴儿期后呼吸道感染住院有长期保护作用，但对腹泻没有。
