中国母乳喂养与儿童体质指数、超重及肥胖关系

目的 使用中国家庭追踪调查数据探究中国母乳喂养与儿童体质指数（BMI）、超重及肥胖关系，判定母乳喂养能否预防儿童肥胖，为制订儿童肥胖防治策略提供科学依据。方法 收集2 388名>5岁儿童的相关资料，对母乳喂养的持续时间二分为有与没有、≥6个月与<6个月、≥8个月与<8个月和≥12个月与<12个月；对每一种二分法采用logistic回归分析计算倾向评分，比较BMI与母乳喂养状况差异是否有统计学意义，在较高BMI百分位的儿童中结合分位数回归进行判断。结果 在调整倾向得分后，并未发现母乳喂养对减少体重有任何显著的影响，相反，长时间的母乳喂养可以增加肥胖的风险（OR=1.42，95% CI=1.07~1.89，P=0.02）；分位数回归显示，母乳喂养在拥有极端BMI的儿童中未发挥有益作用。结论 母乳喂养在降低BMI或儿童超重和肥胖的风险方面未发现明显的保护作用。

Relationship of breastfeeding with childhood BMI,overweight and obesity: findings from the China family panel studies

Objective To explore the relationship of breastfeeding with childhood body mass index (BMI),overweight and obesity based on data collected by the China Family Panel Studies,and to explore whether breastfeeding can prevent childhood obesity for childhood obesity prevention.Methods Data were collected from 2 388 children aged ≥5 years.The duration of breastfeeding was first treated as a continuous variable and subsequently dichotomized into ever vs.never, ≥6 months vs.<6 months, ≥8 months vs.<8 months and ≥12 months vs.<12 months.A propensity score was calculated for various confounding factors via every dichotomization.We compared whether there is a significant difference in BMI regarding breastfeeding status.We also performed quantile regression on the upper quantiles of the BMI distribution.Results We did not find any statistically significant effect of breastfeeding on reducing body weight after adjusting for the propensity score.Instead,our result indicates that too long duration of breastfeeding can increase the risk of being overweight (odds ratio=1.42,95% confidence interval:1.07-1.89;P=0.02).Quantile regression revealed no beneficial effect of breastfeeding among children with extreme BMI.Conclusion Our research finds no significant protective effect of breastfeeding in reducing BMI or the risk of overweight and obesity among children in China.