METHODS: WIC administrative data, collected from 2013-2020 on issued amount (categorical: fully formula fed, mostly formula fed, mostly breastfed, fully breastfed) and type of infant formula (standard cow\'s milk formula, and three specialty formulas: any CSSF, any soy-based formula, and any cow\'s milk-based formula with added rice starch) and obesity at ages 2-4 years (defined as a Body Mass Index z-score ≥ 95th percentile according to World Health Organization growth standard) were used to construct a cohort (n = 59,132). Associations of infant formula exposures and race/ethnicity with obesity risk were assessed in Poisson regression models, and modification of infant feeding associations with obesity by neighborhood context was assessed with interaction terms.
RESULTS: Any infant formula exposure was associated with significantly higher obesity risk relative to fully breastfeeding. Receipt of a CSSF was associated with 5% higher obesity risk relative to the standard and other specialty infant formulas (risk ratio 1.05, 95% confidence interval 1.02, 1.08) independent of breastfeeding duration and receipt of other specialty infant formulas. The association between CSSF and obesity risk was stronger in neighborhoods with healthier food environments (10% higher risk) compared to less healthy food environments (null). Racial/ethnic disparities in obesity risk were robust to adjustment for infant formula exposure and neighborhood environment.
CONCLUSIONS: Among specialty infant formulas issued by WIC, only CSSFs were associated with elevated obesity risk, and this association was stronger in healthier food environments. Future research is needed to isolate the mechanism underlying this association.
方法:WIC管理数据,从2013-2020年收集的已发行金额(分类:完全配方喂养,主要是配方喂养,主要是母乳喂养,完全母乳喂养)和婴儿配方食品的类型(标准牛奶配方食品,和三个特殊配方:任何CSSF,任何大豆配方,和任何添加了大米淀粉的牛奶配方奶粉)和2-4岁的肥胖(根据世界卫生组织的生长标准定义为体重指数z评分≥95百分位数)用于构建队列(n=59,132)。在泊松回归模型中评估了婴儿配方奶粉暴露和种族/民族与肥胖风险的关联。通过交互项评估了根据社区背景对婴儿喂养与肥胖关联的修改。
结果:与完全母乳喂养相比,任何婴儿配方奶粉暴露与肥胖风险显著升高相关。与标准和其他专业婴儿配方食品相比,接受CSSF与肥胖风险高5%(风险比1.05,95%置信区间1.02,1.08)相关,与母乳喂养持续时间和接受其他专业婴儿配方食品无关。与较不健康的食物环境(无效)相比,在食物环境更健康的社区(风险高10%)中,CSSF与肥胖风险之间的关联更强。肥胖风险的种族/种族差异对于婴儿配方奶粉暴露和邻里环境的调整是强大的。
结论:在WIC发行的特殊婴儿配方奶粉中,只有CSSF与肥胖风险升高相关,在更健康的食物环境中,这种关联更强。需要进一步的研究来分离这种关联的潜在机制。