Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA.
Center for Human Growth and Development, University of Michigan, Ann Arbor, MI 48109, USA.
Nutrients. 2020 Jan 30;12(2):358. doi: 10.3390/nu12020358.
In breastfed infants, human milk provides the primary source of iodine to meet demands during this vulnerable period of growth and development. Iodine is a key micronutrient that plays an essential role in hormone synthesis. Despite the importance of iodine, there is limited understanding of the maternal factors that influence milk iodine content and how milk iodine intake during infancy is related to postnatal growth. We examined breast milk samples from near 2 weeks and 2 months post-partum in a mother-infant dyad cohort of mothers with pre-pregnancy weight status defined by body mass index (BMI). Normal (NW, BMI < 25.0 kg/m) is compared to overweight/obesity (OW/OB, BMI ≥ 25.0 kg/m). The milk iodine concentration was determined by inductively coupled plasma mass spectrometry. We evaluated the associations between iodine content at 2 weeks and infant anthropometrics over the first year of life using multivariable linear mixed modeling. Iodine concentrations generally decreased from 2 weeks to 2 months. We observed no significant difference in iodine based on maternal weight. A higher iodine concentration at 2 weeks was associated with a larger increase in infant weight-for-age and weight-for-length Z-score change per month from 2 weeks to 1 year. This pilot study shows that early iodine intake may influence infant growth trajectory independent of maternal pre-pregnancy weight status.
在母乳喂养的婴儿中，母乳是满足生长发育关键期碘需求的主要来源。碘是一种关键的微量营养素，对激素合成起着至关重要的作用。尽管碘很重要，但人们对影响母乳碘含量的母体因素以及婴儿期母乳碘摄入量与产后生长的关系了解有限。我们在一个母亲-婴儿对子队列中检查了近 2 周和 2 个月产后的母乳样本，该队列的母亲在妊娠前根据体重指数（BMI）定义了体重状况。将正常体重（NW，BMI<25.0kg/m）与超重/肥胖（OW/OB，BMI≥25.0kg/m）进行了比较。采用电感耦合等离子体质谱法测定母乳碘浓度。我们使用多变量线性混合模型评估了 2 周时碘含量与婴儿在生命第一年的人体测量指标之间的关联。碘浓度通常从 2 周下降到 2 个月。我们没有观察到母体体重对碘含量的显著影响。2 周时的碘浓度较高与 2 周至 1 年期间婴儿体重-年龄和体重-长度 Z 分数每月的增长幅度更大有关。这项初步研究表明，早期碘摄入量可能会影响婴儿的生长轨迹，而与母亲妊娠前的体重状况无关。
