Preterm human milk composition in conditions of maternal overweight and obesity and effects of milk constituents on preterm infant body composition

考虑到孕期和哺乳期母亲超重和肥胖（OW/OB）的发生率不断上升，关于母体代谢通过改变早产儿母乳成分对早产儿健康的影响存在知识空白。迫切需要确定由产妇OW/OB引起的早产儿乳成分的纵向变化，特别是与早产儿健康结果相结合的变化。我们的长期目标是优化早产儿条件下母乳营养质量的知识，同时考虑到妊娠和哺乳期间孕产妇健康的流行病学变化。总体目标是记录早产儿母乳成分的纵向变化，特别是母乳脂肪酸（FA）和激素，与母亲OW/OB相关，并测量母乳成分对婴儿身体成分的调节作用。我们的中心假设是，OW/OB女性产生的早产儿乳汁成分与正常体重女性不同，早产儿肥胖易受母体代谢状态和饮食改变导致的乳汁成分的影响。这项拟议研究的基本原理是推进和量身定制早产儿营养建议，确保指导方针考虑到婴儿和母亲的新陈代谢。为了实现这些目标并检验假设，目的1将记录与婴儿身体成分调节相关的早产儿乳FA和激素的纵向变化，测量母亲OW/OB导致的变异性。这将在一项针对母亲和早产儿的前瞻性队列研究中完成，该研究纳入两组（n=144名参与者）：1。主要：妊娠280/7-316/7周分娩的妇女及其婴儿（n=42名妇女，n=42名婴儿）和2。参考：比较妊娠340/7-366/7周分娩的妇女及其婴儿（n=30名妇女，n=30名婴儿）。筛查和登记将对孕前体重指数（BMI）进行计数，以便在两组正常、超重和肥胖的BMI（各占三分之一）之间形成均匀分布。在哺乳的第5周，将获得一系列的早产儿乳汁样本。严格的临床表型妇女和婴儿将发生，以及获得妇女的饮食摄入量在哺乳期。目的2将评估牛奶FA和激素摄入量与早产儿身体组成的关系。空气置换容积描记仪以及皮肤褶皱厚度将测量婴儿的身体成分。将通过记录每日营养摄入量来估计婴儿牛奶FA和激素的摄入量，然后评估与婴儿身体成分的关系。拟议的贡献是重要的，因为它们将确定产妇和早产儿营养的各个方面，这些方面可以进行干预，并且最有可能解决母乳的可变性和早产儿的代谢易感性，这些问题尚未纳入婴儿喂养标准。计划中的研究具有创新意义，它建议利用加强的风险分层，在一定程度上根据怀孕和哺乳期间的产妇代谢和健康指标，推动科学确定早产儿的营养状况和需求。

Considering the increasing rates of maternal overweight and obesity (OW/OB) in pregnancy and lactation, a knowledge gap exists regarding influences of the maternal metabolism on preterm infant health through alterations in preterm human milk composition. There is a critical need to define longitudinal changes in preterm milk composition resulting from maternal OW/OB especially in conjunction with preterm infant health outcomes. Our long-term goal is to optimize knowledge of human milk nutrient quality in conditions of preterm birth while ac- counting for the changing epidemiology of maternal health in pregnancy and lactation. The overall objective is to document longitudinal changes in preterm human milk composition, specifically milk fatty acids (FA) and hormones, associated with maternal OW/OB and measure regulatory effects of milk components on infant body composition. Our central hypothesis is that women with OW/OB produce preterm milk that is compositionally different from women with normal weight and that preterm infant adiposity is susceptible to maternal metabolic status and diet via altered milk composition. The rationale for this proposed research is to advance and tailor recommendations for preterm infant nutrition, assuring guidelines account for infant and maternal metabolism. To fulfill these objectives and test the hypotheses, Aim 1 will document longitudinal changes in preterm milk FA and hormones associated with regulation of infant body composition, measuring variability resulting from maternal OW/OB. This will be accomplished in a prospective cohort study of mother-preterm infant dyads with two groups enrolled (n=144 total participants): 1. Primary: women who deliver at 280/7-316/7 weeks of gestation and their infants (n=42 women, n=42 infants) and 2. Reference: comparison women who deliver at 340/7-366/7 weeks of gestation and their infants (n=30 women, n=30 infants). Screening and enrollment will ac- count for pre-pregnancy body mass index (BMI) to accrue an even distribution across normal, overweight and obese BMIs (one-third in each) for both groups. Serial preterm milk samples will be obtained through week 5 of lactation. Rigorous clinical phenotyping of women and infants will occur as well as obtaining women’s dietary intake during lactation. Aim 2 will assess the association of milk FA and hormone intake with preterm infant body composition. Air displacement plethysmography as well as skin folds thickness will measure infant body composition. Infant intake of milk FA and hormones will be estimated by documenting daily nutritional intake and then evaluated in relation to infant body composition. The proposed contributions are significant because they will identify aspects of both maternal and preterm infant nutrition that are amenable to intervention and which hold greatest potential to address human milk variability and the metabolic susceptibilities of the preterm infant not as yet incorporated within infant feeding standards. The planned research is innovative in proposing to advance the science towards defining preterm infant nutritional status and requirements using enhanced risk stratification, based in part on indicators of maternal metabolism and health during pregnancy and lactation.