Inclusion and exclusion criteria.

Background Current research suggests that energy transfer through human milk influences infant nutritional development and initiates metabolic programming, influencing eating patterns into adulthood. To date, this research has predominantly been conducted among women in high income settings and/or among undernourished women. We will investigate the relationship between maternal body composition, metabolic hormones in human milk, and infant satiety to explore mechanisms of developmental satiety programming and implications for early infant growth and body composition in Samoans; a population at high risk and prevalence for overweight and obesity. Our aims are (1) to examine how maternal body composition influences metabolic hormone transfer from mother to infant through human milk, and (2) to examine the influences of maternal metabolic hormone transfer and infant feeding patterns on early infant growth and satiety. Methods We will examine temporal changes in hormone transfers to infants through human milk in a prospective longitudinal cohort of n = 80 Samoan mother-infant dyads. Data will be collected at three time points (1, 3, & 4 months postpartum). At each study visit we will collect human milk and fingerpick blood samples from breastfeeding mother-infant dyads to measure the hormones leptin, ghrelin, and adiponectin. Additionally, we will obtain body composition measurements from the dyad, observe breastfeeding behavior, conduct semi-structured interviews, and use questionnaires to document infant hunger and feeding cues and satiety responsiveness. Descriptive statistics, univariate and multivariate analyses will be conducted to address each aim. Discussion This research is designed to advance our understanding of variation in the developmental programming of satiety and implications for early infant growth and body composition. The use of a prospective longitudinal cohort alongside data collection that utilizes a mixed methods approach will allow us to capture a more accurate representation on both biological and cultural variables at play in a population at high risk of overweight and obesity.背景 现有研究表明，通过母乳进行的能量传递会影响婴儿的营养发育，并启动代谢程序化（metabolic programming）过程，进而影响个体直至成年的饮食模式。迄今为止，此类研究主要集中在高收入地区女性或营养不良女性群体中开展。本研究将探究萨摩亚人群中母亲身体成分、母乳代谢激素与婴儿饱腹感之间的关联，以阐明发育性饱腹感程序化的作用机制，以及其对婴儿早期生长与身体成分的影响——萨摩亚是超重与肥胖高发且患病率极高的人群。本研究的目标为：（1）阐明母亲身体成分如何通过母乳介导代谢激素从母体向婴儿的传递过程；（2）探究母体代谢激素传递与婴儿喂养模式对婴儿早期生长及饱腹感的影响。 方法 本研究将针对80对萨摩亚母婴对开展前瞻性纵向队列研究，以探究通过母乳向婴儿传递的激素随时间的变化规律。研究将在产后1、3及4个月三个时间点收集数据。每次研究随访时，我们将采集母乳喂养母婴对的母乳与指尖血样本，以检测瘦素（leptin）、饥饿素（ghrelin）与脂联素（adiponectin）这三种激素的水平。此外，我们还将采集母婴双方的身体成分数据、观察母乳喂养行为、开展半结构化访谈，并通过问卷记录婴儿的饥饿与喂养信号及饱腹感反应性。本研究将采用描述性统计、单变量及多变量分析方法，以达成前述两项研究目标。 讨论 本研究旨在深化我们对饱腹感发育程序化差异的理解，及其对婴儿早期生长与身体成分的潜在影响。采用前瞻性纵向队列研究结合混合方法的数据收集策略，将使我们能够更准确地捕捉超重与肥胖高风险人群中发挥作用的生物学与文化变量特征。