Infant Growth, Milk Composition, and Maternal Energetics in a High Altitude Environment

高海拔环境中的婴儿生长、乳汁成分和母体能量

• 批准号: 1518013
• 负责人: Elizabeth Quinn
• 金额: $ 35.5万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1518013&HistoricalAwards=false
• 关键词: Infant; Growth; Milk; Composition; Maternal

For the vast majority of human history, breast milk has been the primary source of nutrients during infancy. Recent research has shown human milk to be a tremendously complex fluid containing a wealth of macronutrients, immune factors and hormonal components, all of which get fed to the baby. Similarly, mothers' milk is incredibly variable, with women in different societies and living situations producing different amounts of many of these components. Despite a growing body of research, there is still much left to understand about how and why milk varies in different ecological circumstances and how these differences may affect the health and growth of infants. This study takes a detailed look at a population which lives in the high altitude environment of the Nubri Valley, Nepal, to investigate how breast milk may be involved in the regulation of infant growth under considerable ecological stress. The project will provide opportunities for undergraduate and graduate student research and training, and facilitate regional health and science education at the study location. Understanding how ecological pressures such as altitude and cold stress influence human milk composition and in turn, infant metabolism and physiological development, may be crucial in understanding the risk factors for overweight and metabolic dysfunction in industrialized and rapidly industrializing populations.It is likely that there has been considerable natural selection on human milk composition given the primary role human milk has during infancy, itself a critical period of selection. Growth factors and metabolic hormones found in milk show significant associations with linear growth, weight gain, fat free mass, and size for age, making milk born hormones and cytokines likely candidates for developmental programming of infant body composition. However, these associations have never been investigated in an ecologically stressed population where environmental selection on infant phenotypes may be severe. This project will investigate associations between ecology, maternal physiology, milk composition, and infant growth and development in 115 mother-infant pairs from nine villages in the Nubri Valley of the Himalayas (Nepal). The population is ethnically Tibetan, with family histories recording occupation in the valley for at least 700 hundreds following immigration from the Tibetan plateau. Villages range in altitude from 7,500-13,100 feet above sea level. Milk samples, metabolic tests, and thermal body scans will be collected at four time points over the first year of infant life. The thermal imaging of mother and child is an innovation which will show differences in body fat patterning. Additionally, interviews of the mothers and anthropometric measurements (height, weight, body composition) of both mother and child will be collected beginning at birth and at two month intervals afterward. The resulting data will provide the most complete picture ever collected of altitude- and seasonality-associated differences in growth, milk hormones, and maternal reproductive condition across the first year of life.

在人类的绝大多数历史中，母乳一直是婴儿期营养的主要来源。最近的研究表明，母乳是一种极其复杂的液体，含有丰富的常量营养素、免疫因子和激素成分，所有这些都可以喂给婴儿。同样，母乳的变化也非常大，不同社会和生活环境的女性产生的这些成分的数量也不同。尽管研究不断增多，但关于牛奶在不同生态环境下如何以及为何会发生变化，以及这些差异如何影响婴儿的健康和成长，仍有很多问题需要了解。这项研究详细观察了生活在尼泊尔努布里山谷高海拔环境中的人群，以调查在相当大的生态压力下母乳如何参与婴儿生长的调节。该项目将为本科生和研究生的研究和培训提供机会，并促进研究地点的区域健康和科学教育。了解海拔和寒冷应激等生态压力如何影响母乳成分，进而影响婴儿的新陈代谢和生理发育，对于了解工业化和快速工业化人群超重和代谢功能障碍的危险因素可能至关重要。考虑到母乳在婴儿期（本身就是选择的关键时期）的主要作用，母乳成分可能发生了相当大的自然选择。牛奶中发现的生长因子和代谢激素与线性生长、体重增加、去脂质量和年龄大小具有显着相关性，使得牛奶产生的激素和细胞因子可能成为婴儿身体成分发育规划的候选者。然而，这些关联从未在生态紧张的人群中进行过研究，因为环境选择对婴儿表型的影响可能很严重。该项目将调查来自喜马拉雅山努布里山谷（尼泊尔）9 个村庄的 115 对母婴的生态、孕产妇生理、乳汁成分和婴儿生长发育之间的关联。这里的人口是藏族，根据家族史记载，至少有 700 万人从青藏高原移民到这里居住。村庄的海拔高度为 7,500-13,100 英尺。将在婴儿出生后第一年的四个时间点收集牛奶样本、代谢测试和热身体扫描。母亲和孩子的热成像是一项创新，它将显示身体脂肪图案的差异。此外，将从出生时开始以及出生后每隔两个月收集母亲的访谈以及母亲和孩子的人体测量数据（身高、体重、身体成分）。 由此产生的数据将提供迄今为止收集到的关于出生第一年中与海拔和季节性相关的生长、乳汁激素和孕产妇生殖状况差异的最完整图片。