CARBOHYDRATE ENERGY ABSORPTION IN PREMATURE INFANTS

早产儿的碳水化合物能量吸收

基本信息

批准号：
3317305
负责人：
Craig Lawrence Kien
金额：
$ 28.68万
依托单位：
CHILDREN'S HOSPITAL (COLUMBUS)
依托单位国家：
美国
项目类别：
财政年份：
1988
资助国家：
美国
起止时间：
1988-02-01 至 1995-11-30
项目状态：
已结题

项目摘要

Fetal intestinal lactase activity is extremely low prior to 32 - 34 wk gestation but appears to rise rapidly thereafter. Breath H2 concentration and the rate of whole body acetate production are high in preterm infants 32-36 wk post-conceptional age suggesting that lactose is largely fermented in the colon, but studies of growth and lactose tolerance imply that lactose hydrolysis is more efficient in post-natal life than predicted from these indirect indices of fermentation activity. During the last year of the present grant, a dual stable tracer technique was used to estimate a coefficient of in vivo lactose digestion (hydrolysis) in preterm infants 33-34 wk post-conceptional age. Based on the initial values (range: 0.8 - 1.2), it is hypothesized that lactose digestion is efficient (> 0.8) in preterm infants > 32 wk post- conceptional age (Aim 3). The Principal Hypotheses of this proposal address lactose digestion in preterm infants less than 32 wk post- conceptional age: (1) The coefficient of hydrolysis of lactose is < 0.80 and is dependent on the lactose intake. (2) At the lactose intakes normally ingested by such infants, the rate of entry into the circulation of lactose-derived glucose is insufficient to suppress (via insulin secretion) hepatic glucose output. To address these hypotheses, four Primary Specific Aims (Experiments) are proposed: (1) To define the reliability of the dual stable tracer technique for estimating lactose digestion in 5 preterm infants less than 32 wk post-conceptional age. (2) In 10 preterm infants less than 32 wk post-conceptional age: to define a point estimate for lactose digestion; to assess the effect of doubling the lactose intake on lactose digestion; to estimate the contribution of lactose-derived glucose and galactose to the systemic rate of appearance of glucose; and, using the above data, to assess hepatic glucose output. (3) By studying 5 additional infants, to complete the definition of a point estimate of lactose digestion in preterm infants > 32 wk post-conceptional age. (4) To define a point estimate of lactose digestion in 5 preterm infants less than 32 wk post- conceptional age fed human milk. The Secondary Aim is to determine the relationship of the lactose digestibility coefficient to the rate of breath H2 excretion (measured using a newly developed flow-through system). This study may be important to understanding the metabolism of lactose in preterm infants and should have relevance to the further development of feeding strategies which minimize formula intolerance and the risk of necrotizing enterocolitis especially in premature infants born prior to 30 wk gestational age.

在32-34周之前，胎儿肠乳糖酶活性极低妊娠，但此后似乎迅速上升。呼吸H2 浓度和乙酸全身产生的速率很高早产婴儿32-36 WK孕妇表明乳糖在结肠中大部分发酵，但对生长和乳糖的研究耐受性暗示乳糖水解在产后更有效生命比这些间接发酵活性指数所预测的。在本赠款的最后一年，这是一种双重稳定示踪技术用于估计体内乳糖消化系数（水解）早产儿33-34周孕年。基于在初始值（范围：0.8-1.2）上，假设乳糖消化是有效的（> 0.8）的早产儿> 32周概念时代（目标3）。该提议的主要假设在早产儿中乳糖消化次数小于32周概念年龄：（1）乳糖水解系数<0.80 并取决于乳糖摄入量。（2）在乳糖摄入量通常被这样的婴儿摄入，进入循环速率乳糖来源的葡萄糖不足以抑制（通过胰岛素分泌）肝葡萄糖输出。要解决这些假设，四个提出了主要特定目的（实验）：（1）定义双重稳定示踪技术用于估计乳糖的可靠性概念后年龄小于32周的5名早产儿的消化。（2）在10个早产儿中，孕年小于32周的婴儿：定义乳糖消化的点估计；评估将乳糖消化的乳糖摄入量加倍；估计乳糖衍生的葡萄糖和半乳糖对全身性的贡献葡萄糖的外观速率；并且，使用上述数据评估肝葡萄糖输出。（3）通过研究另外5个婴儿完成乳糖消化的点估计的定义早产儿> 32周后年龄。（4）定义一个点 5位早产儿的乳糖消化估计值小于32周构思时代喂了人牛奶。次要目的是确定乳糖消化率系数与速率的关系呼吸H2排泄（使用新开发的流通测量系统）。这项研究对于理解的代谢可能很重要早产儿的乳糖，应与进一步相关制定喂食策略，以最大程度地减少公式不耐受和坏死性小肠结肠炎的风险，尤其是在早产儿中出生于30周之前的胎龄。