GLUCOSE METABOLISM IN NEWBORN INFANTS WITH RESPIRATORY ILLNESS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 患病的新生儿，尤其是患有呼吸系统疾病的新生儿，在他们的病程中和直到他们对肠道喂养的耐受性良好之前，通常需要完全肠外营养(TPN)。这些婴儿，以及那些早产的婴儿，面临着葡萄糖代谢紊乱和能量补充不足的风险。为了防止低血糖和提供足够的能量摄入，这些新生儿中的一些常规接受两倍于周转率的葡萄糖输注(正常周转率：6-8毫克/公斤/分钟)。当这样做时，特别是在早产儿中，高血糖成为更常见的并发症。我们不知道改变葡萄糖输注速度如何影响患有呼吸系统疾病的新生儿的葡萄糖代谢和血糖水平。本项目的目的是确定不同的葡萄糖输注速率对患有严重肺部疾病的新生儿的葡萄糖、脂肪和蛋白质代谢的影响。对我们来说，了解这些患病新生儿的葡萄糖代谢生理学是很重要的，因为这将使我们能够制定足够的肠外营养，使这些婴儿保持正常血糖，因为这也将为他们提供足够的能量摄入。 假设 1.与6 mg/kg/min的TPN相比，常规TPN(通常以相当于正常葡萄糖周转率两倍的速率提供葡萄糖)更容易发生高血糖。葡萄糖输注率(正常葡萄糖周转率)。 2.呼吸系统疾病新生儿能够在6 mg/kg/min葡萄糖输注速率下维持正常血糖(同时保持肠外脂肪和氨基酸的输注速率不变)。 3.患有呼吸系统疾病的婴儿在接受常规的TPN时，葡萄糖的产生，特别是糖异生，并没有完全被抑制，TPN以两倍的正常周转率提供葡萄糖。 4.甘油是重要的糖异生底物。 5.在接受6 mg/kg/min葡萄糖的TPN治疗的患病婴儿中，全身蛋白质分解和氧化没有增加 具体目标 本研究的目的是利用已建立的稳定的同位素GCMS技术，确定常规TPN(以大约两倍的正常葡萄糖周转率提供葡萄糖)和降低葡萄糖输注速度以与正常葡萄糖周转相对应(同时保持肠外脂肪和氨基酸的输注速度不变)对患有IRDS、胎粪吸入和气胸等呼吸系统疾病的婴儿血糖、脂肪和蛋白质代谢的影响。这将使我们能够确定葡萄糖输注速度对患有呼吸系统疾病的新生儿的代谢影响。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Sick neonates, especialy those with respiratory illness, usually require Total Parenteral Nutrition (TPN) during the course of their illness and until their ability to tolerate enteral feeds is well established. These infants, as well as those born prematurely, are at risk of a disturbed glucose metabolism and an inadequate energy supplementation. In an effort to prevent hypoglycemia and to provide a sufficient energy intake, some of these neonates are routinely receiving glucose infusion rates of twice their turn over rate (normal turnover rate: 6-8mg/kg/min.). When this is done, particularly in very premature infants, hyperglycemia becomes a more frequent complication. We do not know how changing the glucose infusion rate affects the glucose metabolism and the blood glucose levels in newborns with respiratory illnesses. The purpose of this project is to determine the effects of different glucose infusion rates on glucose, lipid, and protein metabolism in newborn infants with severe pulmonary diseases. It is important for us to learn about the physiology of glucose metabolism in these sick neonates for it will enable us to formulate an adequate parenteral nutrition that renders these infants normoglycemic as it also would provide them with a sufficient energy intake. HYPOTHESIS 1. Hyperglycemia is more likely to occur while on routine TPN (usually providing glucose at rates corresponding to twice the normal glucose turnover rate) than on a TPN with a 6 mg/kg/min. glucose infusion rate (normal glucose turnover rate). 2. Newborn infants with respiratory illness are able to maintain normoglycemia during a 6mg/kg/min glucose infusion rate (while maintaining the infusion rates of parenteral lipids and amino acids unchanged). 3. Glucose production, particularly gluconeogenesis, is not completely suppressed in infants with respiratory illness while receiving a routine TPN providing glucose at twice normal turnover rate. 4. Glycerol is a significant gluconeogenic substrate. 5. Whole-body protein breakdown and oxidation is not increased in sick infants receiving a TPN providing glucose at 6mg/kg/min SPECIFIC AIMS The purpose of this study is to determine the effects of routing TPN (providing glucose at about twice normal turnover rates), and of reducing the infusion rate of glucose to correspond to the normal glucose turnover (while maintaining the infusion rates of parenteral lipids and amino acids unchanged) on glucose, lipid and protein metabolism in infants with respiratory illness such as IRDS, meconium aspiration and pneumothorax using established Stable Isotope-GCMS techniques. This will allow us to determine the metabolic effects of glucose infusion rate in sick newborn infants with respiratory illness.