IMPACT OF REDUCED GLUCOSE INFUSION RATE AND INSULIN INFUSION, RESPECTIVELY, O

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 摘要 极低出生体重（ELBW）新生儿（出生体重<1000 g），通常需要全肠外营养（TPN）在他们的疾病过程中，直到他们的能力耐受肠内喂养建立良好。 这些婴儿有葡萄糖代谢紊乱和能量补充不足的风险。 高血糖的发生率很高（50-80%）。 通常，根据高血糖症的严重程度和患者的临床表现，通过降低葡萄糖输注速率和/或静脉注射胰岛素来治疗这些高血糖值。 我们还不知道胰岛素的生成是否受到葡萄糖和胰岛素浓度变化的影响，这些变化是由葡萄糖输注速率降低或固定的胰岛素输注引起的。 本研究的目的是确定将葡萄糖输注速率降低到正常葡萄糖转换速率的一半和固定胰岛素输注对ELBW婴儿葡萄糖和蛋白质代谢的影响。 对我们来说，了解这些非常小的婴儿的葡萄糖代谢的生理学是很重要的，因为它将使我们能够设计一种适当的肠外营养，使这些婴儿血糖正常，同时提供足够的能量摄入。 假设 1. 由于葡萄糖输注速率降低至3 mg/kg/min，血糖和胰岛素水平降低时，新生儿的发生率不会发生变化。 2. 足以使血浆胰岛素浓度达到高生理范围（~ 80 - 100 uU/ml）的胰岛素固定输注将： a. 不能急性抑制新生儿的发生率 B. 无论体重、胎龄和临床状态如何，均增加葡萄糖利用率，但葡萄糖利用率的增加将与体重成正比 C.增加蛋白质合成 具体目标 本研究的目的是确定葡萄糖和胰岛素浓度变化的代谢效应，这些变化是由于降低葡萄糖输注速率以对应于正常葡萄糖转换率的一半（同时维持肠外脂质和氨基酸的输注速率不变）以及固定胰岛素输注对极低出生体重儿葡萄糖利用率和产生率的影响。 这将使用稳定同位素-GCMS技术进行。 这将使我们能够确定不同葡萄糖输注速率和血浆胰岛素水平对患病新生儿的代谢影响。

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. ABSTRACT Extremely low birth weight (ELBW) newborns (birth weight <1000g), 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 are at risk of disturbed glucose metabolism and inadequate energy supplementation. They have a very high incidence of hyperglycemia (50-80%). Usually, these high blood glucose values are being treated with reduction of the glucose infusion rate and/or with intravenous insulin, depending on the severity of the hyperglycemia and the patient's clinical picture. We do not know whether gluconeogenesis is affected by the changes in glucose and insulin concentrations resulting from reduced glucose infusion rates or by a fixed insulin infusion. the purpose of this study is to determine the effect of reducing the glucose infusion rate to correspond to half the normal glucose turn over rate and of a fixed insulin infusion, on glucose and protein metabolism in ELBW infnats. It is important for us to learn about the physiology of glucose metabolism in these very small infants for it will enable us to design an adequate parenteral nutrition that renders these infants normoglycemic while providing a sufficient energy intake. HYPOTHESIS 1. Rates of gluconeogenesis do not change in response to a decrease in blood levels of glucose and insulin, resulting from a decrease in the glucose infusion rate to 3mg/kg/min. 2. A fixed infusion of insulin sufficient to achieve a plasma insulin concentration in the high physiologic range (-80-100uU/ml) will: a. Not acutely suppress rates of gluconeogenesis b. Increase glucose utilization regardless of body weight, gestational age and clinical status, but increasing the glucose utilization will be proportional to body weight c. Increase protein synthesis SPECIFIC AIMS The purpose of this study is to determine the metabolic effects of changes in glucose and insulin concentration resulting from reducing the infusion rate of glucose to correspond to half normal glucose turnover (while maintaining the infusion rates of parenteral lipids and amino acids unchanged) and from a fixed insulin infusion on rates of glucose utilization and production in extremely low birth weight infants. This will be performed using Stable Isotope-GCMS techniques. This will allow us to determine the metabolic effects of different glucose infusion rates and plasma insulin levels in sick newborn infants.