EFFECTS OF EXOGENOUS INSULIN ON PROTEIN METABOLISM IN EXTREMELY LBW INFANTS

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。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。所列机构为中心，不一定是研究者所在机构。出生后第一天的高血压在ELBW婴儿中很常见。据报道，在所有入住NICU的婴儿中，其发生率约为5%，在2000 g的婴儿中发生率高出18倍<1000g compared to those >。在ELBW婴儿中，即使在最低葡萄糖摄入量下也可能发生高血糖症。在这种情况下，许多中心给予胰岛素以避免渗透性利尿、高血糖症可能产生的不良CNS效应以及需要输送低摩尔浓度溶液以控制高血糖症。在这些情况下，胰岛素可有效降低高血糖症。由于新生儿期的高血糖通常是持续2-5天的短暂事件，因此在这种情况下使用胰岛素主要集中在液体和电解质管理上，而不是加强营养支持。然而，胰岛素对蛋白质代谢的影响在这一人群中并不清楚，唯一一项研究氨基酸动力学的研究表明，使用胰岛素没有合成代谢作用，但乳酸浓度显著增加。鉴于胰岛素在ELBW婴儿管理中的广泛使用，我们认为进一步描述胰岛素在当前临床实践中的作用是谨慎的。我们建议使用稳定同位素方法来研究胰岛素对胰岛素抵抗的早发性新生儿高血糖症中ELBW新生儿的葡萄糖和氨基酸代谢以及乳酸产生的影响。

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. Hyperglycemia in the first days of life is common in ELBW infants. It has been reported to have an incidence of approximately 5% in all infants admitted to the NICU, and to occur 18 times more commonly in infants <1000g compared to those >2000g. In ELBW infants, hyperglycemia can occur even on minimal glucose intakes. In this situation, many centers administer insulin to avoid osmotic diuresis, possible undesirable CNS effects of hyperglycemia, and the need to deliver hyposmolar solutions to control hyperglycemia. In these settings, insulin is effective in reducing hyperglycemia. Since this hyperglycemia in the immediate newborn period is usually a transient event lasting 2-5 days, the use of insulin in this setting is primarily focused on fluid and electrolyte management and not on advancing nutritional support. However, insulin's effect on protein metabolism is not well understood in this population, and the only study investigating amino acid kinetics suggests no anabolic effect but a marked increase in lactate concentration with insulin use. Given the widespread use of insulin in the management of ELBW infants, we feel it is prudent to further delineate insulin's effects as used in current clinical practice. We propose to use stable isotope methodology to investigate the effect of insulin on glucose and amino acid metabolism and lactate production in ELBW neonates in insulin-resistant early-onset neonatal hyperglycemia.