INSULIN SENSITIVITY IN AFRICAN AMERICAN & CAUCAIAN CHILDREN WITH LOW BIRTH WEIGH

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。在几项调查中，低出生体重已被证明与生命后期胰岛素不敏感受损有关。这种关系可能是由于宫内生长迟缓，最终导致潜在的代谢异常。这种代谢异常和随后的疾病可能在非裔美国人中有所不同，但尚未进行系统的测试。在肥胖发展的关键时期，没有研究调查不同种族的儿童和青少年低出生体重与胰岛素敏感性的关系。此外，大多数关于低出生体重与胰岛素敏感性关系的研究使用了现场方法。很少有人用H-MRS评价骨骼肌的IMCL，也没有人评价肝内脂肪储存及其与胰岛素敏感性的关系。我们建议使用新颖的非侵入性技术来检查低出生体重对胰岛素敏感性的影响。我们希望在20名7-9岁的儿童中评估这些关系。这项研究的结果将提供关于低出生体重和种族使儿童易患胰岛素敏感性受损和最终肥胖和糖尿病的潜在机制的重要信息。该项目的目的是确认低出生体重与胰岛素敏感性在青春期前儿童中存在显著关系，如果存在，则确定这种关系是否在非裔美国人与白人儿童中更为明显。其次，我们将检查异位和腹部脂肪、能量代谢和心血管危险因素，探讨这些青春期前儿童低胰岛素敏感性的潜在机制。这些感兴趣的变量将在发展的关键时期（例如7-9年）进行测量，包括：FSIGTT对胰岛素的敏感性（假设一）2 .身体总脂肪（假设1）IMCL在骨骼和肝内脂肪储存中的作用（假设IIa）腹部脂肪MRI（假设IIb）通过REE和RQ（通风罩间接量热法）测定静息代谢（假设IIc）心血管疾病风险因素血脂(总胆固醇(TC)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)和血压。(Hpothesis IId)

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. Low birth weight has been shown to be associated with impaired insulin insensitivity later in life in several investigations. The relationship may be due to intrauterine growth retardation, which ultimately promotes a potential metabolic abnormality. This metabolic abnormality and subsequent disease may be different in African Americans but, this has not been tested systematically. No studies have examined the relationship of low birth weight to insulin sensitivity in children and adolescents from different ethnic groups during a critical period of obesity development. Futhermore, the majority of the studies concerning the relationship of low birth weight to insulin sensitivity utilized field methods. Few have used H-MRS to evaluate IMCL in skeletal muscle and none evaluate intrahepatic fat stores and their relation to insulin sensitivity. We propose to examine low birth weight with respect to insulin sensitivity using novel, non-invasive techniques. We wish to evaluate these relationships in 20 children, aged 7-9 years. The results of this study will provide important information concerning potential mechanisms by which low birth weight and ethnicity predispose children to impaired insulin sensitivity and ultimately obesity and diabetes. The objective of this project is to confirm that a significant relationship of low birth weight to insulin sensitivity exists in prepubertal children and, if so, to determine whether this relationship will be more pronounced in African American versus Caucasion children. Secondly, we will examine ectopic and abdominal fat, energy metabolism and cardiovascular risk factors to explore potential mechanisms of the low-insulin sensitivity observed in these prepubertal children. These variables of interest, which will be measured during a critical period of development, e.g. 7-9 years, include: 1. Insulin Sensitivity by FSIGTT (Hypothesis I) 2. Total body fat by DEXA (Hypothesis I) 3. IMCL in skeletal and intrahepatic fat stores by (Hypothesis IIa) 4. Abdominal fat by MRI (Hypothesis IIb) 5. Resting metabolism by REE and RQ (ventilated hood indirect calorimetry) (Hypothesis IIc) 6. Cardiovascular Disease Risk Factor by lipid profiles (Total Cholesterol [TC], High Density Lipoprotein [HDL], Low Density Lipoprotein [LDL] and resting blood pressure. (Hpothesis IId)