Exploring Growth Energy Expenditure in Normal-Weight and Overweight Children

探索正常体重和超重儿童的生长能量消耗

• 批准号: 7389520
• 负责人: ZIMIAN WANG
• 金额: $ 19.92万
• 依托单位: ST. LUKE'S-ROOSEVELT INST FOR HLTH SCIS
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7389520
• 关键词: Adult; Affect; African American; Age; Body Composition; Body measure procedure; Cells; Child; Childhood; Count; Data; Dual-Energy X-Ray Absorptiometry; Energy Metabolism; Fatty acid glycerol esters; Gender; Goals; Growth; Indirect Calorimetry; Individual; Linear Regressions; Magnetic Resonance Imaging; Maintenance; Measures; Metabolic; Minerals; Modeling; Nutritional; Organ; Overweight; Potassium; Prevalence; Proteins; Rate; Regression Analysis; Research Project Grants; Solid; Sum; Testing; Time; Tissues; Weight; Weight Gain; aged; base; bone; boys; cost; day; extracellular; man; neuronal cell body; soft tissue

DESCRIPTION (provided by applicant): Pediatric overweight, defined as BMI >= 95th percentile for the same age and gender, is one of the most prevalent nutritional problems affecting children. Prevalence estimates show a substantial increase of childhood overweight in the U.S. from 4.6% in 1970 to 15.5% in 2000. The goal of this proposed research project is to describe changes in body composition at the cellular level and to estimate the energy costs associated with these changes in normal-weight and overweight children. The energy cost of growth has two components: 1) growth energy expenditure (GEE) for synthesizing body cell mass (BCM) and extracellular components, and 2) the energy stored (SE) in the cells, basically as fat and protein. The energy costs of 9.4 kcal/g for fat storage and 4.6 kcal/g for protein storage have been established for the SE component. However, the GEE component during growth has never been studied quantitatively. Although it is recognized that overweight children gain excessive weight, little is known about the difference in GEE between overweight and normal-weight children. This study is based on a conceptual model that GEE is equal to the difference between basal energy expenditure (BEE) and maintenance energy expenditure (MEE), i.e., GEE = BEE - MEE. BEE can be measured by indirect calorimetry, and MEE can be estimated by a recently established cellular level MEE model based on organ and tissue masses measured by MRI (Wang et al., Am J Clin Nutr 2005;81:799). We will compare GEE between overweight and normal-weight children, and explore the association between GEE and the gains of BCM and extracellular solids (ECS, e.g., bone). We will test two hypotheses: 1) the gains of BCM and ECS are major contributors of GEE; and 2) overweight children spend a different amount of energy to construct BCM than normal-weight children of same age and gender. If the hypotheses are correct, a multiple regression analysis model including gains of BCM and ECS as independent variables should explain a large fraction of the variance in GEE. Accordingly, we could fully explain the well-known phenomenon that children have a higher BEE/FFM ratio (-64 kcal/kg per day for a 0.5 yr-old child) than do adults (-30 kcal/kg per day for adult man). Therefore, this study has the potential to answer an important question regarding the energy cost for synthesizing new BCM, and to contribute to our understanding of energy metabolism in growing normal-weight and overweight children.

描述（由申请人提供）：儿童超重，定义为相同年龄和性别的BMI >=第95百分位数，是影响儿童的最普遍的营养问题之一。患病率估计显示，美国儿童超重率从1970年的4.6%大幅增加到2000年的15.5%。这项研究项目的目的是描述细胞水平上身体成分的变化，并估计正常体重和超重儿童与这些变化相关的能量成本。生长的能量成本有两个组成部分：1）用于合成体细胞质量（BMI）和细胞外成分的生长能量消耗（GEE），以及2）细胞中储存的能量（SE），基本上是脂肪和蛋白质。已确定SE组分的脂肪储存能量成本为9.4 kcal/g，蛋白质储存能量成本为4.6 kcal/g。然而，生长过程中的GEE组件从来没有被定量研究。虽然人们认识到超重儿童体重增加过多，但对超重儿童和正常体重儿童之间GEE的差异知之甚少。这项研究是基于一个概念模型，即GEE等于基础能量消耗（BEE）和维持能量消耗（BEE）之间的差异，即，GEE = BEE -BEE。BEE可以通过间接量热法测量，并且BEE可以通过最近建立的基于通过MRI测量的器官和组织质量的细胞水平的BEE模型来估计（Wang等人，Am J Clin Nutr 2005;81：799）。我们将比较超重和正常体重儿童的GEE，并探索GEE与BCM和细胞外固体（ECS，例如，骨）。我们将测试两个假设：（1）超重儿童和正常体重儿童在建构认知能力时所消耗的能量不同。如果假设是正确的，一个多元回归分析模型，包括增益的GEE和ECS作为自变量应解释一个大部分的方差。因此，我们可以充分解释众所周知的现象，即儿童的BEE/FFM比率（0.5岁儿童每天-64千卡/千克）高于成人（成人每天-30千卡/千克）。因此，这项研究有可能回答一个重要的问题，即合成新的维生素A的能量成本，并有助于我们了解正常体重和超重儿童的能量代谢。