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: 7191998
• 负责人: ZIMIAN WANG
• 金额: $ 24.39万
• 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 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7191998
• 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BMI和GT；=95百分位数，在相同的年龄和性别，是影响儿童最普遍的营养问题之一。流行率估计显示，美国儿童超重的比例从1970年的4.6%大幅上升到2000年的15.5%。这项拟议的研究项目的目标是在细胞水平上描述身体成分的变化，并估计与正常体重和超重儿童的这些变化相关的能量成本。生长的能量成本由两部分组成：1)用于合成体细胞质量(BCM)和胞外成分的生长能量支出(GEE)；2)细胞内储存的能量(SE)，基本上是以脂肪和蛋白质的形式存在的。建立了SE组分储存脂肪的能量成本为9.4千卡/克，储存蛋白质的能量成本为4.6千卡/克。然而，生长过程中的GEE成分从未被定量研究过。虽然超重儿童的体重增加是公认的，但超重儿童和正常体重儿童之间的GEE差异却知之甚少。本研究基于一个概念模型，即GEE等于基础能量消耗(BEE)和维护能量消耗(MEE)之差，即GEE=BEE-MEE。蜜蜂可以通过间接量热法测量，而MEE可以通过最近建立的基于MRI测量的器官和组织质量的细胞水平MEE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，例如骨骼)的增长之间的关联。我们将检验两个假设：1)BCM和ECS的收益是GEE的主要贡献者；2)超重儿童构建BCM所花费的能量与相同年龄和性别的正常体重儿童不同。如果假设是正确的，将BCM和ECS的收益作为自变量的多元回归分析模型应该可以解释GEE中的一大部分方差。因此，我们可以充分解释众所周知的现象，即儿童的蜜蜂/FFM比率(0.5岁儿童-千卡/千克/天)高于成年人(成人-30千卡/千克/天)。因此，这项研究有可能回答一个关于合成新的BCM的能量成本的重要问题，并有助于我们理解正常体重和超重儿童的能量代谢。