ENERGY EXPENDITURE AND BODY COMPOSITION

能量消耗和身体成分

• 批准号: 2134077
• 负责人: REINALDO FIGUEROA-COLON
• 金额: $ 8.96万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 1999-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2134077
• 关键词: African American; adipose tissue; bioenergetics; blood pressure; body composition; body physical activity; calorimetry; carbohydrate metabolism; caucasian American; child (0-11); female; glucose tolerance test; human subject; hydrogen; lipid metabolism; longitudinal human study; obesity; oxygen; stable isotope double label

Obesity affects 25% to 30% of children. After adolescence african- american females have a higher prevalence of obesity, and as adults obese african-american females have increased morbidity and mortality compared to caucasian females. Obesity is caused by increased energy intake and/or decreased energy expenditure (EE). 24-hour BE can be divided into three components: resting EE, thermic effect of food, and energy cost of activity. Total BE can be determined in free-living subjects using the doubly-labeled (2H2 18O) stable isotope of water and in confined subjects using whole-room indirect calorimetry. 2H2 18O measures total EE; indirect calorimetry measures total EE and its components, and fuel utilization. The difference between the total EE from the two methods is an estimate of free-living physical activity. Low EE has been demonstrated before the period of rapid weight gain in pre-obese caucasian infants and children (aged 4 to 5 years), and in adult Pima Indians. In obese adult Pima Indians reduced EE aggregated in families and may be the physiologic basis for the inheritance of obesity. Other studies in Pima Indians suggest that reduced oxidation of fat leads to a positive fat balance, which may be another factor in the development of obesity. It is unknown 1) if EE is decreased in pre-obese prepubertal females (african-american or caucasian), and 2) which component of EE is decreased. The main hypothesis of this study is that low EE (adjusted for body composition) and a low rate of fat oxidation will predict more rapid weight gain in african-american or caucasian females with obese parents than in similar females with no familial predisposition to obesity. The second hypothesis is that low resting EE and low habitual activity are the EE components that best predict rapid weight gain. Using state-of-the-art methods of whole-room indirect calorimetry (never used in this age group) and 2H2 180, the components of 24-hour EE and habitual physical activity will be determined. Two baseline analyses (1-month apart) of EE and fat oxidation of 52 prepubertal nonobese african- american or caucasian females, aged 6 to 9 years, will be the starting point for a longitudinal follow-up of at least 2.5 years. 26 children (non-pre-obese) will be selected as having both biological parents with a measured body mass index (BMI) < 27.5 kg/m2. The other 26 children (pre-obese) will be selected as having both parents with a measured BMI > 30 kg/m2. All children will undergo repeat assessments of blood pressure, glucose tolerance, body fat pattern, and body composition after 2.5 years. Analyses of the data will allow comparisons of baseline EE and fat oxidation in children of nonobese and obese parents, as well as the relationship to subsequent weight gain and body fat pattern over at least 2.5 years. This study will provide valuable information for understanding which factors predispose certain individuals to obesity. This information is crucial to develop strategies for obesity prevention.

肥胖影响25％至30％的儿童。青春期非洲 - 美国女性的肥胖症患病率更高，成年人肥胖 比较的非裔美国女性发病率和死亡率增加 对高加索女性。肥胖是由能量摄入量增加和/或 能源支出减少（EE）。 24小时可以分为三个 组件：休息EE，食物的热效应以及能量成本 活动。可以使用 双标记（2H2 18O）稳定的水和受试者中的同位素 使用整个房间间接量热法。 2H2 18O测量总EE； 间接量热法测量总EE及其组件和燃料 利用率。两种方法的总EE之间的差异是 自由生活活动的估计。 在快速体重增加期之前，已经证明了低EE 肥胖的高加索婴儿和儿童（4至5岁），在 成人皮马印第安人。在肥胖的成年PIMA印第安人降低了EE 家庭，可能是继承肥胖的生理基础。 PIMA印第安人的其他研究表明，脂肪铅的氧化减少 达到积极的脂肪平衡，这可能是发展的另一个因素 肥胖。 这是未知的1）如果EE在肥胖前青春期前女性中减少 （非裔美国人或高加索人），以及2）EE的哪个组成部分 减少。 这项研究的主要假设是低EE（调整后 对于身体组成）和低脂肪氧化速率将预测更多 肥胖的非裔美国人或高加索女性的体重快速增加 父母比在没有家族倾向的类似女性中 肥胖。第二个假设是低静止EE和低习惯 活性是最能预测重量快速增加的EE组件。使用 整个房间间接量热法的最先进方法（从未使用过 在这个年龄段）和2H2 180，EE 24小时的组成部分 将确定体育活动。两个基线分析（1个月 EE的EE和52个前非肥胖非洲的EE和脂肪氧化 6至9岁的美国或高加索女性将成为起点 纵向随访至少2。5年的点。 26个孩子 （非肥胖）将被选为拥有两个亲生父母 测得的体重指数（BMI）<27.5 kg/m2。其他26个孩子 （肥胖前）将被选为让父母都具有测量的BMI > 30 kg/m2。所有孩子都会重复评估血液 压力，葡萄糖耐量，体内脂肪图案和体内组成之后 2。5年。对数据的分析将允许比较基线EE和 非肥胖和肥胖父母的儿童的脂肪氧化以及 至少与随后的体重增加和体内脂肪模式的关系至少 2。5年。这项研究将提供有价值的信息以理解 哪些因素使某些人易于肥胖。此信息 对于制定预防肥胖症的策略至关重要。