ENERGY EXPENDITURE IN HEALTHY CHILDREN AND CHILDREN WITH RETT SYNDROME

健康儿童和患有 RETT 综合征的儿童的能量消耗

• 批准号: 6277982
• 负责人: KATHLEEN J MOTIL
• 金额: $ 2.57万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-12-01 至 1998-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6277982
• 关键词: Rett syndrome; bioenergetics; child (0-11); child physical development; clinical research; developmental nutrition; diet therapy; dietary proteins; human subject; human therapy evaluation; nutrient intake activity; nutrition disorders; nutrition related tag; postnatal growth disorder; tube feeding

Growth failure is a major complication of Rett Syndrome (RS). It is our hypothesis that dietary energy insufficiency relative to energy needs is the primary cause of growth failure. Altered partitioning of energy balance, i.e., increased energy expenditure due to involuntary motor activity, is the suspected mechanism of the greater energy needs. Thus, the long-term objective of this proposal is to identify the mechanism by which the partitioning of energy balance in RS girls is altered and to estimate its contribution to the overall energy requirement of these childred. The specific aims of the proposal are: 1) to determine whether total daily energy expenditure in RS girls is higher than that in healthy girls; 2) to determine whether the components of energy expenditure, measured by sleeping and quietly and actively awake metabolic rates, in RS girls are increased compared with those in healthy controls; 3) to determine whether dietary energy intakes in RS girls are sufficient to meet the energy demands of involuntary motor activity compared with those of healthy girls; and 4) to determine whether dietary energy in an amount that exceeds measured total daily energy expenditure is sufficient to reverse a)growth failure, measured by height and weight velocities, skinfold thicknesses, and muscle circumferences, and b)the abnormalities in the components of energy expenditure measured by sleeping and quickly and actively awake metabolic rates, after nutritional intervention in RS girls; and 5) to determine whether the absolute amount or proportion of energy expended in repetitive motor activity increases after nutritional rehabilitation in RS girls. Energy balance will be studied in 2 groups of subjects: 1) RS girls and 2) healthy controls. RS girls also will be studied after one year of nutritional rehabilitation via enteral tube feedings. To date, we studied 11 RS girls and 9 healthy controls. The results of the energy studies in RS and healthy girls are summarized as follows: 1) The clinical features of growth failure and malnutrition were present in all Rett girls. The Rett girls were stunted and wasted by Z-score criteria and fit the classification for first degree acute and chronic malnutrition by Waterlow's criteria. The growth and nutritional characteristics differed significantly between the RS girls and the healthy controls. 2) Body weight was significantly lower in RS girls than in healthy controls. This difference was the result of a significant reduction of the lean body mass, particularly the muscle of the lower, but not upper, extremities, as opposed to body fat. The pronounced reduction of lean body mass in the absence of equal or greater losses of body fat in the RS girls, was an unexpected finding of this project. 3) TDEE and SMR, measured by whole room calorimetry were 33% lower in RS girls than in healthy age-matched, as well as lean body mass-matched, controls. 4) Energy expenditure during REM sleep was slightly less, albeit not significant, than that measured during NREM sleep or in the basal state. 5) The ratio of TDEE to SMR, an indicator of daily physical activity, and the amount of awake time spent in activity, determined by 24-hr activity records, were not significantly different between the RS girls and the healthy controls. 6)Dietary energy intakes were significantly lower in the RS girls than in the healthy controls. 7) Nitrogen intakes and urinary nitrogen losses were significantly lower in the RS girls than in the healthy controls. Urinary nitrogen loses showed a significant positive linear relationship with dietary nitrogen and energy intakes in both groups of girls. Although apparent nitrogen balance was lower in the RS girls than in the healthy controls, these differences were not significantly different. RS girls were in positive apparent nitrogen balance despite that pronounced wasting of lean body mass, particularly the muscle of the lower extremities. At present, 11 RS girls have entered the refeeding phase of the study: 7 receive supplemental feedings through a gastrostomy button and 4 receive oral supplementation alone. The results of the refeeding studies are summarized as follows:1)Height (or length) velocities were 33% greater and weight velocities were at least threefold greater during the post than pre-supplmentation period. Although linear growth rates were similar between both feeding groups, the rate of weight gain was two-fold greater in the RS girls who received enteral (gastrostmy button), as opposed to oral, supplementation. 2)Weight gain was comprised equally of lean body mass and body fat, regardless of the mode of refeeding. Lean body mass, expressed as a proportion of body weight, decreased by 4% to 9% with nutritional supplementaion, while body fat, expressed as a proportion of body wieght, increased by the same percentage. The significance of our study is that it is the first to establish the nutritional basis of growth failure in RS girls. Our findings thus far demonstrate that the repetitive, involuntary motor movements of RS girls do not increase their total daily energy expenditure, and therefore, are not casually related to their growth failure. Of interest to us, however, is the apparent positive nitrogen balance in the presence of pronounced wasting of lean body mass, particularly the muscles of the lower extremities. We presume that the reductions of total daily energy expenditure, sleeping metabolic rates, and urinary nitrogen losses serve as compensatory mechanisms that permit the channeling of available, albeit reduced, dietary energy and protein into metabolic pathways that support essential physiologic functions of the body. Thus, our studies suggest that energy and protein are limiting nutrients in RS girls because of inadequeste dietary intakes. The observation that dietary energy and protein supplementation improved linear growth and led to the deposition of lean body mass and body fat in the RS girls supports our suppositions. We anticipate that early, aggressive nutritional intervention will optimize the nutritional stuatus and physical performance of these girls, as well as reduce the morbidity and mortality associated with nutritional deprivation.

生长障碍是雷特综合征 (RS) 的主要并发症。 这是我们的 膳食能量相对于能量需求不足的假设 是生长失败的主要原因。 改变能量分配 平衡，即由于无意识运动而增加的能量消耗 活性，是更大能量需求的怀疑机制。 因此， 该提案的长期目标是确定机制 RS 女孩的能量平衡分配被改变， 估计其对这些总体能源需求的贡献 儿童。 该提案的具体目标是： 1）确定RS女孩的每日总能量消耗是否为 高于健康女孩； 2）判断是否 能量消耗的组成部分，通过睡眠和安静来衡量 与其他女孩相比，RS 女孩主动清醒时的代谢率有所增加 健康对照者； 3）判断膳食是否有能量 RS女孩的摄入量足以满足 与健康女孩的不自主运动活动相比；和 4) 确定膳食能量是否超过测量值 每日总能量消耗足以逆转 a) 生长 失败，通过高度和重量速度、皮褶厚度来测量， 和肌肉周长，以及 b) 各组成部分的异常 通过睡眠和快速主动的清醒来衡量能量消耗 对RS女孩进行营养干预后的代谢率； 5) 到 确定消耗的能量的绝对量或比例 营养康复后重复性运动活动增加 在RS女孩中。 能量平衡将在两组科目中进行研究： 1) RS 女孩和 2) 健康对照。 RS女孩也将被研究 通过肠内管饲进行营养康复一年后。 迄今为止，我们研究了 11 名 RS 女孩和 9 名健康对照。 结果 RS和健康女孩的能量研究总结如下： 1）存在生长障碍和营养不良的临床特征 在所有雷特女孩中。 雷特家的女孩们因 Z 分数而发育不良并浪费了精力 标准并符合一级急性和慢性分类 根据沃特洛标准，营养不良。 生长与营养 RS女孩和RS女孩之间的特征存在显着差异 健康的控制。 2) RS女孩的体重明显较低 与健康对照组相比。 这种差异是由于 显着减少去脂体重，特别是肌肉 下肢而非上肢，与身体脂肪相反。 这 在没有同等或 RS 女孩的体脂损失更大，这是一个意外的发现 这个项目的。 3) TDEE 和 SMR，通过全室量热法测量 RS 女孩的体重比健康同龄女孩低 33%，而且身材苗条 体重匹配、控制。 4) 快速眼动睡眠期间的能量消耗为 比 NREM 期间测量的值略少，尽管不显着 睡眠或基础状态。 5）TDEE与SMR的比值，一个指标 日常体力活动量，以及清醒时间花在 根据 24 小时活动记录确定的活动不显着 RS 女孩和健康对照组之间存在差异。 6）饮食 RS女孩的能量摄入量明显低于对照组女孩 健康的控制。 7) 氮摄入量和尿氮损失量 RS 女孩中的值显着低于健康对照组。 尿氮损失呈显着正线性关系 两组女孩的膳食氮和能量摄入量。 尽管RS女孩的表观氮平衡低于对照组女孩 健康对照组，这些差异没有显着差异。 尽管如此，RS 女孩仍处于正表观氮平衡状态 瘦体重明显消耗，尤其是肌肉 下肢。 目前，已有11名RS女孩进入复喂期 研究阶段：7 人通过 胃造口按钮和 4 人单独接受口服补充剂。 这 重新喂养研究的结果总结如下：1）身高（或 长度）速度增加 33%，重量速度至少增加 补充后期间的数量是补充前的三倍。 尽管两个喂养组之间的线性增长率相似， RS 女孩的体重增加速度是其两倍 接受肠内注射（胃按钮），而不是口服， 补充。 2）体重增加与去脂体重相等 和身体脂肪，无论重新喂养的方式如何。 去脂体重， 以占体重的比例表示，下降 4% 至 9% 营养补充，而体脂肪，以比例表示 体重增加了相同的百分比。 意义 我们的研究首次建立了营养基础 RS 女孩生长迟缓。 迄今为止我们的研究结果表明 RS 女孩的重复性、无意识运动没有增加 他们每天的总能量消耗，因此，并不是随便 与他们的成长失败有关。 然而，我们感兴趣的是 在存在明显消耗的情况下出现明显的正氮平衡 瘦体重，特别是下肢的肌肉。 我们假设每日总能量消耗的减少， 睡眠代谢率和尿氮损失 补偿机制，允许引导可用的、 尽管减少，膳食能量和蛋白质进入代谢途径， 支持身体的基本生理功能。 因此，我们的研究 表明能量和蛋白质限制了 RS 女孩的营养 因为饮食摄入不足。 饮食观察发现 能量和蛋白质补充改善了线性生长并导致 RS 女孩中瘦体重和体脂的沉积支持了我们的研究 假设。 我们预计早期、积极的营养 干预将优化营养状况和身体状况 这些女孩的表现，以及降低发病率和 与营养缺乏相关的死亡率。