Obesity Research Center, St Luke's-Roosevelt Hospital, Columbia University, College of Physicians and Surgeons, New York, NY, USA.
Am J Clin Nutr. 2010 Dec;92(6):1369-77. doi: 10.3945/ajcn.2010.29885. Epub 2010 Oct 20.
The specific resting metabolic rates (K(i); in kcal · kg(-1 )· d(-1)) of major organs and tissues in adults were suggested by Elia (in Energy metabolism: tissue determinants and cellular corollaries. New York, NY: Raven Press, 1992) to be as follows: 200 for liver, 240 for brain, 440 for heart and kidneys, 13 for skeletal muscle, 4.5 for adipose tissue, and 12 for residual organs and tissues. However, Elia's K(i) values have never been fully evaluated.
The objectives of the present study were to evaluate the applicability of Elia's K(i) values across adulthood and to explore the potential influence of age on the K(i) values.
A new approach was developed to evaluate the K(i) values of major organs and tissues on the basis of a mechanistic model: REE = Σ(K(i) × T(i)), where REE is whole-body resting energy expenditure measured by indirect calorimetry, and T(i) is the mass of individual organs and tissues measured by magnetic resonance imaging. With measured REE and T(i), marginal 95% CIs for K(i) values were calculated by stepwise univariate regression analysis. An existing database of nonobese, healthy adults [n = 131; body mass index (in kg/m²) <30] was divided into 3 age groups: 21-30 y (young, n = 43), 31-50 y (middle-age, n = 51), and > 50 y (n = 37).
Elia's K(i) values were within the range of 95% CIs in the young and middle-age groups. However, Elia's K(i) values were outside the right boundaries of 95% CIs in the >50-y group, which indicated that Elia's study overestimated K(i) values by 3% in this group. Age-adjusted K(i) values for adults aged >50 y were 194 for liver, 233 for brain, 426 for heart and kidneys, 12.6 for skeletal muscle, 4.4 for adipose tissue, and 11.6 for residuals.
The general applicability of Elia's K(i) values was validated across adulthood, although age adjustment is appropriate for specific applications.
Elia(1992 年,纽约,Raven 出版社:《能量代谢:组织决定因素和细胞推论》)提出,成年人主要器官和组织的特定静息代谢率(K(i),单位为千卡·千克(-1)·天(-1))如下:肝脏 200,大脑 240,心脏和肾脏 440,骨骼肌 13,脂肪组织 4.5,剩余器官和组织 12。然而,Elia 的 K(i)值从未被充分评估过。
本研究旨在评估 Elia 的 K(i)值在成年期的适用性,并探讨年龄对 K(i)值的潜在影响。
本研究采用一种新方法,基于一种机制模型评估主要器官和组织的 K(i)值:REE=Σ(K(i)×T(i)),其中 REE 是通过间接测热法测量的全身静息能量消耗,T(i)是通过磁共振成像测量的各个器官和组织的质量。通过测量 REE 和 T(i),采用逐步单变量回归分析计算 K(i)值的边际 95%置信区间。将一个现有的非肥胖、健康成年人数据库(n=131;体重指数(kg/m²)<30)分为 3 个年龄组:21-30 岁(年轻组,n=43)、31-50 岁(中年组,n=51)和>50 岁(n=37)。
在年轻和中年组中,Elia 的 K(i)值在 95%置信区间内。然而,在>50 岁组中,Elia 的 K(i)值超出了 95%置信区间的右侧边界,这表明在该组中 Elia 的研究高估了 K(i)值 3%。>50 岁成年人的年龄调整 K(i)值为:肝脏 194,大脑 233,心脏和肾脏 426,骨骼肌 12.6,脂肪组织 4.4,其余组织 11.6。
Elia 的 K(i)值在成年期具有普遍适用性,尽管在特定应用中需要进行年龄调整。