Brain and high metabolic rate organ mass: contributions to resting energy expenditure beyond fat-free mass
Brain and high metabolic rate organ mass: contributions to resting energy expenditure beyond fat-free mass
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DOI：
10.3945/ajcn.2009.28512
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发表时间：
2010-04-01
影响因子：
7.1
通讯作者：
Gallagher, Dympna
中科院分区：
文献类型：
--
作者：
Javed, Fahad;He, Qing;Gallagher, Dympna
背景：某些高代谢率器官（HMRO）质量的个体间差异在多大程度上介导静息能量消耗（REE）的变异性尚不清楚。
目的：本研究旨在探讨成人中HMRO质量的差异能解释多少REE的变异性，以及在对HMRO进行调整后，年龄、性别和种族是否能独立预测REE。
设计：对55名女性[30名非裔美国人，年龄为48.7±22.2岁（均值±标准差），25名白人，年龄为46.4±17.7岁]和32名男性（8名非裔美国人，年龄为34.3±18.2岁，24名白人，年龄为51.3±20.6岁）进行了横断面评估。通过磁共振成像测量肝脏、肾脏、脾脏、心脏和大脑的质量，通过双能X线吸收法测量脂肪和去脂体重（FFM）。通过间接测热法测量REE。
结果：由年龄（P = 0.001）、种族（P = 0.006）、性别（P = 0.31）、脂肪（P = 0.001）和FFM（P < 0.001）估算的REE占REE变异性的70%（调整后的R²）。将躯干HMRO（P = 0.001）和大脑（P = 0.006）加入模型后，解释的方差增加到75%，使得年龄、性别和种族的贡献在统计学上不显著，而脂肪和FFM仍有显著贡献（两者P < 0.05）。将大脑加入模型后，截距（69千卡·千克⁻¹·天⁻¹）与零一致，这表明体重为零时REE为零。
结论：HMRO质量相对较小的个体间差异显著影响REE，并降低了年龄、种族和性别在解释REE中的作用。REE随年龄增长而降低可能部分与FFM成分相对大小的年龄相关变化有关。《美国临床营养学杂志》2010年；91：907 - 912。
Background: The degree to which interindividual variation in the mass of select high metabolic rate organs (HMROs) mediates variability in resting energy expenditure (REE) is unknown.Objective: The objective was to investigate how much REE variability is explained by differences in HMRO mass in adults and whether age, sex, and race independently predict REE after adjustment for HMRO.Design: A cross-sectional evaluation of 55 women [30 African Americans aged 48.7 +/- 22.2 y (mean +/- SD) and 25 whites aged 46.4 +/- 17.7 y] and 32 men (8 African Americans aged 34.3 +/- 18.2 y and 24 whites aged 51.3 +/- 20.6 y) was conducted. Liver, kidney, spleen, heart, and brain masses were measured by magnetic resonance imaging, and fat and fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry. REE was measured by indirect calorimetry.Results: REE estimated from age (P = 0.001), race (P = 0.006), sex (P = 0.31), fat (P = 0.001), and FFM (P < 0.001) accounted for 70% (adjusted R 2) of the variability in REE. The addition of trunk HMRO (P = 0.001) and brain (P = 0.006) to the model increased the explained variance to 75% and rendered the contributions of age, sex, and race statistically nonsignificant, whereas fat and FFM continued to make significant contributions (both P < 0.05). The addition of brain to the model rendered the intercept (69 kcal . kg(-1) . d(-1)) consistent with zero, which indicated zero REE for zero body mass.Conclusions: Relatively small interindividual variation in HMRO mass significantly affects REE and reduces the role of age, race, and sex in explaining REE. Decreases in REE with increasing age may be partly related to age-associated changes in the relative size of FFM components. Am J Clin Nutr 2010; 91: 907-12.