Contribution of individual organ mass loss to weight loss-associated decline in resting energy expenditure
Contribution of individual organ mass loss to weight loss-associated decline in resting energy expenditure
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DOI：
10.3945/ajcn.2008.27402
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发表时间：
2009-10-01
影响因子：
7.1
通讯作者：
Mueller, Manfred J.
中科院分区：
文献类型：
--
作者：
Bosy-Westphal, Anja;Kossel, Elke;Mueller, Manfred J.
背景资料：体重减轻导致静息能量消耗（REE）降低，与无脂肪质量（FFM）和脂肪质量（FM）的减少无关，但FFM组成变化的影响尚不清楚。目的：我们假设，随着体重减轻，FFM调整后的REE减少，部分原因是FFM中高代谢活性成分的不成比例的减少。设计：45名超重和肥胖妇女[体重指数（kg/m2）：28.7 - 46.8]，年龄22-46岁，接受低热量饮食12.7 +/- 2.2周。通过磁共振成像、双能X线吸收法和四室模型测量身体成分。结果：体重减轻9.5 ± 3.4 kg（FM 8.0 ± 2.9 kg，FFM 1.5 ± 3.1 kg）。观察到REE（-8%）、游离三碘甲状腺原氨酸浓度（-8%）、肌肉（-3%）、心脏（-5%）、肝脏（-4%）和肾脏质量（-6%）降低（均P < 0.05）。器官质量的相对损失显著高于（P < 0.01）低代谢活性FFM组分（肌肉、骨和残留质量）的变化。体重减轻后，REEm 2 REEc从0.24 ± 0.58 MJ/d降至0.01 ± 0.44 MJ/d（P = 0.01），并与游离三碘甲状腺原氨酸浓度的降低相关（r = 0.33，P < 0.05）。具有高适应性产热作用的女性（定义为REEm 2 REEc < -0.17 MJ/d）体重减轻较少，FFM、肝脏和肾脏质量保持不变。结论：体重减轻后，几乎50%的REEm下降是由FFM和FM的损失造成的。通过考虑单个器官的重量，由身体组成解释的REEm的变异性增加到60%。美国临床营养杂志2009;90：993-1001。
Background: Weight loss leads to reduced resting energy expenditure (REE) independent of fat-free mass (FFM) and fat mass (FM) loss, but the effect of changes in FFM composition is unclear.Objective: We hypothesized that a decrease in REE adjusted for FFM with weight loss would be partly explained by a disproportionate loss in the high metabolic activity component of FFM.Design: Forty-five overweight and obese women [body mass index (in kg/m(2)): 28.7 46.8] aged 22-46 y followed a low-calorie diet for 12.7 +/- 2.2 wk. Body composition was measured by magnetic resonance imaging, dual-energy X-ray absorptiometry, and a 4-compartment model. REE measured by indirect calorimetry (REEm) was compared with REE calculated from detailed body-composition analysis (REEc) by using specific organ metabolic rates (ie, organ REE/mass).Results: Weight loss was 9.5 +/- 3.4 kg (8.0 +/- 2.9 kg FM and 1.5 +/- 3.1 kg FFM). Decreases in REE (-8%), free triiodothyronine concentrations (-8%), muscle (-3%), heart (-5%), liver (-4%), and kidney mass (-6%) were observed (all P < 0.05). Relative loss in organ mass was significantly higher (P < 0.01) than was the change in low metabolically active FFM components (muscle, bone, and residual mass). After weight loss, REEm 2 REEc decreased from 0.24 +/- 0.58 to 0.01 +/- 0.44 MJ/d (P = 0.01) and correlated with the decrease in free triiodothyronine concentrations (r = 0.33, P < 0.05). Women with high adaptive thermogenesis (defined as REEm 2 REEc < -0.17 MJ/d) had less weight loss and conserved FFM, liver, and kidney mass.Conclusions: After weight loss, almost 50% of the decrease in REEm was explained by losses in FFM and FM. The variability in REEm explained by body composition increased to 60% by also considering the weight of individual organs. Am J Clin Nutr 2009;90:993-1001.