Shirley Meghan K, Arthurs Owen J, Seunarine Kiran K, Cole Tim J, Eaton Simon, Williams Jane E, Clark Chris A, Wells Jonathan C K
UCL Great Ormond Street Institute of Child Health, London, UK.
Department of Radiology, Great Ormond Street Hospital, London, UK.
Eur J Clin Nutr. 2019 Aug;73(8):1164-1171. doi: 10.1038/s41430-018-0362-0. Epub 2018 Nov 7.
BACKGROUND/OBJECTIVES: Major organ-specific and tissue-specific metabolic rate (K) values were initially estimated using in vivo methods, and values reported by Elia (Energy metabolism: tissue determinants and cellular corollaries, Raven Press, New York, 1992) were subsequently supported by statistical analysis. However, the majority of work to date on this topic has addressed individuals of European descent, whereas population variability in resting energy metabolism has been reported. We aimed to estimate K values in South Asian females.
SUBJECTS/METHODS: This cross-sectional study recruited 70 healthy young women of South Asian ancestry. Brain and organs were measured using magnetic resonance imaging, skeletal muscle mass by dual-energy X-ray absorptiometry, fat mass by the 4-component model, and whole-body resting energy expenditure by indirect calorimetry. Organ and tissue K values were estimated indirectly using regression analysis through the origin. Preliminary analysis suggested overestimation of heart mass, hence the modeling was repeated with a literature-based 22.5% heart mass reduction.
The pattern of derived K values across organs and tissues matched that previously estimated in vivo, but the values were systematically lower. However, adjusting for the overestimation of heart mass markedly improved the agreement.
Our results support variability in K values among organs and tissues, where some are more metabolically "expensive" than others. Initial findings suggesting lower organ/tissue K values in South Asian women were likely influenced by heart mass estimation bias. The question of potential ethnic variability in organ-specific and tissue-specific energy metabolism requires further investigation.
背景/目的：主要器官特异性和组织特异性代谢率（K）值最初是使用体内方法估计的，随后埃利亚（《能量代谢：组织决定因素和细胞推论》，拉文出版社，纽约，1992年）报告的值得到了统计分析的支持。然而，迄今为止关于这个主题的大多数研究都针对欧洲血统的个体，而静息能量代谢的人群变异性已有报道。我们旨在估计南亚女性的K值。
对象/方法：这项横断面研究招募了70名南亚血统的健康年轻女性。使用磁共振成像测量大脑和器官，通过双能X线吸收法测量骨骼肌质量，采用四成分模型测量脂肪量，并通过间接测热法测量全身静息能量消耗。通过原点回归分析间接估计器官和组织的K值。初步分析表明心脏质量估计过高，因此在心脏质量减少22.5%的基础上重复建模。
各器官和组织得出的K值模式与先前体内估计的模式相符，但这些值系统性地更低。然而，对心脏质量估计过高进行校正后，一致性显著改善。
我们的结果支持器官和组织间K值存在变异性，其中一些器官和组织的代谢“成本”高于其他器官和组织。最初表明南亚女性器官/组织K值较低的发现可能受到心脏质量估计偏差的影响。器官特异性和组织特异性能量代谢中潜在种族变异性的问题需要进一步研究。
