Advances in the understanding of specific metabolic rates of major organs and tissues in humans

作者：Mueller Manfred J; Wang ZiMian; Heymsfield Steven B; Schautz Britta; Bosy Westphal Anja

来源：Current Opinion in Clinical Nutrition and Metabolic Care, 2013, 16(5): 501-508.

DOI：10.1097/MCO.0b013e328363bdf9

• body composition
• fat-free mass
• MRI
• metabolically active body components
• resting energy expenditure

Purpose of reviewTo present recent evidence on organ and tissue metabolic rates in humans to explain the variance in resting energy expenditure (REE).Recent findingsIn humans, present knowledge on specific metabolic activities (i.e. ki-values) refers to seven organs and tissues - brain, heart, liver, kidneys, skeletal muscle, adipose tissue and residual mass - with ki-values of 240, 440, 200, 440, 13, 4.5 and 12kcal/kg/day, provided by Elia in 1992. Detailed body composition data, as derived from whole body MRI together with measurements of whole body REE, were used to validate ki-values in nonobese, healthy and middle-aged adults. There is no sex difference, but minor, that is 2 and 3% deviations are found for age above 55 years and obesity, respectively. By contrast, in adolescents, differences of about 100kcal/day or 7.3% of measured REE were observed. There is first evidence for changes in ki-values with either weight loss or weight regain after weight loss. Altogether these data suggest that in adolescence and at age above 55 years, in the obese and with weight change, organ and tissue masses differ in cellularity and/or their specific metabolic rates. Presently, direct assessment of specific organ and tissue metabolic rates in humans by either NMR spectroscopy or PET, together with detailed body composition analysis, has not been performed systematically.SummaryWe need to become more skilled in methods and models used for detailed body composition analysis together with detailed assessment of energy expenditure in humans.

• 出版日期2013-9