title: Effect of constitution on mass of individual organs and their association with metabolic rate in humans--a detailed view on allometric scaling.
abstract: Resting energy expenditure (REE)-power relationships result from multiple underlying factors including weight and height. In addition, detailed body composition, including fat free mass (FFM) and its components, skeletal muscle mass and internal organs with high metabolic rates (i.e. brain, heart, liver, kidneys), are major determinants of REE. Since the mass of individual organs scales to height as well as to weight (and, thus, to constitution), the variance in these associations may also add to the variance in REE. Here we address body composition (measured by magnetic resonance imaging) and REE (assessed by indirect calorimetry) in a group of 330 healthy volunteers differing with respect to age (17-78 years), sex (61% female) and BMI (15.9-47.8 kg/m(2)). Using three dimensional data interpolation we found that the inter-individual variance related to scaling of organ mass to height and weight and, thus, the constitution-related variances in either FFM (model 1) or kidneys, muscle, brain and liver (model 2) explained up to 43% of the inter-individual variance in REE. These data are the first evidence that constitution adds to the complexity of REE. Since organs scale differently as weight as well as height the "fit" of organ masses within constitution should be considered as a further trait.
authors.affiliation: Institut für Humanernährung und Lebensmittelkunde, Christian-Albrechts-Universität zu Kiel, Kiel, Germany. mmueller@nutrfoodsc.uni-kiel.de
authors.forename: Manfred J
authors.initials: MJ
authors.lastname: Müller
authors.forename: Dirk
authors.initials: D
authors.lastname: Langemann
authors.forename: Isabel
authors.initials: I
authors.lastname: Gehrke
authors.forename: Wiebke
authors.initials: W
authors.lastname: Later
authors.forename: Martin
authors.initials: M
authors.lastname: Heller
authors.forename: Claus C
authors.initials: CC
authors.lastname: Glüer
authors.forename: Steven B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: Anja
authors.initials: A
authors.lastname: Bosy-Westphal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000886:Anthropometry / Q000379:methods*; D001481:Basal Metabolism / Q000502:physiology*; D001824:Body Constitution / Q000502:physiology*; D001827:Body Height / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size / Q000502:physiology; D009928:Organ Specificity; D012044:Regression Analysis; D012146:Rest / Q000502:physiology; D055815:Young Adult