Scaling of adult regional body mass and body composition as a whole to height: Relevance to body shape and body mass index.

ABSTRACT: Adult body mass (MB) empirically scales as height (Ht) squared (MB ? Ht(2) ), but does regional body mass and body composition as a whole also scale as Ht(2) ? This question is relevant to a wide range of biological topics, including interpretation of body mass index (BMI).Dual-energy X-ray absorptiometry (DXA) was used to quantify regional body mass [head (MH), trunk, arms, and legs] and whole-body composition [fat, lean soft tissue (LST), and bone mineral content (BMC)] in non-Hispanic (NH) white, NH black, Mexican American, and Korean adults participating in the National Health and Nutrition Examination Survey (NHANES; n = 17,126) and Korean NHANES (n = 8,942). Regression models were developed to establish Ht scaling powers for each measured component with adjustments for age and adiposity.Exploratory analyses revealed a consistent scaling pattern across men and women of the four population groups: regional mass powers, head (?0.8-1) < arms and trunk (?1.8-2.3) < legs (?2.3-2.6); and body composition, LST (?2.0-2.3) < BMC (?2.1-2.4). Small sex and population differences in scaling powers were also observed. As body mass scaled uniformly across the eight sex and population groups as Ht(?2) , tall and short subjects differed in body shape (e.g., MH/MB ? Ht(-?1) ) and composition.Adult human body shape and relative composition are a function of body size as represented by stature, a finding that reveals a previously unrecognized phenotypic heterogeneity as defined by BMI. These observations provide new pathways for exploring mechanisms governing the interrelations between adult stature, body morphology, biomechanics, and metabolism.

SUBMITTER: Schuna JM 

PROVIDER: S-EPMC4638414 | biostudies-literature | 2015 May-Jun

REPOSITORIES: biostudies-literature