title: Influence of segmental body composition and adiposity hormones on resting metabolic rate and substrate utilization in overweight and obese adults.
abstract: OBJECTIVE
  Low resting metabolic rate (RMR) and high carbohydrate reliance at rest are associated with weight gain, but are highly variable in obese individuals. This study determined the relationship of total and segmental body composition and adiposity hormones with RMR and respiratory exchange ratio (RER) in overweight and obese adults.
  
  
  METHODS
  In 49 men (n = 23) and premenopausal women (n = 26) [mean ± SD; age = 35.0 ± 8.9 years; body mass index (BMI) = 33.6 ± 5.2 kg·m-2; percent body fat (%fat) = 40.0 ± 8.0%], RMR and RER were evaluated using indirect calorimetry. Total and segmental body composition [fat mass (FM), percent fat (%fat), lean mass (LM), visceral adipose tissue (VAT)] were estimated using dual-energy X-ray absorptiometry. Fasted blood and saliva samples were analyzed for insulin, leptin, estradiol, and cortisol.
  
  
  RESULTS
  In men (M) and women (W), RMR significantly correlated (p < 0.05) with FM (M: R = 0.535; W: R = 0.784) and LM (M: R = 0.645; W: R = 0.867). Of the segmental measures, trunk LM (M: R = 0.593; W: R = 0.879; p < 0.05) and leg LM (M: R = 0.664; W: R = 0.821; p < 0.05) had the strongest correlations with RMR. In men, but not women, RER significantly correlated with FM (R = 0.449; p = 0.032), trunk FM (R = 0.501; p = 0.015), and VAT (R = 0.456; p = 0.029). In men, RMR positively correlated with cortisol (R = 0.430, p = 0.040) and estradiol (R = 0.649, p = 0.001) and RER positively correlated with insulin (R = 0.525, p = 0.010). In women, RMR positively correlated with insulin (R = 0.570, p = 0.006), but RER was not significantly correlated with hormones (p > 0.05).
  
  
  CONCLUSIONS
  Segmental evaluation of body composition, specifically in the lower extremities and abdomen, may be an effective and efficient way to evaluate metabolic status. Sex-specific evaluations are also imperative.
authors.affiliation: Applied Physiology Lab, Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB# 8700, Chapel Hill, NC, 27599-8700, USA.|Human Movement Science Curriculum, Department of Allied Health Science, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: K R
authors.initials: KR
authors.lastname: Hirsch
authors.affiliation: Applied Physiology Lab, Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB# 8700, Chapel Hill, NC, 27599-8700, USA. abbsmith@email.unc.edu.|Human Movement Science Curriculum, Department of Allied Health Science, University of North Carolina, Chapel Hill, NC, USA. abbsmith@email.unc.edu.
authors.forename: A E
authors.identifier: http://orcid.org/0000-0002-5405-304X
authors.initials: AE
authors.lastname: Smith-Ryan
authors.affiliation: Applied Physiology Lab, Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB# 8700, Chapel Hill, NC, 27599-8700, USA.|Human Movement Science Curriculum, Department of Allied Health Science, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: M N M
authors.initials: MNM
authors.lastname: Blue
authors.affiliation: Applied Physiology Lab, Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB# 8700, Chapel Hill, NC, 27599-8700, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Mock
authors.affiliation: Applied Physiology Lab, Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB# 8700, Chapel Hill, NC, 27599-8700, USA.|Human Movement Science Curriculum, Department of Allied Health Science, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: E T
authors.initials: ET
authors.lastname: Trexler
mesh_terms: D050154:Adiposity; D000328:Adult; D001481:Basal Metabolism; D001823:Body Composition; D015992:Body Mass Index; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D020738:Leptin / Q000378:metabolism*; D008297:Male; D009765:Obesity / Q000503:physiopathology*; D050177:Overweight / Q000503:physiopathology*
chemical_list: D007328:Insulin; D020738:Leptin
keywords: Insulin; Lean mass; Leptin; Metabolism; Sex; Visceral Fat