title: Plasma adiponectin levels are not associated with fat oxidation in humans.
abstract: OBJECTIVE
  To test the hypothesis that low adiponectin is associated with low fat oxidation in humans.
  
  
  METHODS
  We measured plasma adiponectin concentrations in 75 healthy, nondiabetic Pima Indians (age, 28 +/- 7 years; 55 men and 20 women; body fat, 29.7 +/- 7.5%) and 18 whites [(age, 33 +/- 8 years; 14 men and 4 women; body fat, 28.2 +/- 10.8% (means +/- SD)] whose body composition was measured by DXA and 24-hour energy expenditure (24-hour EE) by a respiratory chamber. Respiratory quotient (an estimate of whole-body carbohydrate/lipid oxidation rate) was calculated over 24 hours (24-hour RQ).
  
  
  RESULTS
  Before correlational analyses, waist-to-thigh ratio (WTR) and percentage of body fat (PFAT) were adjusted for age, sex, and race; 24-hour EE was adjusted for fat mass and fat-free mass, and 24-hour RQ were adjusted for energy balance. Plasma adiponectin concentrations were negatively correlated with WTR (r = -0.42, p < 0.0001) and PFAT (r = -0.46, p < 0.0001). There was no correlation between plasma adiponectin concentrations and 24-hour RQ, (r = 0.09, p = 0.36) before or after adjustment for PFAT (r = 0.001, p = 0.99, respectively, partial correlation), and no correlation was found between plasma adiponectin concentrations and 24-hour EE (r = -0.12, p = 0.27).
  
  
  CONCLUSIONS
  Our cross-sectional data do not suggest physiological concentrations of fasting plasma adiponectin play a role in the regulation of whole-body fat oxidation or energy expenditure in resting conditions. Whether administration of adiponectin to individuals with low levels of this hormone will increase their fat oxidation rates/energy expenditure remains to be established.
authors.affiliation: Clinical Diabetes and Nutrition Section, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona 85016, USA. nstefan@mail.nih.gov
authors.forename: Norbert
authors.initials: N
authors.lastname: Stefan
authors.forename: Barbora
authors.initials: B
authors.lastname: Vozarova
authors.forename: Tohru
authors.initials: T
authors.lastname: Funahashi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsuzawa
authors.forename: Eric
authors.initials: E
authors.lastname: Ravussin
authors.forename: Christian
authors.initials: C
authors.lastname: Weyer
authors.forename: P Antonio
authors.initials: PA
authors.lastname: Tataranni
mesh_terms: D015502:Absorptiometry, Photon; D052242:Adiponectin; D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition / Q000502:physiology; D002153:Calorimetry, Indirect; D015331:Cohort Studies; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007198:Indians, North American; D007328:Insulin / Q000097:blood / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D011506:Proteins / Q000378:metabolism*; D044465:White People
chemical_list: D052242:Adiponectin; D001786:Blood Glucose; D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins