title: Different thermic effects of leptin in adolescent females with varying body fat content.
abstract: OBJECTIVE
  Investigating the effect of leptin on energy expenditure in undernutrition might lead to a better understanding of the role of leptin in regulating body weight in humans.
  
  
  METHODS
  73 underweight female adolescents with anorexia nervosa (AN) were compared with 23 healthy normal weight (nwC), and 9 overweight girls (OW); 37 AN were followed during 7 months of weight recovery. Resting energy expenditure (REE, by indirect calorimetry), body composition (fat mass, FM; lean tissue mass, LTM; by Dual-Energy X-Ray Absorptiometry) and plasma hormones of leptin and 3,5,3'-Triiodothyronine (T(3)) were measured.
  
  
  RESULTS
  In underweight, leptin, T(3) and REE adjusted for lean tissue mass (REE(LTM)) were decreased; in OW, FM and leptin were increased at unchanged T(3) and REE(LTM). There was a significant positive relation between FM and leptin at low and normal (AN, r(2) = 0.26; nwC, r(2) = 0.51, p < 0.001), but not at high adiposity. Leptin and REE(LTM) were positively associated in underweight (r(2) = 0.14, p = 0.001) but not in normal or overweight subjects. T(3) was linearly related to REE(LTM) over the whole range of adiposity (r(2) = 0.42, p < 0.001). With weight gain in AN (5.0 ± 3.5 kg) the relationship between leptin and REE(LTM) changed toward the conditions seen in normal weight controls.
  
  
  CONCLUSIONS
  At low adiposity the interrelated fall of leptin and REE reflect an adaptive mechanism to preserve body weight. High leptin production associated with excessive adiposity was without effect on metabolic adaptation.
authors.affiliation: Department of Adolescent Medicine, The Children's Hospital at Westmead, University of Sydney, Australia. verena.haas@charite.de
authors.forename: Verena K
authors.initials: VK
authors.lastname: Haas
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Gaskin
authors.forename: Michael R
authors.initials: MR
authors.lastname: Kohn
authors.forename: Simon D
authors.initials: SD
authors.lastname: Clarke
authors.forename: Manfred J
authors.initials: MJ
authors.lastname: Müller
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism*; D050154:Adiposity; D000293:Adolescent; D000856:Anorexia Nervosa / Q000378:metabolism; D001823:Body Composition; D015992:Body Mass Index; D002153:Calorimetry, Indirect; D016022:Case-Control Studies; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood* / Q000378:metabolism; D016014:Linear Models; D050177:Overweight / Q000378:metabolism*; D012146:Rest; D013851:Thinness / Q000378:metabolism*; D014284:Triiodothyronine / Q000097:blood / Q000378:metabolism; D015430:Weight Gain
chemical_list: D020738:Leptin; D014284:Triiodothyronine