title: Serum leptin in obesity is related to gender and body fat topography but does not predict successful weight loss.
abstract: OBJECTIVE
  Leptin is the product of the ob gene shown to regulate body fat and appetite in mice. It is produced by human adipose tissue also, but its physiological functions in man are poorly known.
  
  
  METHODS
  We studied serum leptin concentrations in ten obese men and 35 obese women (age and body mass index 42 +/- 7 years and 35.1 +/- 3.6 kg/m2 respectively) before (baseline) and at 17 and 57 weeks during weight loss of 10.9% of the initial weight.
  
  
  RESULTS
  Serum leptin concentrations at baseline were 55% higher in women than in men (after adjustment for age and body fat mass, P = 0.002) and remained so during the follow-up. At baseline, serum leptin correlated with fat mass (r = 0.60, P < 0.001) estimated by bioelectrical impedance, and the changes in leptin concentrations from baseline to week 17 correlated with the changes in fat mass (r = 0.73, P < 0.001), but baseline leptin levels were not predictive of the successful weight loss. Leptin concentrations correlated with hip circumference (r = 0.49, P < 0.001 at baseline adjusted for age and sex), but the correlation with waist circumference became evident only during the weight loss (at week 57, r = 0.63, P < 0.001).
  
  
  CONCLUSIONS
  Serum leptin concentrations are higher in obese women than in obese men before and during weight loss, but the topography of fat tissue influences serum leptin concentrations. Serum leptin concentrations do not predict the response to weight reduction.
authors.affiliation: Department of Clinical Nutrition, University of Kuopio, Finland.
authors.forename: L K
authors.initials: LK
authors.lastname: Niskanen
authors.forename: S
authors.initials: S
authors.lastname: Haffner
authors.forename: L J
authors.initials: LJ
authors.lastname: Karhunen
authors.forename: A K
authors.initials: AK
authors.lastname: Turpeinen
authors.forename: H
authors.initials: H
authors.lastname: Miettinen
authors.forename: M I
authors.initials: MI
authors.lastname: Uusitupa
mesh_terms: D000273:Adipose Tissue; D000328:Adult; D001823:Body Composition; D001824:Body Constitution; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000628:therapy; D011506:Proteins / Q000378:metabolism*; D012727:Sex Characteristics; D015431:Weight Loss
chemical_list: D007328:Insulin; D020738:Leptin; D011506:Proteins