title: Hyperleptinemia is more closely associated with adipose cell hypertrophy than with adipose tissue hyperplasia.
abstract: OBJECTIVE
  To investigate the relationships of fat cell weight (FCW) as well as of estimated total adipose cell number to fasting plasma leptin concentration.
  
  
  METHODS
  Cross-sectional correlational study.
  
  
  METHODS
  A sample of 63 men (mean age+/-s.d.: 36+/-4 y) and 42 premenopausal women (35+/-5 y).
  
  
  METHODS
  Adipose tissue (AT) biopsies were obtained in order to determine FCW as well as estimated adipose cell number. Fasting plasma leptin and insulin concentrations as well as various fatness and body fat distribution variables (underwater weighing and computed tomography) were also measured.
  
  
  RESULTS
  In both genders, mean FCW as well as the estimated adipose cell number were significantly correlated with body fatness and AT distribution variables (0.41</=r</=0.84). Larger abdominal (P<0.005) and femoral (P<0.0001) FCW were found in women than in men. This gender difference in adipose cell size was associated with increased leptin concentrations in women compared with men. In both genders, increased abdominal FCW was associated with higher plasma leptin concentrations (men: r=0.38, P<0.005 and women: r=0.55, P<0.0001). However, the association between femoral FCW and leptinemia was only significant in women (r=0.45, P<0.005). Contrary to women, plasma leptin concentrations were associated with estimated adipose cell number in men (r=0.59, P<0.0001). Multiple regression analyses revealed that gender (43.3%), mean FCW (16.2%) and the estimated adipose cell number (10.1%) were significant predictors of fasting leptinemia.
  
  
  CONCLUSIONS
  Results of the present study indicate that in men and women, adipose cell hypertrophy is associated with increased plasma leptin concentrations. This finding provides further support to the observation that adipose tissue leptin secretion may be regulated, at least to a certain extent, by adipocyte size. Thus, the present study suggests that the higher plasma leptin concentrations found in women than in men could be partly explained by the well documented gender difference in adipose cell size and number.
authors.affiliation: Lipid Research Center, CHUQ Research Center, CHUL Pavilion, Sainte-Foy (Québec) Canada.
authors.forename: C
authors.initials: C
authors.lastname: Couillard
authors.forename: P
authors.initials: P
authors.lastname: Mauriège
authors.forename: P
authors.initials: P
authors.lastname: Imbeault
authors.forename: D
authors.initials: D
authors.lastname: Prud'homme
authors.forename: A
authors.initials: A
authors.lastname: Nadeau
authors.forename: A
authors.initials: A
authors.lastname: Tremblay
authors.forename: C
authors.initials: C
authors.lastname: Bouchard
authors.forename: J P
authors.initials: JP
authors.lastname: Després
mesh_terms: D017667:Adipocytes / Q000473:pathology*; D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D001706:Biopsy; D001823:Body Composition; D002452:Cell Count; D048429:Cell Size; D003430:Cross-Sectional Studies; D005215:Fasting; D005260:Female; D006801:Humans; D006965:Hyperplasia; D006984:Hypertrophy; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000032:analysis*; D008297:Male; D012044:Regression Analysis
chemical_list: D007328:Insulin; D020738:Leptin