title: Relation of leptin pulse dynamics to fat distribution in HIV-infected patients.
abstract: BACKGROUND
  HIV-infected patients are affected by changes in fat distribution, ie, significant losses of subcutaneous fat in association with metabolic abnormalities.
  
  
  OBJECTIVE
  The objective was to investigate the relation between leptin secretion and subcutaneous fat loss in HIV-infected patients.
  
  
  METHODS
  We investigated leptin pulse dynamics, measured every 20 min overnight from 2000 to 0800 in 41 HIV-infected patients with a mean (+/-SEM) age of 42.7 +/- 1.1 y and body mass index (in kg/m(2)) of 24.7 +/- 0.4 and in 20 healthy control subjects (age: 42.8 +/- 1.8 y; body mass index: 24.6 +/- 0.5). Leptin pulse variables were compared with total body fat, abdominal subcutaneous fat, and abdominal visceral fat in univariate and multivariate regression analyses.
  
  
  RESULTS
  The number of leptin pulses was not significantly different between the HIV-infected and control subjects. Subcutaneous fat correlated significantly with mean leptin secretion (r = 0.72, P <0.0001), leptin pulse amplitude (r = 0.62, P <0.0001), and leptin nadir (r = 0.62, P <0.0001) in the HIV-infected patients. In stepwise regression modeling, subcutaneous fat (P <0.0001), but not visceral fat, was significantly associated with leptin secretion (overall R(2) for the model = 0.57, P <0.0001) in the HIV-infected patients. For each 1-cm(2) decrease in abdominal subcutaneous fat area, leptin decreased by 0.044 ng/mL when visceral fat was controlled for. Subcutaneous fat was also significantly related to leptin in the control subjects.
  
  
  CONCLUSIONS
  This is the first study to investigate the relation between fat distribution and leptin pulse dynamics in HIV-infected patients. There was a significant reduction in leptin secretion with subcutaneous fat loss in this population.
authors.affiliation: Massachusetts General Hospital Program in Nutritional Metabolism and the Neuroendocrine Unit, Harvard Medical School, Boston 02114, USA.
authors.forename: Polyxeni
authors.initials: P
authors.lastname: Koutkia
authors.forename: Bridget
authors.initials: B
authors.lastname: Canavan
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Breu
authors.forename: Michael L
authors.initials: ML
authors.lastname: Johnson
authors.forename: Alex
authors.initials: A
authors.lastname: Depaoli
authors.forename: Steven K
authors.initials: SK
authors.lastname: Grinspoon
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001823:Body Composition; D016022:Case-Control Studies; D015658:HIV Infections / Q000378:metabolism*; D006801:Humans; D020738:Leptin / Q000378:metabolism*; D012044:Regression Analysis
chemical_list: D020738:Leptin