title: Reversal of the sex difference in plasma leptin levels in obese children with impaired glucose tolerance.
abstract: BACKGROUND
  Basal leptin level has been demonstrated to correlate positively with many indices of obesity, as well as insulin resistance. However, to date, little is known about regulation of leptin in obese children with incipient glucose metabolic disorders.
  
  
  OBJECTIVE
  The aim of this study was to define the precise influence of the glucose tolerance status on plasma leptin in obese boys and girls separately.
  
  
  METHODS
  70 obese children with impaired glucose tolerance (IGT) and well-matched 70 normal glucose-tolerant (NGT) subjects were examined. Fasting and 2-h post glucose load plasma glucose and insulin levels as well as fasting leptin levels were determined, apart from anthropometric measurements.
  
  
  RESULTS
  Leptin levels were significantly lower in girls with IGT compared to NGT girl (17.7+/-6.5 microg/L vs. 23.1+/-7.7 microg/L; p<.001). No such difference was observed in boys. In a multiple regression analysis adjusting for age and adiposity, in the female group plasma glucose and insulin levels 2-h after glucose load were the best predictors of fasting plasma leptin (r=-0.49, p<.005 and r=0.34, p<.05; respectively). In boys, plasma insulin level 2-h after glucose load was the independent determinant of leptin (r=0.36, p<.05).
  
  
  CONCLUSIONS
  The differences between regulation of leptin synthesis in girls and boys with simple obesity were found. The stimulatory effect of insulin on leptin synthesis was greater in girls with normoglycemia than in girls with impaired glucose tolerance.
authors.affiliation: Independent Laboratory of Propaedeutics of Children's Diseases, Pomeranian Medical University, Szczecin, Poland. propedeutyka1@wp.pl
authors.forename: Barbara
authors.initials: B
authors.lastname: Garanty-Bogacka
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Syrenicz
authors.forename: Anhelli
authors.initials: A
authors.lastname: Syrenicz
authors.forename: Aneta
authors.initials: A
authors.lastname: Gebala
authors.forename: Mieczysław
authors.initials: M
authors.lastname: Walczak
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000293:Adolescent; D002648:Child; D005260:Female; D018149:Glucose Intolerance / Q000097:blood* / Q000150:complications*; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D009765:Obesity / Q000150:complications* / Q000378:metabolism*; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012737:Sex Factors
chemical_list: D020738:Leptin