Reversal of the sex difference in plasma leptin levels in obese children with impaired glucose tolerance.
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.
Garanty-Bogacka
Barbara
B
Independent Laboratory of Propaedeutics of Children's Diseases, Pomeranian Medical University, Szczecin, Poland. propedeutyka1@wp.pl
Syrenicz
Małgorzata
M
Syrenicz
Anhelli
A
Gebala
Aneta
A
Walczak
Mieczysław
M
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
D020738:Leptin