Ghrelin and leptin levels in obese adolescents. Relationship with body fat and insulin resistance.
OBJECTIVE
Ghrelin and leptin levels are influenced by body fat (BF%), pubertal stage and possibly insulin resistance (IR). The aim of our study was: 1) To compare fasting ghrelin and leptin levels between obese and non-obese, adolescents, 2) to investigate possible correlations of these hormones with BF %, as well as IR.


METHODS
Twenty obese insulin resistant (IR) adolescents, twenty obese non IR (NIR) and fifteen healthy non-obese, age-matched adolescents were studied. In all participants, height, weight, body mass index (BMI) and BF % were measured. Fasting glucose, insulin, ghrelin and leptin levels were determined. IR was assessed using HOMA-IR index.


RESULTS
BMI, BF %, insulin and HOMA-IR values were positively correlated with leptin and negatively with ghrelin levels. A negative correlation between circulating leptin and ghrelin levels was found. A suggestive positive correlation between leptin levels and BF %, independent of BMI, was also observed (P=0.075). Ghrelin levels were significantly correlated with insulin levels and HOMA-IR, independent of BMI (P=0.077).


CONCLUSIONS
Obesity and IR may play an important role in the release of ghrelin as well as in the negative correlation between ghrelin and leptin.
Stylianou
Charilaos
C
4th Department of Pediatrics, Medical School, Aristotle University of Thessaloniki, Greece.
Galli-Tsinopoulou
Assimina
A
Farmakiotis
Dimitrios
D
Rousso
Israel
I
Karamouzis
Michael
M
Koliakos
George
G
Nousia-Arvanitakis
Sanda
S
D000273:Adipose Tissue; D000293:Adolescent; D001786:Blood Glucose / Q000032:analysis; D001827:Body Height; D015992:Body Mass Index; D002648:Child; D005215:Fasting; D005260:Female; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D020738:Leptin / Q000097:blood*; D008297:Male; D009765:Obesity / Q000097:blood*
D001786:Blood Glucose; D054439:Ghrelin; D007328:Insulin; D020738:Leptin