Acute insulin infusion decreases plasma ghrelin levels in uncomplicated obesity.
BACKGROUND
Plasma ghrelin levels have been shown to decrease after insulin infusion in lean subjects. Nevertheless, the mechanism of the suggested inhibitory effect of insulin on ghrelin is still unclear and no data about the effect of acute insulin infusion on plasma ghrelin concentration in obese subjects are available.


OBJECTIVE
We sight to evaluate plasma ghrelin concentration during an hyperinsulinemic euglycemic clamp in uncomplicated obese subjects.


METHODS
35 uncomplicated obese subjects, body mass index (BMI) 43.3+/-10.1 kg/m(2), 33 women and 2 men, mean age 34.9+/-10, with a history of excess fat of at least 10 years underwent euglycemic hyperinsulinemic clamp. Blood samples for ghrelin were performed at baseline and steady state of euglycemic insulin clamp.


RESULTS
Ghrelin concentrations decreased over time to 10.6+/-15% (range 2-39%) of baseline, from a mean of 205.53+/-93.79 pg/ml to 179.03+/-70.43 pg/ml during the clamp (95% CI, 10.69 to 36.44, P<0.01). In a univariate linear regression analysis baseline plasma ghrelin levels were inversely correlated to BMI (r=-0.564, P=0.04). A linear positive trend between whole body glucose utilization (M(FFMkg) index) and ghrelin reduction during the clamp was found (chi(2) 3.05, p=0.05).


CONCLUSIONS
Our data seem to suggest that hyperinsulinemia during a euglycemic clamp is able to suppress plasma ghrelin concentrations in uncomplicated obesity. This effect appears to be positively related to insulin sensitivity.
Leonetti
Frida
F
Endocrinology, Department of Clinical Sciences, University "La Sapienza", Rome, Italy.
Iacobellis
Gianluca
G
Ribaudo
Maria Cristina
MC
Zappaterreno
Alessandra
A
Tiberti
Claudio
C
Iannucci
Concetta Valeria
CV
Vecci
Elio
E
Di Mario
Umberto
U
D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D054439:Ghrelin; D015309:Glucose Clamp Technique; D006801:Humans; D007328:Insulin / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D036361:Peptide Hormones / Q000097:blood*
D054439:Ghrelin; D007328:Insulin; D036361:Peptide Hormones