Persistence of altered metabolic responses to beta-endorphin after normalization of body weight in human obesity.
The responses of plasma glucose, insulin, C-peptide and glucagon to an infusion of human beta-endorphin (0.5 mg/h) were studied in 10 formerly obese subjects who had lost 35 kg by dieting (body mass index less than 25) and compared with those of 10 normal-weight control (body mass index less than 25) and 10 obese (body mass index greater than 30) subjects. The fasting plasma concentrations of beta-endorphin were significantly higher in both the obese and the post-obese group than in the control group. In both obese and post-obese subjects, the infusion of beta-endorphin caused significant increases in peripheral plasma glucose, insulin, C-peptide and glucagon concentrations. In the control group, matched for age, sex and weight with the formerly obese group, there was no appreciable change in plasma insulin and C-peptide concentrations during the infusion of beta-endorphin, but the rise in plasma glucose was more sustained. Thus, 1. the increased plasma beta-endorphin concentrations found in human obesity are not corrected by normalization of body weight; and 2. formerly obese, normal-weight subjects behave as obese subjects in their metabolic and hormonal responses to beta-endorphin infusion. The alteration of the opioid system in human obesity may play some role in the predisposition to weight gain.
Giugliano
D
D
Chair of Diabetology, First Faculty of Medicine, University of Naples, Italy.
Cozzolino
D
D
Torella
R
R
Lefebvre
P J
PJ
Franchimont
P
P
D'Onofrio
F
F
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D002096:C-Peptide / Q000097:blood; D005260:Female; D005934:Glucagon / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007700:Kinetics; D008297:Male; D009765:Obesity / Q000097:blood*; D001615:beta-Endorphin / Q000097:blood / Q000494:pharmacology*
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D001615:beta-Endorphin; D005934:Glucagon