Acute effects of acylated and unacylated ghrelin on total and high molecular weight adiponectin inmorbidly obese subjects.
BACKGROUND
Energy homeostasis and body weight are regulated by a highly complex network involving the brain, the digestive tract, and white adipose tissue (WAT). Knowledge about signaling pathways connecting digestive tract and WAT is limited. Gut hormone ghrelin and adipokine adiponectin are both decreased in obesity and they share a potent effect on insulin sensitivity: both adiponectin and the combination of acylated (AG) and unacylated ghrelin (UAG) improve insulin sensitivity.


OBJECTIVE
In the present study, we evaluated whether acute administration of UAG alone or combined with AG affects adiponectin concentrations.


METHODS
Eight morbidly obese non-diabetic subjects were treated with either UAG 200 μg, UAG 100 μg + AG 100 μg (Comb), or placebo in 3 episodes in a double blind randomized cross-over design. Study medication was administered as single iv bolus injections at 09:00 h after an overnight fast. High molecular weight (HMW) and total adiponectin, glucose, insulin, and total ghrelin and AG were measured up to 1 h after administration.


RESULTS
HMW and total adiponectin concentrations did not change after administration of either UAG or Comb, nor were they different from placebo. Insulin concentrations decreased significantly after acute administration of Comb, reaching a minimum at 20 min: 58.2 ± 3.9% of baseline.


CONCLUSIONS
Acute iv administration of UAG and the combination of UAG and AG in morbidly obese non-diabetic subjects without overt diabetes does not affect total or HMW adiponectin concentrations, neither directly nor indirectly by changing insulin concentrations.
Kiewiet
R M
RM
Division of Endocrinology, Department of Internal Medicine, Erasmus University Medical Centre, CA Rotterdam, The Netherlands. r.kiewiet@erasmusmc.nl
Hazell
M J
MJ
van Aken
M O
MO
van der Weerd
K
K
Visser
J A
JA
Themmen
A P N
AP
van der Lely
A J
AJ
D000215:Acylation; D052242:Adiponectin / Q000097:blood*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D054439:Ghrelin / Q000008:administration & dosage*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009767:Obesity, Morbid / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D011379:Prognosis
D052242:Adiponectin; D001786:Blood Glucose; D054439:Ghrelin; D007328:Insulin