Growth hormone response to GHRH + GHRP-6 in type 2 diabetes during euglycemic and hyperglycemic clamp.
The aim of this study was to investigate the effect of two different glucose levels on GH response to the combined administration of GHRH+GHRP-6 in patients with type 2 diabetes. GH response to i.v. bolus of GHRH+GHRP-6 (100 mcg, each) was measured in 12 male patients with type 2 diabetes (mean age: 53.9+/-1.59 years; BMI: 25.58+/-0.39 kg/m(2); mean HbA(1c): 8.7+/-0.42%), during a euglycemic (mean glucose: 4.92+/-0.08 mmol) hyperinsulinemic clamp (insulin infusion rate of 100 mU/kg/h) and a hyperglycemic clamp (mean glucose: 12.19+/-0.11 mmol/l). There was no difference in basal GH levels between the hyperglycemic and euglycemic clamps (2.9+/-0.99 mU/l versus 1.48+/-0.44 mU/l; P>0.05). Peak GH response to GHRH+GHRP-6 during the hyperglycemic clamp was lower than in the englycemic clamp (112.45+/-14.45 mU/l versus 151.06+/-16.87 mU/l; P<0.05). Area under the GH curve was lower in the hyperglycemic than in the euglycemic clamp (6974.49+/-1001.95 mU/l/min versus 9560.75+/-1140.65 mU/l/min; P<0.05). It is concluded that hyperglycemia significantly reduces GH response to combined administration of GHRH+GHRP-6 in normal weight patients with type 2 diabetes. It is suggested that ambient glucose levels should be taken into account during interpretation of GH response to combined administration of GHRH+GHRP-6 in patients with type 2 diabetes.
Micic
Dragan
D
Institute of Endocrinology, Diabetes and Diseases of Metabolism, Clinical Center of Serbia, Dr. Subotica 13, 11000, Belgrade, Serbia and Montenegro. micicd@eunet.yu
Kendereski
Aleksandra
A
Sumarac-Dumanovic
Mirjana
M
Cvijovic
Goran
G
Popovic
Vera
V
Dieguez
Carlos
C
Casanueva
Felipe
F
D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism*; D004338:Drug Combinations; D015309:Glucose Clamp Technique; D013007:Growth Hormone-Releasing Hormone / Q000008:administration & dosage*; D019382:Human Growth Hormone / Q000097:blood / Q000378:metabolism*; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism; D006946:Hyperinsulinism / Q000378:metabolism; D007275:Injections, Intravenous; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D009842:Oligopeptides / Q000008:administration & dosage*; D015203:Reproducibility of Results
D004338:Drug Combinations; D007328:Insulin; D009842:Oligopeptides; D019382:Human Growth Hormone; C041048:growth hormone releasing hexapeptide; D013007:Growth Hormone-Releasing Hormone