Insulin/C-peptide response to intravenous glucagon. A dose-response study in normal and non-insulin-dependent diabetic subjects.
The C-peptide and insulin secretory responses to increasing doses of iv glucagon (1, 2, 5, 10 micrograms/kg body weight and 1 mg (only diabetics] were investigated in six lean non-insulin-dependent diabetic patients and six normal subjects, matched for body weight and fasting blood glucose concentrations. A well defined relationship between glucagon dose and the C-peptide/insulin response was observed in both groups. The course of the dose-response curves was significantly different in diabetics. The maximal obtainable C-peptide response (E-max) was reduced to 53% of the response in normal subjects (P = 0.037), and the insulin response was reduced to 52% (P = 0.014). E-max was reached in diabetics with only 10 micrograms/kg of glucagon, whereas higher doses seem to be needed in the control group. However, the glucagon dose causing 50% of E-max (ED50) was not significantly higher. Thus, the widely accepted use of 1 mg of glucagon to test residual beta cell function secures a maximal response of both insulin and C-peptide in non-insulin-dependent diabetic subjects. In addition, our data support the theory that beta cell deficiency is a basic feature of non-insulin-dependent diabetes.
Snorgaard
O
O
Department of Endocrinology, Frederiksberg Hospital, Copenhagen, Denmark.
Hasselstrøm
K
K
Lumholtz
I B
IB
Thorsteinsson
B
B
Siersbaek-Nielsen
K
K
D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005934:Glucagon / Q000008:administration & dosage*; D006801:Humans; D007275:Injections, Intravenous; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000503:physiopathology; D008297:Male
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D005934:Glucagon