Influence of Glucagon Inhibition in Relation to the Anti-Diabetic Effect of Glucagon-Like Peptide-1 (GLP-1) in Patients With Type 2 Diabetes Mellitus

Condition(s) targeted: Type 2 Diabetes Mellitus

Intervention: Infusion of native hormones from the pancreas and gut (GLP-1) (Other)

Phase: N/A

Status: Active, not recruiting

Sponsored by: University Hospital, Gentofte, Copenhagen

Incretinbased treatment of patients with type 2 diabetes mellitus (T2DM) has increasing interest. The incretin glucagon-like peptide-1 (GLP-1) stimulates beta-cells to increased

secretion and production of insulin. Glucose sensitivity is enhanced, apoptosis inhibited -

progression in disease is potentially stopped. The alpha-cell is also influenced by GLP-1 as infusion lowers plasmaglucose (PG) levels in patients with type 1 diabetes mellitus (T1DM) (C-peptide negative) by inhibition of glucagon and thereby decreased hepatic glucoseproduction (HGP). Further Vilsboll et al has proved normalization of the glacgonostatic effect of glucose in patients with T2DM. As an attempt to elucidate glucose-intolerance in patients with T2DM further Knop et al investigated the glucagonresponse to both oral glucose tolerance test (OGTT) and a following iso-glycemic clamp. He saw a sufficient suppression of glucagon when glucose was introduced intravenously but the suppression of glucagon was attenuated and delayed when glucose was given orally.

The aim of this study is to elucidate the glucose intolerance further. Due to the complex interactions and mutual feed-back regulation between the pancreatic hormones and the PG level this protocol includes five days. All days include a euglycemic-clamp, patients with T2DM (n=10) are clamped at their fasting PG as are healthy control subjects (n=10). During the clamp either GLP-1 alone; GLP-1 in combination with somatostatin, insulin and glucagon; or somatostatin, insulin and glucagon are infused and blood samples are drawn.

The design of the study makes it possible to isolate the effect of each hormone. Further we will be able to enlighten the effect of GLP-1 on the increase in glucose turn-over it induces.

The essential part in this design will be hormone concentrations and the response parameter the amount of glucose (AUC) it takes to create the euglycemic-clamp.

Official title: Influence of Glucagon Inhibition in Relation to the Anti-Diabetic Effect of GLP-1 in Patients With Type 2 Diabetes Mellitus.

Study design: Basic Science, Randomized, Single Blind (Subject), Active Control, Single Group Assignment

Primary outcome: Glucose turn-over

Secondary outcome: The inhibitory effect of GLP-1 on glucagon, and the role of this in its anti-diabetic potential, measured by looking at glucose turn-over.

Minimum age: 18 Years. Maximum age: 70 Years. Gender(s): Both.

Criteria:

Inclusion Criteria:

- Type 2 Diabetes Mellitus according to criteria from WHO

- Normal hepatic and kidney function

- No overt diabetic complications

- Treatment with insulin or glitazones

- Informed consent

Exclusion Criteria:

- BMI < 23

- BMI > 35

- HbA1c > 10%

- Pregnancy

Starting date: March 2008
Ending date: December 2008
Last updated: April 4, 2008