Glucose-dependent Insulinotropic Polypeptide - New Role as Blood Glucose Stabilizer?

Glucose-dependent Insulinotropic Polypeptide - New Role as Blood Glucose Stabilizer?

The purpose of this study is to determine whether glucose-dependent insulinotropic polypeptide (GIP) has a stabilizing function on the blood glucose

The aim of the study is to investigate the effect of GIP on the glucagon secretion during hyper-, eu- and hypoglycemia in healthy volunteers, patients with type 1 diabetes mellitus and patients with type 2 diabetes mellitus.

From this, we will evaluate GIP's role as blood sugar stabilizer.

Inclusion Criteria:

• Caucasians with T1DM (diagnosed according to WHO's criteria) without residual beta cell function (arginine test without increase in c-peptide) in treatment with long acting insulin OR
• Caucasians with non-insulin treated T2DM (diagnosed according to WHO's criteria) OR
• Caucasians without first degree relative with diabetes mellitus, with normal fasting plasma glucose and glucose tolerance along with negative islet and GAD-65 autoantibodies AND
• Normal hemoglobin
• Informed consent

Exclusion criteria:

• Unwillingness to participate or the wish to leave the present study
• HbA1c > 9 %
• Liver disease (ALAT or ASAT > 2 times normal value)
• Diabetic nephropathy (serum creatinin > 130 microM and/or albuminury)
• Proliferative diabetic retinopathy (anamnetic)
• Atherosclerotic heart disease or heart failure (NYHA group III and IV)
• Anemia
• Treatment with medicine which cannot be paused for 12 hours
• Pregnancy and/or breast feeding
• Fasting plasma glucose > 15 mM on the day of the experiment