The current study has two aims:

1. to test the hypothesis that a single dose of lixisenatide can be used as a growth hormone stimulation test;
2. to test if the growth hormone-stimulating effect is mediated by changes in blood glucose.

The secondary objective of the study is to monitor the effect of lixisenatide on other pituitary hormones and physiological parameters (blood glucose, blood pressure, heart rate, nausea).

The randomized, blinded, placebo-controlled clinical trial is conducted on 5 healthy volunteers and 5 patients with type 1 diabetes.

All study subjects receive once a placebo and once 10 micrograms of lixisenatide.

The order of administration of study medication is decided on randomization. The placebo and lixisenatide are administered at least 2 days apart.

Blood samples are taken 30 minutes and immediately before study medication administration and 30, 60, 90, 120, and 150 minutes after study medication administration,.

The primary endpoint is the peak value of growth hormone measured during the 2,5 hours after study medication administration.

Inclusion Criteria:

1. Healthy volunteers:

   • male sex
   • age 18-60 years
   • body weight > 65 kg

2. Patients with type 1 diabetes:

   • type 1 diabetes
   • male sex
   • age 18-60 years
   • body weight > 65 kg
   • c-peptide in fasting blood sample <0,1 nmol/l
   • HbA1c < 8,5%

Exclusion Criteria:

1. Healthy volunteers:

   • use of aldosterone antagonist
   • use of glucocorticosteroid
   • use of other medication that potentially significantly affects pituitary function.

2. Patients with type 1 diabetes:

   • use of aldosterone antagonist
   • use of glucocorticosteroid
   • use of other medication that potentially significantly affects pituitary function.
   • The patient is excluded from the study if a significant change in blood glucose occurs in the study center.