Copeptin After Arginine Infusion in Polyuria-Polydipsia Syndrome

Copeptin After Arginine Infusion for the Differential Diagnosis of the Polyuria-Polydipsia Syndrome ''The CARGO-Study''

the purpose of the study is to investigate whether arginine infusion is a new tool to differentiate patients with diabetes insipidus, primary polydipsia and healthy subjects.

Inclusion Criteria:

1. Age over 18 years
2. No medication except hormonal contraception

Exclusion Criteria:

1. Evidence of any acute illness
2. Subjects refusing or unable to give written informed consent
3. Pregnancy
4. Any evidence of disordered drinking habits and diuresis