Plasma Copeptin in Response to Oral Urea in Healthy Adults and Patients With Polyuria-polydipsia Syndrome

Healthy volunteers Inclusion Criteria: * Age ≥18 years * Healthy with no medication except hormonal contraception Exclusion Criteria: * Participation in a trial with investigational drugs within 30 days * Evidence of disordered drinking habits and diuresis defined as polyuria \>50ml/kg body weight/24h and polydipsia \>3l /24h * Known allergy towards components of the study drink * Pregnancy and breastfeeding * Intention to become pregnant during the study * Evidence of acute illness Patients Inclusion Criteria: * Age ≥ 18 years * Documented PP or AVP-D based on accepted diagnostic criteria, i.e., water deprivation test, hypertonic saline infusion test or arginine infusion test. Accordingly, patients must have evidence of disordered drinking habits and diuresis defined as polyuria \>50ml/kg body weight/24h and polydipsia \>3l /24h or must be on regular daily desmopressin medication Exclusion Criteria: * Participation in a trial with investigational drugs within 30 days * Known allergy towards components of the study drink * Pregnancy and breastfeeding * Evidence of acute illness