Investigating the effects of mannitol on copeptin levels in healthy adults and patients with polyuria-polydipsia syndrome

Mannitol-induced Release of Copeptin in Healthy Adults and Patients With Polyuria-Polydipsia Syndrome: a Double-blind, Randomized Crossover Proof-of-concept and Open-label Single Arm Pilot Study (MARS Study)

Not applicable Interventional University Hospital, Basel, Switzerland · NCT06542198

This study is testing if mannitol can help increase copeptin levels in healthy adults and patients with polyuria-polydipsia syndrome to see if it could be a better option for diagnosing these conditions.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment42 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity Hospital, Basel, Switzerland Academic / other
Locations1 site (Basel)
Trial IDNCT06542198 on ClinicalTrials.gov

What this trial studies

This study aims to explore whether mannitol infusion can stimulate the release of copeptin in both healthy adults and patients diagnosed with polyuria-polydipsia syndrome, which includes arginine vasopressin deficiency and primary polydipsia. The research is divided into two parts: the first part is a double-blind, randomized cross-over proof-of-concept study in healthy individuals, while the second part is an open-label pilot study in patients with diagnosed conditions. The goal is to determine if mannitol can serve as a viable alternative to the current hypertonic saline infusion method for diagnosing these conditions.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with diagnosed primary polydipsia or arginine vasopressin deficiency.

Not a fit: Patients with uncontrolled diabetes mellitus, urinary tract obstruction, or those with disordered drinking habits may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a less invasive and more comfortable diagnostic method for patients with polyuria-polydipsia syndrome.

How similar studies have performed: While mannitol has been shown to stimulate AVP release, this specific approach to measuring copeptin levels after mannitol stimulation has not been previously tested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Part 1: Proof of Concept in Healthy adults

* Age ≥ 18 years
* Healthy with no medication except hormonal contraception

Part 2: Pilot Study in Patients with primary polydipsia (PP) or arginine vasopressin deficiency (AVP-D)

* Age ≥ 18 years
* Evidence of polyuria \> 40-50 ml/kg body weight per 24 hours and polydipsia \> 3 Liter per 24 hours or regular desmopressin medication corresponding to a diagnosis of PP or AVP-D

Exclusion Criteria:

Part 1: Proof of Concept in Healthy adults

* Participation in a trial with investigational drugs within 30 days
* Evidence of disordered drinking habits and diuresis defined as polyuria \> 40-50 ml/kg body weight per 24 hours and polydipsia \> 3 Liter per 24 hours.
* Estimated Glomerular Filtration Rate (eGFR) \< 60 ml/min/1,73 m2
* Glucose \> 11.1 mmol/L corresponding to the diagnosis of an uncontrolled diabetes mellitus
* History of urinary tract obstruction
* Problems with urination
* Pregnancy or breastfeeding
* Multiple allergies (≥ 3)
* Evidence of acute illness

Part 2: Pilot Study in Patients with PP or AVP-D

* Participation in a trial with investigational drugs within 30 days
* Pregnancy or breastfeeding
* Evidence of acute illness
* eGFR \< 60 ml/min/1,73 m2
* Glucose \> 11.1 mmol/L corresponding to the diagnosis of uncontrolled diabetes mellitus
* History of urinary tract obstruction
* Problems with urination
* Therapy with diuretics
* Multiple allergies (≥ 3)

Where this trial is running

Basel

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Polyuria-polydipsia SyndromeArginine Vasopressin DeficiencyPrimary PolydipsiaHypertonic saline infusionMannitolCopeptin
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.