Not Yet RecruitingNot Applicable

Arginin-stimulated Copeptin in Polyuria-polydipsia Syndrome in Children

France155 participantsStarted 2025-03

Plain-language summary

The exploration of polyuro-polydipsia syndrome (PPS) with hypotonic polyuria should distinguished, primary polydipsia (PP) due to excessive water intake, central diabetes insipidus (CDI) related to insufficient secretion of antidiuretic hormone (AVP), and nephrogenic diabetes insipidus (NDI) related to AVP insensitivity. The determination of plasma AVP is not relevant (unstable concentration, short in vitro half-life, long technical time and large blood sample). The differential diagnosis is currently based on a water deprivation test (WDT), an indirect reflection of AVP action, requiring more than 6 hours of hospitalization with risk of dehydration and low accuracy. Copeptin represents a new biomarker, direct mirror of AVP release with remarkable characteristics (stable, rapid determination, small blood volume). Copeptin has become a diagnostic tool in adult PPS and eliminated WDT in the diagnostic process. In children, basal copeptin values help for NDI and to exclude CDI (basal copeptin threshold \> 30 and \> 3.53 pmol/l (Se 100%, Sp 87.4%), respectively). Below 3.53 pmol/l, basal copeptin performance was inadequate to discriminate PP and CDI, highlighting the relevance of the stimulated copeptin study to improve this strategy. The arginine stimulation test is widely used as a simple, short duration (2 hours) and well tolerated tool to diagnose growth hormone deficiency in pediatrics. The performance of this test for copeptin stimulation was studied in adults with PPS with a high diagnostic accuracy. The aim of the study is identify the best discriminant threshold of the arginine stimulation test in the uncertain diagnosis (basal copeptin \<30 pmol/l) in the polyuro-polydipsic syndrome in children. Then evaluate the discriminative capacities of the arginine stimulation test between the primary polydipsia and central insipid diabetes in the polyuro-polydipsic syndrome in children. And finally evaluate the cost-effectiveness of a new decisional algorithm for the differential diagnosis of PPS in children and evaluate the impact of infusion volume on copeptin secretion using the protidemia copeptin ratio.

Who can participate

Age range

2 Years – 18 Years

Sex

ALL

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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Children aged 2 to 18 years with polyuro-polydipsia syndrome (defined as hypotonic diuresis \> 50 mL/kg/day in pediatric age or 30 mL/kg/day in late puberty (Tanner 5)) presenting for differential diagnosis between PP and DIC * Basal copeptin of less than 30 pmol/l * Agreeing to participate in the study * Whose two parents' consent to have their child participate in the study. Exclusion Criteria: * Diabetes mellitus * Unbalanced dysthyroidism * Corticotropic deficiency * Ionic disorders (dysnatremia \< 135 or \> 145 mmol/l, dyskalemia \< 3 or \> 5 mmol/l, corrected dyscalcemia \< 2.2 or \> 2.6 mmol/L) * Moderate to severe clinical dehydration (recent weight loss \> 5% of body weight, clinical or biological signs of dehydration) requiring immediate therapeutic management * Renal failure with GFR \< 60 mL/min/1.73 m2 * Uropathy * Tumor syndrome (except hypothalamo-pituitary tumor) * Intracranial hypertension * ROHHAD syndrome * Fever or biological inflammatory syndrome with CRP \> 5 mg/L * Hepatic insufficiency * Contraindication to MRI * Contraindication to progressive water intake restrictions * History of contraindication to arginine * Positive test for Pregnancy * Lack of authorization by both parents or legal representatives

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

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Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Measurement of arginine-stimulated copeptine level

Timeframe: Different time points of argenine stimulates copeptine level will be measured at 45 minutes, 60 minutes, 90 minutes and 120 minutes

Trial details

NCT IDNCT06604975

SponsorAssistance Publique Hopitaux De Marseille

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2028-05

Contact for this trial

Rachel REYNAUD

0491388040 Rachel.REYNAUD@ap-hm.fr

View on ClinicalTrials.gov More Primary Polydipsia trials