Not yet recruitingNAINTERVENTIONAL

Arginin-stimulated Copeptin in Polyuria-polydipsia Syndrome in Children

This study aims to find a better, quicker way to diagnose why children might be peeing a lot and feeling very thirsty. Currently, it can be tricky to tell the difference between drinking too much water, a problem with a hormone that controls water in the body (called Central Diabetes Insipidus), or kidneys that don't respond to that hormone (Nephrogenic Diabetes Insipidus). Standard tests can be long and uncomfortable. This research is testing a new blood test using a marker called copeptin, taken after giving a special amino acid drink (arginine). The goal is to see if this new approach can accurately identify the cause without needing the older, more difficult tests, making diagnosis easier for children and their families.

At a glance

Status

Not yet recruiting

Phase

Sponsor

Assistance Publique Hopitaux De Marseille

Enrolment target

155

Start

01 Mar 2025

Estimated completion

01 Jul 2028

Primary Polydipsia Central Diabetes Insipidus Nephrogenic Diabetes Insipidus

What is this study about?

Imagine your child is drinking a lot and needing to pee very frequently. This can be worrying, and doctors need to find out why. Sometimes, it's simply because a child drinks too much water (this is called Primary Polydipsia). Other times, it's due to a problem with how the body handles water, specifically with a hormone that tells your kidneys to hold onto water.

Currently, finding the exact reason can involve a test where your child has to go without water for several hours in a hospital, which can be difficult and isn't always accurate. This study is exploring a new, more straightforward blood test. It measures a substance called copeptin, which reflects how much of that important water-controlling hormone the body is making. Researchers are trying to see if doing this blood test after giving a special amino acid drink (arginine) can quickly and accurately tell the difference between the various reasons for excessive thirst and peeing, especially when other copeptin tests aren't clear.

The main goal is to improve how doctors diagnose these conditions in children. If successful, this new test could mean less time in hospital, fewer uncomfortable procedures, and a quicker path to getting the right treatment. This study is important because it could lead to a simpler, more patient-friendly way for children to get a correct diagnosis.

Key takeaways

This study explores a new, faster way to diagnose why kids drink and pee a lot.
It uses a special copeptin blood test after a simple drink, hoping to replace difficult older tests.
The goal is to provide a more comfortable and accurate diagnosis for children.
Participation involves blood tests and potentially an MRI, but no overnight hospital stays for the main tests.
Your child's medical care will be monitored closely throughout the process.
You can withdraw your child from the study at any time.

Who may be eligible?

This study is looking for children aged between 2 and 18 years old who are drinking and peeing much more than usual. Specifically, their bodies need to be passing a large amount of very dilute urine for their age and size. Before joining, their initial blood test for copeptin must show a level below 30 pmol/L.

For your child to be included, both parents or legal guardians must agree for them to take part in the study. The study team will make sure to explain everything clearly so you can make an informed decision.

There are several reasons why a child might not be able to join. These include having certain health conditions like diabetes, kidney problems, specific hormonal imbalances not related to this study, or serious dehydration. Also, if a child cannot have an MRI scan or has had a bad reaction to arginine before, they won't be able to participate. Girls who are pregnant or may be pregnant will also not be able to join.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Is your child aged between 2 and 18 years old?
Does your child drink and pee much more than usual?
Have both parents/guardians agreed to their child's participation?
Does your child NOT have diabetes, severe kidney problems, or similar serious health issues?
Is your child NOT severely dehydrated when starting the study?
Is your child able to have an MRI if needed, and without past adverse reactions to arginine?

Answer every question to see your result.

What does participation involve?

If your child joins the study, the first step is to have some routine blood tests and an initial copeptin blood test. These will be done after your child hasn't eaten since midnight but has not had their water restricted.

If the initial copeptin level is below 30 pmol/L, your child will be invited back for a special test. This involves starting at 8 am, where your child will be given a specific amount of arginine (an amino acid) through a drip over 30 minutes. During and after this, several small blood samples will be taken at different times (before the drip, then at 45, 60, 90, and 120 minutes after the drip starts) to measure copeptin levels. This part of the test lasts about 2 hours.

Based on these results, some children might have an MRI scan of their brain, specifically looking at the pituitary gland. If the MRI shows a problem, they will start specific treatment. For others, a slight reduction in water intake will be advised. All children will have a follow-up appointment about a month later to check how they are doing clinically and with further blood tests. The total duration of active participation for the main tests would be a few hours on two separate occasions, plus a follow-up visit and any subsequent appointments needed for diagnosis and management.

Potential risks and benefits

Participating in this study might offer your child the potential benefit of a quicker and more accurate diagnosis for their condition, possibly avoiding the need for the older, more uncomfortable water deprivation test. While the study primarily aims to improve diagnostic methods for future patients, your child's care will be closely monitored, and any necessary treatments will be initiated based on the findings. Potential risks include discomfort from blood draws and the arginine infusion, which is usually well-tolerated but, like any medicine, can sometimes have side effects. There's also the need for an MRI in some cases. You have the full right to withdraw your child from the study at any time, for any reason, without it affecting their medical care.

Locations (14)

CHU Angers
Verified postcode
Angers, France
CHU de Bordeaux
Verified postcode
Bordeaux, France
CHU Lille
Verified postcode
Lille, France
HCL
Verified postcode
Lyon, France
Assistance Publique Hopitaux de Marseille
Verified postcode
Marseille, France
CHU Montpellier
Verified postcode
Montpellier, France
CHU Nantes
Verified postcode
Nantes, France
CHU Nice
Verified postcode
Nice, France
AP-HP
Verified postcode
Paris, France
CH Pau
Verified postcode
Pau, France
CHU Reims
Verified postcode
Reims, France
CHU Rennes
Verified postcode
Rennes, France

Common questions

What is polyuria-polydipsia syndrome?

It means peeing a lot and feeling very thirsty. Doctors need to find out why this is happening.

What is copeptin?

Copeptin is a marker in your blood that tells doctors about a hormone that controls how your body handles water.

What is an arginine stimulation test?

It's a test where your child is given a special drink (arginine) through a drip, and then blood samples are taken to see how hormone levels change.

Will my child have to stay in the hospital?

No, the main tests are short (a few hours) and don't involve an overnight stay, which is one of the benefits of this new approach.

What if my child can't have an MRI?

If an MRI is not possible, your child would not be able to participate in the study.

How to find out more

Rachel REYNAUD

rachel.reynaud@ap-hm.fr 0491388040 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.