Copeptin After a Subcutaneous Stimulation With Glucagon in Adults

What Was Tested

In this not phased trial, researchers set out to test Glucagon.

This study is to evaluate copeptin values after the subcutaneous injection of glucagon in adults (healthy volunteers and patients with diabetes insipidus or primary polydipsia).

It is to investigate whether glucagon stimulates the release of copeptin as a surrogate of vasopressin.

It had two arms (groups): study part 1: healthy adult volunteers (experimental) and study part 2: adult patients with primary polydipsia or central diabetes insipidus (experimental).

22 Healthy volunteers: The half of the study group will start with test day A (injection of glucagon), followed by test day B (injection of placebo) and the other half will start with test day B (injection of placebo), followed by test day A (injection of glucagon).

The registry classes the interventions as diagnostic test.

More on the Plan

The differentiation between central diabetes insipidus (cDI) and primary polydipsia (PP) is cumbersome.

To date the test with the highest diagnostic accuracy is copeptin measurement after hypertonic saline Infusion.

Instead of hypertonic saline Infusion, arginine infusion - known to stimulate growth hormone - is a potent stimulator of the neurohypophysis and provides a new diagnostic tool in the differential diagnosis of cDI.

In analogy to the known stimulatory effect of arginine Infusion it is hypothesized that glucagon might stimulate the posterior pituitary gland and could therefore be a novel diagnostic test in the polyuria-polydipsia syndrome.

Who Took Part

The registry lists 42 actual participants took part.

It was open to people of any sex aged from 18 years up to 60 years.

Healthy volunteers could join, not only people with the condition.

Examples of who could join: No medication except hormonal contraception. Documented primary polydipsia or diabetes insipidus based on a water deprivation test or hypertonic saline Infusion.

The full record lists 3 inclusion and 19 exclusion criteria; among the exclusions: BMI \> 25kg/m2 or \< 18.5 kg/m2; participation in a trial with investigational drugs within 30 days; vigorous physical exercise within 24 hours before the study participation.

How the Study Was Run

It was run as a randomized, crossover and triple-blind study.

Random assignment meant chance, not the researchers, decided who got Glucagon and who got the comparison, which limits bias.

Each person switched between Glucagon and the comparison at some point, usually with a gap in between.

As a double-blind Glucagon study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant, care provider and investigator.

It started in 2020-09-28 with completion listed for 2021-05-30.

It ran at 1 site in Switzerland.

Its stated primary purpose is diagnostic.

What Was Measured

It also tracked 11 secondary outcomes, for example Change in copeptin values, Change in growth hormone (GH), Change in prolactin, Change in plasma sodium, Change in plasma osmolality and Change in oxytocin.

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of Glucagon in 42 people.

The trial is marked completed; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Glucagon compound page, all human trials.