Effects of Intravenous [Pyr1]Apelin-13 on Healthy Volunteers With Artificially Induced SIAD

What Was Tested

The trial (not phased) is built around Apelin.

Hyponatremia is a common electrolyte imbalance which often results from hormonal disregulation.

The study aims to investigate whether the apelin hormone, which plays a role in regulating salt and water balance in the body, can be used to treat hyponatremia.

The study will involve healthy volunteers who will be given a medication that causes their bodies to retain water, thus inducing a temporary hyponatremia state.

It had eight arms (groups): one (experimental), one (experimental), one (experimental), one (experimental) and one (experimental).

The intervention sequence is assigned in random order. Each intervention corresponds to a visit of 11h. A wash-out period of 2 to 8 weeks is planned between interventions. Artificial SIAD induction (water loading and desmopressin administration) is performed.

The intervention sequence is assigned in random order. Each intervention corresponds to a visit of 11h. A wash-out period of 2 to 8 weeks is planned between interventions. Artificial SIAD induction (water loading and desmopressin administration) is performed.

The intervention sequence is assigned in random order. Each intervention corresponds to a visit of 11h. A wash-out period of 2 to 8 weeks is planned between interventions. Artificial SIAD induction (water loading and desmopressin administration) is performed.

The registry classes the interventions as drug.

More on the Plan

It is usually classified according to its duration, its biochemical findings (hypotonic/isotonic/hypertonic, mild/moderate/profound), its symptoms severity (mild/moderate/severe) and volume status (hypovolemic/euvolemic/hypervolemic).

Hyponatremia is recognized as a marker of poor prognosis in multiple diseases, but the extent of its causative role has not been quantified to date.

The most common etiology of euvolemic hyponatremia is the syndrome of inappropriate antidiuresis (SIAD) which is also the main etiology of hyponatremia overall.

This leads to free water retention, thereupon to extracellular volume expansion and a subsequent renal sodium loss resulting in hypotonic hyponatremia.

Who Took Part

Enrollment: 15 actual participants took part.

It was open to people of any sex aged from 18 years up to 65 years.

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

Examples of who could join: Informed consent as documented by signature. Age 18 to 65 years. Clinically euvolemic status.

The full record lists 5 inclusion and 44 exclusion criteria; among the exclusions: known or suspected allergy to trial product or related products or history of multiple and/or severe allergic reaction to drugs (including study drugs) or food; pregnancy, wish to become pregnant during study period or breastfeeding; overt cardiovascular disease or abnormality in screening ecg.

How the Study Was Run

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

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

Neither the participants nor the staff measuring them knew who was on Apelin, so expectations could not easily colour the readings.

Those kept unaware of assignments: participant and care provider.

It started in 2024-03-01 with completion listed for 2025-03-18.

It ran at 1 site in Switzerland.

Its stated primary purpose is treatment.

What Was Measured

The main thing measured (primary outcome): Total urinary excretion (ml) (time frame: assessment between timepoint 0 hours and timepoint +4 hours).

It also tracked 6 secondary outcomes, for example Hourly and total urinary excretion (ml), Change in electrolyte free water clearance (ml/min), Change in free water clearance (ml/min), Change in plasma sodium (mmol/l) and Change in body weight (kg).

What This Means in Plain Language

Put simply, this is a not phased, non-randomized trial of Apelin in 15 people.

Its size is small, so on its own it can only give an early look.

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

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