Validation of New Diagnostic Indices to Simplify Hyponatremia Therapy Assessment in Patients on Thiazide Diuretics

NCT ID: NCT06381934

Last Updated: 2025-12-16

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

136 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-05-06

Study Completion Date

2027-04-30

Brief Summary

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This study is looking at two new parameters, aSID and ChU, to see if these can help physicians to distinguish between different causes of low sodium levels (hyponatremia) in Patients taking a medicament against high blood pressure (thiazide). Researchers also want to see if using these new parameters to decide on treatment works just as well, or better, than the current standard treatments.

Detailed Description

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Thiazide or thiazide-like diuretics associated hyponatremia (thiazide associated hyponatremia, TAH) has a high prevalence in hospitalized patients. Patients might present either with a hypovolemic hyponatremia due to volume loss as a diuretic effect of thiazide, or with a syndrome of inadequate antidiuresis (SIAD) like hyponatremia in need of fluid restriction. Canonical urine indices are not useful in differential diagnosis, being directly influenced by thiazide itself. Current guidelines suggest the use of a clinical volume status assessment, but this approach has a poor diagnostic performance, with less than 50% of patients being rightly diagnosed thru that. The investigators showed in a retrospective analysis the possible role of strong apparent ion difference (aSID) and of chloride and potassium levels in urine (ChU) in differential diagnosis of TAH. The goal of this study is to investigate prospectively whether implementation of aSID and, in case of inconclusive aSID, ChU, allows a correct differential diagnosis and treatment of TAH.

Conditions

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Thiazide Associated Hyponatremia

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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Standard Care Group

TAH patients randomised to the Standard Care Group will be followed by a physician not involved in the study.

Group Type ACTIVE_COMPARATOR

Standard Care

Intervention Type OTHER

Standard diagnosis and therapy procedures at physician's discretion.

aSID/ChU Guided Therapy Group

TAH patients randomised to the aSID/ChU Guided Therapy Group will have aSID and ChU determined and, depending on the results, will be assigned to fluid administration with saline or drinking restriction.

Group Type ACTIVE_COMPARATOR

aSID/ChU Guided Therapy

Intervention Type OTHER

Stopping of thiazide therapy. Measure aSID:

* aSID between 39 and 42 mmol/l : measure ChU

* ChU lower than 15mmol/l : fluid administration (0.9% NaCl infusion, 250-500 ml over 2 hours followed by 10-20 ml/kg/24h)
* ChU higher than 14.9 mmol/l : drinking restriction (of at least 50% of usual drinking volume)
* aSID higher than 42 mmol/l : fuid administration (fluid administration (0.9% NaCl infusion, 250-500 ml over 2 hours followed by 10-20 ml/kg/24h)
* aSID lower than 39 mmol/l : drinking restriction (of at least 50% of usual drinking volume)

The aSID/ChU guided therapy will take place for a minimum of 1- and a maximum of 3 days after enrolment. Treatment and adherence to the treatment will be assessed and re-evaluated at least daily for 3 days or till discharge or sodium normalization.

Interventions

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Standard Care

Standard diagnosis and therapy procedures at physician's discretion.

Intervention Type OTHER

aSID/ChU Guided Therapy

Stopping of thiazide therapy. Measure aSID:

* aSID between 39 and 42 mmol/l : measure ChU

* ChU lower than 15mmol/l : fluid administration (0.9% NaCl infusion, 250-500 ml over 2 hours followed by 10-20 ml/kg/24h)
* ChU higher than 14.9 mmol/l : drinking restriction (of at least 50% of usual drinking volume)
* aSID higher than 42 mmol/l : fuid administration (fluid administration (0.9% NaCl infusion, 250-500 ml over 2 hours followed by 10-20 ml/kg/24h)
* aSID lower than 39 mmol/l : drinking restriction (of at least 50% of usual drinking volume)

The aSID/ChU guided therapy will take place for a minimum of 1- and a maximum of 3 days after enrolment. Treatment and adherence to the treatment will be assessed and re-evaluated at least daily for 3 days or till discharge or sodium normalization.

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

* Hospitalized patients presenting at University Hospital Basel
* aged 18 years or older
* able to give informed consent as documented by signature
* with serum sodium level \< 130 mmol/l and serum osmolality \< 300 mOsm/kg
* with treatment with thiazide or thiazide-like diuretic

Exclusion Criteria

* symptomatic hyponatremia in need of 3% hypertonic solution or intensive care treatment
* inability or contraindications to undergo the trial (i.e., any acute severe cardiovascular event requiring an immediate intervention)
* decompensated liver cirrhosis CHILD C
* decompensated heart failure NYHA III or higher
* severe valve impairment
* untreated adrenal insufficiency
* severe kidney disease in need of dialysis
* pregnancy or breastfeeding
* end of life care
* inability to follow the study procedures (i.e., language problem, dementia or critical illness).
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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University Hospital, Basel, Switzerland

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Laura Potasso, Dr. med. sc.

Role: PRINCIPAL_INVESTIGATOR

University Hospital, Basel, Switzerland

Locations

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University Hospital Basel

Basel, , Switzerland

Site Status RECRUITING

Countries

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Switzerland

Central Contacts

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Laura Potasso, Dr. med. sc.

Role: CONTACT

+41 61 328 58 76

Facility Contacts

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Laura Potasso, Dr. med. sc.

Role: primary

+41 61 328 58 76

Mirjam Christ-Crain, Prof. Dr. med.

Role: backup

+41 61 328 70 80

References

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Vogt K, Widmer D, Kirsch M, Christ-Crain M, Potasso L. Validation of new diagnostic indices to simplify hyponatremia therapy assessment in patients on thiazide diuretics: study protocol of a randomized, controlled, parallel-group trial (THAT-Study). Trials. 2025 Jul 11;26(1):242. doi: 10.1186/s13063-025-08925-4.

Reference Type DERIVED
PMID: 40646556 (View on PubMed)

Other Identifiers

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2024-00335; kt23ChristCrain4

Identifier Type: -

Identifier Source: org_study_id