Salt Supplementation in Gitelman Syndrome

Not Applicable

Completed

• Conditions: Gitelman Syndrome
• Interventions: Dietary Supplement: Salt (NaCl); Other: Placebo

• Registration Number: NCT04995627
• Lead Sponsor: Radboud University Medical Center

Brief Summary

The purpose of this study is to determine the effect of salt (NaCl) supplementation on serum potassium and clinical signs and symptoms in patients with Gitelman syndrome.

Detailed Description

Single subject multiple randomized double-blinded multi-crossover placebo-controlled trials (N-of-1 trials) will be performed. Participants will enroll the study after giving written informed consent. The individual trials will consist of 3 treatment blocks which each contain a 4-week treatment period of salt supplementation (12 grams of NaCl) and a 4-week treatment period of placebo, in a randomized, blinded order. After each period of 4 weeks, outcomes measures will be measured.

Study Timeline

• Study Start: 2021-04-19
• Study First Submitted: 2021-07-18
• Study First Submitted QC: 2021-07-29
• Study First Posted: 2021-08-09
• Primary Completion: 2024-09-01
• Study Completion: 2024-09-01
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-18
• Last Update Posted: 2024-11-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 21

Inclusion Criteria

• Genetically-proven, symptomatic Gitelman syndrome
• Written informed consent

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Exclusion Criteria

• inability to discontinue potassium-sparing diuretics, mineralocorticoid antagonists and NSAIDs; this means inability to reach a potassium level of 2.5 mmol/L or higher with maximally tolerable potassium supplementation after discontinuation of potassium-sparing diuretics
• pregnancy

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Salt (NaCl)	Salt (NaCl)	12 grams (12 capsules) of NaCl per day Note: participants will be treated with active and placebo comparator (N-of-1 trial design)
Placebo	Placebo	12 capsules of placebo per day Note: participants will be treated with active and placebo comparator (N-of-1 trial design)

Primary Outcome Measures

Name	Time	Method
Change in serum Potassium	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in serum potassium
Change in symptoms measured by personalized symptom score sheet	Weekly (week 0 till week 24)	Symptoms will be scored via a personalized symptom score sheet, which will be composed with the individual participant. Symptoms will be scored at a range from 0 - 10

Secondary Outcome Measures

Name	Time	Method
Change in serum bicarbonate	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in serum bicarbonate
Change in serum renin	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in serum renin
Change in fractional urinary excretion of potassium	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in fractional urinary excretion of potassium
Change in fractional urinary excretion of sodium	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in fractional urinary excretion of sodium
Change in fractional urinary excretion of magnesium	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in fractional urinary excretion of magnesium
Change in urinary excretion of aldosterone	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in urinary excretion of aldosterone
Gitelman symptom questionnaire	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	With the Gitelman symptom questionnaire, symptoms can be scored for frequency of apperance and severity. This questionnaire also contains the 36-Item Short Form Health Survey (RAND SF-36) quality of life questionnaire
Weight	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Body Weight
Change in serum chloride	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in serum chloride
Change in fractional urinary excretion of chloride	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in fractional urinary excretion of chloride
Change in urinary calcium/creatinine ratio	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in urinary calcium/creatinine ratio
Change in urinary excretion of renin	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in urinary excretion of renin
Change in serum sodium	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in serum sodium
Change in serum magnesium	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in serum magnesium
Change in serum calcium	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in serum calcium
Change in serum creatinine	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in serum creatinine
Change in serum aldosterone	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Change in serum aldosterone
Blood pressure (including orthostatic hypotension measurement)	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Measurement of blood pressure including measurement of orthostatic blood pressure
Muscle strength	Baseline, week 4, week 8, week 12, week 16, week 20, week 24	Muscle strength will be measured by hand grip dynamometer

Trial Locations

Locations (3)

University Hospital of University of Campania "L. Vanvitelli"; 🇮🇹 Naples, Italy

Radboudumc; 🇳🇱 Nijmegen, Gelderland, Netherlands

Erasmus MC; 🇳🇱 Rotterdam, Zuid-Holland, Netherlands