Gitelman Syndrome
Conditions
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.
Interventions
DIETARY_SUPPLEMENTSalt (NaCl)
12 grams of salt (NaCl) per day
OTHERPlacebo
Placebo
Sponsors
Dutch Kidney Foundation
Radboud University Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Intervention model description
Single subject multiple randomized double-blinded multi-crossover placebo-controlled trials (N-of-1 trials)
Eligibility
Sex/Gender
ALL
Age
16 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Genetically-proven, symptomatic Gitelman syndrome * Written informed consent
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| Change in serum chloride | Baseline, week 4, week 8, week 12, week 16, week 20, week 24 | Change in serum chloride |
| Change in serum bicarbonate | Baseline, week 4, week 8, week 12, week 16, week 20, week 24 | Change in serum bicarbonate |
| 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 |
| 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 serum sodium | Baseline, week 4, week 8, week 12, week 16, week 20, week 24 | Change in serum 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 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 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 |
| 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 |
| Weight | Baseline, week 4, week 8, week 12, week 16, week 20, week 24 | Body Weight |
| Muscle strength | Baseline, week 4, week 8, week 12, week 16, week 20, week 24 | Muscle strength will be measured by hand grip dynamometer |
| 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 serum magnesium | Baseline, week 4, week 8, week 12, week 16, week 20, week 24 | Change in serum magnesium |
Countries
Italy, Netherlands
Outcome results
None listed