N/A
N=38
Dietary Sodium's Effect on Urinary Sodium and Dopamine Excretion in Patients With Postural Tachycardia Syndrome
Postural Orthostatic Tachycardia Syndrome
Bottom Line
View on ClinicalTrials.gov: NCT01563107 ↗Enrolled (actual)
38
Serious AEs
0.0%
Results posted
Jan 2022
Primary outcome: Primary: 24hr Urinary Sodium — 16.8; 280; 14.7; 245 milliequivalents
Study Design & Population
- Study type
- Interventional
- Phase
- N/A
- Interventions
- Plasma Volume (Radiation); Exercise Capacity Test - Bicycle (Procedure); Posture Study (Procedure)
- Age
- Adult · 18+ yrs
- Sex
- Female
- Sponsor
- Vanderbilt University Medical Center
- Primary completion
- Dec 2020
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY 24hr Urinary Sodium |
16.8; 280; 14.7; 245 | — |
| PRIMARY 24hr Urinary Dopamine |
223; 236; 202; 205 | — |
| SECONDARY Plasma Volume |
2805; 3032; 2362; 2633 | — |
| SECONDARY Magnitude of Orthostatic Tachycardia |
23; 19; 60; 46 | — |
| SECONDARY Upright Symptom Score |
1; 0; 30; 19 | — |
| SECONDARY Urinary Sodium Following Change in Dietary Sodium Days 1-2 |
145; 134; 143; 160 | — |
| SECONDARY Urinary Dopamine Following Change in Dietary Sodium Days1-2 |
228; 200; 207; 202 | — |
| SECONDARY Urinary Sodium Following Change in Dietary Sodium Days 2-3 |
88.0; 199; 70.1; 154 | — |
| SECONDARY Urinary Sodium Following Change in Dietary Sodium Days 3-4 |
32.7; 230; 28.9; 222 | — |
| SECONDARY Urinary Sodium Following Change in Dietary Sodium Days 4-5 |
17.3; 216; 21.6; 264 | — |
| SECONDARY Urinary Sodium Following Change in Dietary Sodium Days 5-6 |
21.6; 260; 18.2; 242 | — |
| SECONDARY Urinary Dopamine Following Change in Dietary Sodium Days 2-3 |
183; 185; 205; 171 | — |
| SECONDARY Urinary Dopamine Following Change in Dietary Sodium Days 3-4 |
222; 193; 203; 177 | — |
| SECONDARY Urinary Dopamine Following Change in Dietary Sodium Days 4-5 |
213; 202; 205; 214 | — |
| SECONDARY Urinary Dopamine Following Change in Dietary Sodium Days 5-6 |
227; 210; 211; 199 | — |
Summary
Patients with Postural Tachycardia Syndrome (POTS) may not adequately expand their plasma volume in response to a high sodium diet. Mechanisms involved in the regulation of plasma volume, such as the renin-angiotensin-aldosterone system and renal dopamine (DA), may be impaired in POTS and may respond inappropriately to changes in dietary sodium. The investigators propose that the changes in urinary sodium and dopamine excretion caused by consuming low-sodium and high-sodium diets will be different between patients with POTS and healthy volunteers. The purpose of this study is to determine (1) whether changes in dietary sodium level appropriately influence sodium excretion in POTS; (2) whether changes in dietary sodium level appropriately influence DA excretion in POTS; (3) whether a high dietary sodium level appropriately expands plasma volume in POTS; and (4) whether patients with POTS have improvements in their orthostatic tachycardia and symptoms as a result of a high dietary sodium level.
Eligibility Criteria
Inclusion Criteria
- Premenopausal patients with POTS and healthy volunteers, 18-50 years old, who are non-smokers and free of medications with the potential to influence blood pressure
- Patients diagnosed with postural tachycardia syndrome by the Vanderbilt Autonomic Dysfunction Center
- Patients who Increase heart rate ≥30 beats/min with position change from supine to standing (10 minutes)
- For patients, chronic symptoms consistent with POTS that are worse when upright and get better with recumbence
- Only female participants are eligible. Since 80-90% of POTS patients are female, and there can be differences in measures with the menstrual cycle, including a small number of males might introduce a significant amount of noise.
- Able and willing to provide informed consent
Exclusion Criteria
- Smokers
- Overt cause for postural tachycardia, i.e., acute dehydration
- Significant cardiovascular, pulmonary, hepatic, or hematological disease by history or screening results
- Positive pregnancy test or breastfeeding
- Hypertension defined as BP>145/95 off medications when supine or needing antihypertensive medication
- Other factors which in the investigator's opinion would prevent the participant from completing the protocol, including poor compliance during previous studies or an unpredictable schedule
- Unable to give informed consent
Data sourced from ClinicalTrials.gov (NCT01563107). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.