Assessing Aldosterone & Sodium Regulation in Postural Orthostatic Tachycardia Syndrome

Age: 18 - 65

Sex: Female

Trial Phase: Academic

Sponsor: Vanderbilt University

Must not be taking: Antihypertensives

Disqualifiers: Smokers, Cardiovascular disease, Pregnant, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 6

110 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications. However, if you are on antihypertensive medication, you may not be eligible to participate.

What data supports the effectiveness of the treatment for postural orthostatic tachycardia syndrome?

The research suggests that understanding the body's response to changes in position and exercise can help manage postural orthostatic tachycardia syndrome (POTS). Studies show that measuring heart rate, blood pressure, and blood volume during different activities can provide insights into the condition, which may guide effective treatment strategies. ^{1 2 3 4 5}

Is the treatment for postural orthostatic tachycardia syndrome safe for humans?

The studies reviewed focus on understanding the body's response to postural changes and exercise in people with postural orthostatic tachycardia syndrome (POTS), but they do not provide specific safety data for the treatment itself. However, these types of tests, like the head-up tilt test and exercise tests, are generally considered safe and are commonly used in clinical settings to assess cardiovascular function. ^{1 2 3 6 7}

How does this treatment for POTS differ from other treatments?

This treatment focuses on understanding and regulating aldosterone and sodium levels, which are often imbalanced in POTS patients, potentially due to adrenal dysfunction. This approach is unique as it targets the hormonal regulation aspect of the condition, which is not typically addressed by standard treatments that focus on managing symptoms like heart rate and blood pressure. ^{1 2 4 7 8}

What is the purpose of this trial?

The purpose of the study is to determine whether patients meet criteria for Postural Tachycardia Syndrome (or not) and have reduced blood volume (or not). Both of these are important screening elements to Aim 3 of a National Institutes of Health Grant. The purposes of Aim 3 are to determine 1. whether a high dietary sodium level appropriately expands plasma volume in Postural Orthostatic Tachycardia, 2. whether plasma renin activity and aldosterone are modified appropriately by changes in dietary sodium in Postural Tachycardia Syndrome and 3. whether patients with Postural Tachycardia Syndrome have improvements in their orthostatic tachycardia and symptoms as a result of a high dietary sodium level.

Research Team

Alfredo J Gamboa, MD

Principal Investigator

Vanderbilt University Medical Center

Eligibility Criteria

This trial is for women aged 18-50 who may have Postural Tachycardia Syndrome (POTS) or are healthy but sedentary. Participants should not smoke, be pregnant, highly athletic, or have significant health issues like heart disease. They must be able to consent and follow the study schedule.

Inclusion Criteria

People with suspected POTS (Postural Orthostatic Tachycardia Syndrome) and those who are healthy.

I am a female.

Able and willing to provide informed consent

Exclusion Criteria

Pregnant (positive pregnancy test) or breastfeeding

I do not have severe anxiety or somatization symptoms.

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

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Evaluation

Evaluation of autonomic nervous system status and initial assessments

3 days

3 visits (in-person)

Testing

Autonomic function testing, posture study, measurement of total blood volume, and exercise capacity test

2 days

2 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after testing

4 weeks

Treatment Details

Interventions

• Autonomic Function Testing
• Exercise Capacity Test
• Measurement of Total Blood Volume
• Posture Study

Trial Overview The study aims to see if high sodium diets can increase blood volume and improve symptoms in POTS patients by testing their exercise capacity, autonomic functions, posture response, and total blood volume before and after dietary changes.

Participant Groups

Group I: All participants Experimental Treatment 4 Interventions

All participants will be administered all procedures as described previously. Interventions: Autonomic Function Testing, Posture Study ,Measurement of Total Blood Volume ,Exercise Capacity Test

Who Is Running the Clinical Trial?

Vanderbilt University

Lead Sponsor

Trials

714

Recruited

6,143,000+

National Heart, Lung, and Blood Institute (NHLBI)

Collaborator

Trials

3,987

Recruited

47,860,000+

National Institutes of Health (NIH)

Collaborator

Trials

2,896

Recruited

8,053,000+

References

1. Netherlands pubmed.ncbi.nlm.nih.gov

Orthostatic tachycardia with different onset time in patients with orthostatic intolerance. [2019]

2. Netherlands pubmed.ncbi.nlm.nih.gov

Differences in neurohumoral and hemodynamic response to prolonged head-up tilt between patients with high and normal standing norepinephrine forms of postural orthostatic tachycardia syndrome. [2018]

3. United States pubmed.ncbi.nlm.nih.gov

Reduced stroke volume during exercise in postural tachycardia syndrome. [2013]

4. China pubmed.ncbi.nlm.nih.gov

[Relationship between 24-hour urinary sodium and renin-angiotensin-aldosterone system in children with postural tachycardia syndrome]. [2018]

5. United States pubmed.ncbi.nlm.nih.gov

Total peripheral vascular resistance, cardiac output, and plasma C-type natriuretic Peptide level in children with postural tachycardia syndrome. [2015]

6. Netherlands pubmed.ncbi.nlm.nih.gov

Hemodynamic profile and heart rate variability in hyperadrenergic versus non-hyperadrenergic postural orthostatic tachycardia syndrome. [2017]

7. United States pubmed.ncbi.nlm.nih.gov

Normal autonomic neurophysiology of postural orthostatic tachycardia and recommended physiological assessments in postural orthostatic tachycardia syndrome. [2021]

8. Netherlands pubmed.ncbi.nlm.nih.gov

Adrenal gland response to adrenocorticotropic hormone is intact in patients with postural orthostatic tachycardia syndrome. [2023]