Postural Orthostatic Tachycardia SyndromeNCT05344599
Evaluating the Prevalence of Acute Hepatic Porphyria in Postural Tachycardia Syndrome
An observational study of Postural Orthostatic Tachycardia Syndrome and Acute Hepatic Porphyria, run by Vanderbilt University Medical Center at 1 site in United States.
Trial summary
Postural Tachycardia Syndrome (POTS) is the most common autonomic disorder and is estimated to affect 3,000,000 individuals in the United States, with 80-85% of patients being women. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Postural Orthostatic Tachycardia Syndrome, Acute Hepatic Porphyria
- What is being tested?
- Autonomic Function Testing, Genetic Testing and Urine Testing
- Type of treatment
- Injection or infusion
- How many people
- 70 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Jan 2022to 30 Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Adult, Older adult
Study population: Postural Tachycardia Syndrome
Who may be able to join
- Age 18 - 65 years
- Individuals having an established diagnosis of POTS defined as the presence of presyncopal symptoms for more than 6 months and orthostatic tachycardia (>30 bpm increase in HR within 10 min after assuming upright position)
- The present of one of the following criteria:
- 3.1 Family history of acute hepatic porphyria 3.2 Unexplained recurrent (more than one), prolonged (>24 hours) episode of severe, diffuse (poorly localized) abdominal pain AND at least TWO of the following:
- Red to brownish urine.
- Blistering skin lesions on sun-exposed areas.
Show all 9Show fewer
- Peripheral nervous system manifestations occurring around the time of abdominal pain (i.e., motor neuropathy (paresis), sensory neuropathy (numbness, tingling, limb pain).
- Central nervous system manifestations occurring around the time of abdominal pain (i.e. confusion, anxiety, seizures, hallucinations).
- Autonomic nervous system manifestations occurring around the time of abdominal pain (i.e. hyponatremia(Na<lower limit of normal)), tachycardia, hypertension, nausea and vomiting, constipation).
Who cannot join
- Pregnant or breastfeeding women
- type 2 diabetes mellitus
- History of alcohol or drug abuse
- Inability to provide informed consent or comply with protocol
Trial locations and contacts
1 site in 1 country.
United States1 site
Vanderbilt University Medical Center
Nashville, Tennessee, 37232
About this study
Official title: Estimating the Frequency and Neuro-Hormonal Characteristics of Acute Hepatic Porphyria in Postural Tachycardia Syndrome
Postural Tachycardia Syndrome (POTS) is the most common autonomic disorder and is estimated to affect 3,000,000 individuals in the United States, with 80-85% of patients being women. The condition is characterized by a rapid increase in heart rate (HR) that occurs on standing, and chronic symptoms of cerebral hypoperfusion leading to lightheadedness, dizziness, and blurred vision.
The acute hepatic porphyrias(AHP)are among the diseases that present with autonomic cardiovascular(tachycardia)and neurovisceral symptoms (abdominal pain) among others; they present with acute exacerbations Given that there is available treatment for AHP that change the natural progression of the disease, study focuses to investigate the occurrence of AHP in POTS and determine the clinical and neuro-hormonal characteristic of the POTS subgroup that will likely benefit from AHP screening.
This study has one visit that involves, answering some questionnaires, coming to the lab for blood work, genetic testing, and some autonomic function tests. About 50 people will take part in this study.
Read the detailed description
Postural Tachycardia Syndrome (POTS) affects ~3 million young women in the United States.(1)These patients have a low quality of life because of chronic presyncopal symptoms, and orthostatic tachycardia that occur while standing. POTS can be the initial presentation of an underlying illness. A substantial group of patients with POTS reported that their symptoms started after an acute illness, surgical intervention, substantial weight loss or after ingesting certain medications. These are the same triggers for acute AHP attacks.
Furthermore, the demographic characteristics of AHP overlaps with that of POTS. AHP also affects primarily young women, in their reproductive age. POTS can have a diverse presentation, some patients present with axonal autonomic neuropathy, and severe gastrointestinal symptoms which are co-morbid conditions also present in chronic AHP.
It is within this context that investigators propose to assess the occurrence of AHP in the general POTS population, identify its clinical presentation and neuro-hormonal characteristics.
Rationale and Endpoints:
- To evaluate occurrence of AHPs in POTS patients with autonomic and neurovisceral symptoms referred to a National Referral Center for the treatment of Autonomic Disorder.
- To determine the autonomic and neuro-hormonal characteristics of AHP-POTS patients compared with POTS patients
Enrollment:
This is a cross-sectional study conducted at the Vanderbilt Autonomic Dysfunction Clinic (ADC). Investigators plan to enroll patients with suspicions of POTS who are referred to the ADC for evaluation and diagnosis.
Study visit:
Single study visit.
Participants will be asked to complete an autonomic symptoms assessment questionnaire (COMPASS 31), and quality of life EQ-5D.
The following laboratory analyses will be performed:
Blood: CBC, CMP, Iron studies (Ferritin and iron studies) Urine PBG, ALA and porphyrins in a spot urine sample with results normalized to urine creatinine.
Genetic testing (Acute hepatic porphyria panel) .
Autonomic function test.
Supine and Standing plasma norepinephrine will be obtained for evaluation of neuro-hormonal changes during orthostasis.
Statistical Analyses
This is a pilot study that will estimate the occurrence of AHPs in POTS patients referred to a National Referral Center for the Treatment of Autonomic Disorders. There is no data available on the prevalence of AHPs in POTS. The prevalence of AHP is one in 6,000 in whites. [ref. Hepatol commun 2019 feb 3(2): 193-206] Given that there are overlapping of symptoms between AHP and POTS, expected that AHP would be overrepresented in POTS patients. The plan is to enroll 50 POTS patients in this pilot study.
Data Analysis Plan:
Standard graphing and screening techniques will be used, to detect outliers and to ensure data accuracy. Continuous endpoints will be assessed for normality. If normality is violated, data transformation will be applied or non-parametric analysis methods will be considered. Investigators will provide summary statistics for both continuous and categorical variables by subject groups (POTS and AHP-POTS). All hypotheses will be tested, at the level of α=0.05. SPSS (version 23.0, SPSS, Chicago, IL) will be used and the open-source statistical package R (R Core Team, 2019 for analyses.
- Being tested
- Autonomic Function Testing, Genetic Testing, Urine Testing, Blood laboratory Testing
- Keywords
- POTS
- Medical subject headings
- Postural Orthostatic Tachycardia Syndrome, Coproporphyria, Hereditary
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Autonomic Function TestingDiagnostic test
Autonomic function test (orthostatic blood pressure and heart rate response to tilt, heart rate response to deep breathing, the Valsalva ratio, and beat-to-beat blood pressure measurements during phases II and IV of the Valsalva maneuver, tilt, and deep breathing). These combined tests provide a measurement of adrenergic, cardiovagal responses.
Genetic TestingDiagnostic test
Genetic testing: for Acute hepatic porphyria panel - with intent to use Saliva kit
Urine TestingDiagnostic test
Urine PBG, ALA and porphyrins in a spot urine sample with results normalized to urine creatinine
Blood laboratory TestingDiagnostic test
To determine the following laboratory analyses:
CBC, CMP, Iron studies (Ferritin and iron studies)
What is being measured
The primary outcome is the main question the study is designed to answer.
AHP Case ascertainment in POTS patients
Evaluating the Prevalence of Acute Hepatic Porphyria in Postural Tachycardia Syndrome
Measured: During the intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Apr 2022
- Study start19 Jan 2022
- Primary completion30 Dec 2024
- Study completion30 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Postural Orthostatic Tachycardia SyndromeStudies of the same condition, open and under way.
- More trials run by Vanderbilt University Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Enrolment
- 70 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Cyndya Shibao, MD, Vanderbilt University Medical Center
- Investigators
- Cyndya Shibao, M.D, Principal investigator, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05344599
- Sponsor's protocol ID
- 210724
- Status last verified
- Sep 2026
- First submitted
- 8 Apr 2022
- Last updated
- 28 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Robertson D; New Collective Author. The epidemic of orthostatic tachycardia and orthostatic intolerance. Am J Med Sci. 1999 Feb;317(2):75-7. doi: 10.1097/00000441-199902000-00001. No abstract available.
PubMed 10037110Garland EM, Raj SR, Black BK, Harris PA, Robertson D. The hemodynamic and neurohumoral phenotype of postural tachycardia syndrome. Neurology. 2007 Aug 21;69(8):790-8. doi: 10.1212/01.wnl.0000267663.05398.40.
PubMed 17709712Schondorf R, Low PA. Idiopathic postural orthostatic tachycardia syndrome: an attenuated form of acute pandysautonomia? Neurology. 1993 Jan;43(1):132-7. doi: 10.1212/wnl.43.1_part_1.132.
PubMed 8423877Raj SR. The Postural Tachycardia Syndrome (POTS): pathophysiology, diagnosis & management. Indian Pacing Electrophysiol J. 2006 Apr 1;6(2):84-99.
PubMed 16943900Loavenbruck A, Iturrino J, Singer W, Sletten DM, Low PA, Zinsmeister AR, Bharucha AE. Disturbances of gastrointestinal transit and autonomic functions in postural orthostatic tachycardia syndrome. Neurogastroenterol Motil. 2015 Jan;27(1):92-8. doi: 10.1111/nmo.12480. Epub 2014 Dec 6.
PubMed 25483980
Study at a glance
From the registry record, last updated by the sponsor on 28 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Estimating the Frequency and Neuro-Hormonal Characteristics of Acute Hepatic Porphyria in Postural Tachycardia Syndrome
- ClinicalTrials.gov ID
- NCT05344599
- Acronym / sponsor ID
- 210724
- Keywords
- POTS
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 70 participants (actual)
- Lead sponsor
- Vanderbilt University Medical CenterUniversity, hospital or other
- Study start
- 19 Jan 2022 (actual)
- Primary completion
- 30 Dec 2024 (actual)
- Study completion
- 30 Dec 2026 (estimated)
- First posted
- 25 Apr 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Postural Tachycardia Syndrome (POTS) is the most common autonomic disorder and is estimated to affect 3,000,000 individuals in the United States, with 80-85% of patients being women. The condition is characterized by a rapid increase in heart rate (HR) that occurs on standing, and chronic symptoms of cerebral hypoperfusion leading to lightheadedness, dizziness, and blurred vision.
The acute hepatic porphyrias(AHP)are among the diseases that present with autonomic cardiovascular(tachycardia)and neurovisceral symptoms (abdominal pain) among others; they present with acute exacerbations Given that there is available treatment for AHP that change the natural progression of the disease, study focuses to investigate the occurrence of AHP in POTS and determine the clinical and neuro-hormonal characteristic of the POTS subgroup that will likely benefit from AHP screening.
This study has one visit that involves, answering some questionnaires, coming to the lab for blood work, genetic testing, and some autonomic function tests. About 50 people will take part in this study.
Detailed description
Postural Tachycardia Syndrome (POTS) affects ~3 million young women in the United States.(1)These patients have a low quality of life because of chronic presyncopal symptoms, and orthostatic tachycardia that occur while standing. POTS can be the initial presentation of an underlying illness. A substantial group of patients with POTS reported that their symptoms started after an acute illness, surgical intervention, substantial weight loss or after ingesting certain medications. These are the same triggers for acute AHP attacks.
Furthermore, the demographic characteristics of AHP overlaps with that of POTS. AHP also affects primarily young women, in their reproductive age. POTS can have a diverse presentation, some patients present with axonal autonomic neuropathy, and severe gastrointestinal symptoms which are co-morbid conditions also present in chronic AHP.
It is within this context that investigators propose to assess the occurrence of AHP in the general POTS population, identify its clinical presentation and neuro-hormonal characteristics.
Rationale and Endpoints:
- To evaluate occurrence of AHPs in POTS patients with autonomic and neurovisceral symptoms referred to a National Referral Center for the treatment of Autonomic Disorder.
- To determine the autonomic and neuro-hormonal characteristics of AHP-POTS patients compared with POTS patients
Enrollment:
This is a cross-sectional study conducted at the Vanderbilt Autonomic Dysfunction Clinic (ADC). Investigators plan to enroll patients with suspicions of POTS who are referred to the ADC for evaluation and diagnosis.
Study visit:
Single study visit.
Participants will be asked to complete an autonomic symptoms assessment questionnaire (COMPASS 31), and quality of life EQ-5D.
The following laboratory analyses will be performed:
Blood: CBC, CMP, Iron studies (Ferritin and iron studies) Urine PBG, ALA and porphyrins in a spot urine sample with results normalized to urine creatinine.
Genetic testing (Acute hepatic porphyria panel) .
Autonomic function test.
Supine and Standing plasma norepinephrine will be obtained for evaluation of neuro-hormonal changes during orthostasis.
Statistical Analyses
This is a pilot study that will estimate the occurrence of AHPs in POTS patients referred to a National Referral Center for the Treatment of Autonomic Disorders. There is no data available on the prevalence of AHPs in POTS. The prevalence of AHP is one in 6,000 in whites. [ref. Hepatol commun 2019 feb 3(2): 193-206] Given that there are overlapping of symptoms between AHP and POTS, expected that AHP would be overrepresented in POTS patients. The plan is to enroll 50 POTS patients in this pilot study.
Data Analysis Plan:
Standard graphing and screening techniques will be used, to detect outliers and to ensure data accuracy. Continuous endpoints will be assessed for normality. If normality is violated, data transformation will be applied or non-parametric analysis methods will be considered. Investigators will provide summary statistics for both continuous and categorical variables by subject groups (POTS and AHP-POTS). All hypotheses will be tested, at the level of α=0.05. SPSS (version 23.0, SPSS, Chicago, IL) will be used and the open-source statistical package R (R Core Team, 2019 for analyses.
Study design
- Observational model
- Case only
- Time perspective
- Cross-sectional
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- Postural Tachycardia Syndrome
Key inclusion criteria (9 listed)
- Age 18 - 65 years
- Individuals having an established diagnosis of POTS defined as the presence of presyncopal symptoms for more than 6 months and orthostatic tachycardia (>30 bpm increase in HR within 10 min after assuming upright position)
- The present of one of the following criteria:
- 3.1 Family history of acute hepatic porphyria 3.2 Unexplained recurrent (more than one), prolonged (>24 hours) episode of severe, diffuse (poorly localized) abdominal pain AND at least TWO of the following:
- Red to brownish urine.
Key exclusion criteria (4 listed)
- Pregnant or breastfeeding women
- type 2 diabetes mellitus
- History of alcohol or drug abuse
- Inability to provide informed consent or comply with protocol
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Autonomic Function TestingAutonomic function test (orthostatic blood pressure and heart rate response to tilt, heart rate response to deep breathing, the Valsalva ratio, and beat-to-beat blood pressure measurements during phases II and IV of the Valsalva maneuver, tilt, and deep breathing). These combined tests provide a measurement of adrenergic, cardiovagal responses. | Diagnostic test | – |
| Genetic TestingGenetic testing: for Acute hepatic porphyria panel - with intent to use Saliva kit | Diagnostic test | – |
| Urine TestingUrine PBG, ALA and porphyrins in a spot urine sample with results normalized to urine creatinine | Diagnostic test | – |
| Blood laboratory TestingTo determine the following laboratory analyses: CBC, CMP, Iron studies (Ferritin and iron studies) | Diagnostic test | – |
Primary outcome
AHP Case ascertainment in POTS patients
Time frame: During the intervention
Evaluating the Prevalence of Acute Hepatic Porphyria in Postural Tachycardia Syndrome
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Sep 2026.
- Results publication: PubMed 10037110Robertson D; New Collective Author. The epidemic of orthostatic tachycardia and orthostatic intolerance. Am J Med Sci. 1999 Feb;317(2):75-7. doi: 10.1097/00000441-199902000-00001. No abstract available.
- Results publication: PubMed 17709712Garland EM, Raj SR, Black BK, Harris PA, Robertson D. The hemodynamic and neurohumoral phenotype of postural tachycardia syndrome. Neurology. 2007 Aug 21;69(8):790-8. doi: 10.1212/01.wnl.0000267663.05398.40.
- Results publication: PubMed 8423877Schondorf R, Low PA. Idiopathic postural orthostatic tachycardia syndrome: an attenuated form of acute pandysautonomia? Neurology. 1993 Jan;43(1):132-7. doi: 10.1212/wnl.43.1_part_1.132.
- Results publication: PubMed 16943900Raj SR. The Postural Tachycardia Syndrome (POTS): pathophysiology, diagnosis & management. Indian Pacing Electrophysiol J. 2006 Apr 1;6(2):84-99.
- Results publication: PubMed 25483980Loavenbruck A, Iturrino J, Singer W, Sletten DM, Low PA, Zinsmeister AR, Bharucha AE. Disturbances of gastrointestinal transit and autonomic functions in postural orthostatic tachycardia syndrome. Neurogastroenterol Motil. 2015 Jan;27(1):92-8. doi: 10.1111/nmo.12480. Epub 2014 Dec 6.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Cyndya Shibao, M.D principal investigator
Vanderbilt University Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Postural Orthostatic Tachycardia Syndrome and Acute Hepatic Porphyria, run by Vanderbilt University Medical Center at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 28 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
AHP Case ascertainment in POTS patients (time frame: During the intervention). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05344599, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Sep 2026.