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Gastrointestinal Symptoms in Postural Orthostatic Tachycardia Syndrome (POTS-GUT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03263819
Recruitment Status : Active, not recruiting
First Posted : August 28, 2017
Last Update Posted : September 2, 2020
Information provided by (Responsible Party):
Cyndya Shibao, Vanderbilt University Medical Center

Brief Summary:

Patients with POTS experience significant gastrointestinal symptoms. Current evidence suggesting that abnormal post-ganglionic sympathetic function could play a role in the pathophysiology of these GI abnormalities. Sympathetic fiber regulate motor and the postprandial GI peptides secretion.

The focus of the present proposal is to determine glucose homeostasis, GI motility, and their association with GI and cardiovascular symptoms in POTS patients versus healthy controls. Furthermore, we will determine differences in these outcomes in POTS patients with and without evidence of postganglionic sympathetic fiber neuropathy.

As a long-term goal, this study can lead us to understand the pathophysiology of common co-morbidities in patients with POTS to provide new treatment approaches and prevention strategies.

Condition or disease Intervention/treatment
Postural Tachycardia Syndrome Diagnostic Test: Oral glucose tolerance test

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Study Type : Observational
Estimated Enrollment : 48 participants
Observational Model: Case-Control
Time Perspective: Prospective
Actual Study Start Date : June 20, 2017
Estimated Primary Completion Date : December 31, 2020
Estimated Study Completion Date : December 31, 2020

Group/Cohort Intervention/treatment
patients with postural orthostatic tachycardia syndrome diagnosis.
Diagnostic Test: Oral glucose tolerance test
75 grams of glucose

Healthy controls
Patients with Postural orthostatic tachycardia syndrome who has peripheral neuropathy
Diagnostic Test: Oral glucose tolerance test
75 grams of glucose

Primary Outcome Measures :
  1. Gastrointestinal hormones plasma levels after oral glucose tolerance test [ Time Frame: 0-120 minutes. ]
    The plasma levels of GI peptides (GLP-1, GLP-2, PPY, glucagon, C-peptide, insulin) and their pattern of secretion after ingestion of 75 g glucose.

Secondary Outcome Measures :
  1. Gastric emptying after oral glucose [ Time Frame: 0-120 minutes. ]
    Gastric emptying time will be measured by acetaminophen absorption test after ingestion of 75 grams glucose.

  2. Gastrointestinal symptoms [ Time Frame: 0-120 minutes ]
    The gastrointestinal symptoms will be evaluated by questionnaire after ingestion of 75 grams glucose.

  3. POTS related symptoms [ Time Frame: 0-120 minutes. ]
    Symptoms related to postural orthostatic tachycardia symptoms will be evaluated by specific questionnaire after ingestion of 75 grams glucose.

Biospecimen Retention:   Samples With DNA
Whole blood will be retain for DNA extraction.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   Female
Sampling Method:   Non-Probability Sample
Study Population
The participants with POTS and "complete autonomic failure" will be recruited from patients referred to the Vanderbilt University Autonomic Dysfunction Center. Additional patients will be recruited from the POTS registry in ResearchMatch, and information about the study will be posted on websites associated with POTS support groups. Healthy volunteers will be recruited from a population of previous participants in autonomic studies, through the database, Subject Locator, and through advertising and emails around the Vanderbilt community.

Inclusion Criteria:

  • 18-60 years old
  • Postural Tachycardia Syndrome: Heart rate increase >30 bpm from supine within 10 min of standing, in the absence of orthostatic hypotension (>20/10 mmHg fall in blood pressure), with chronic symptoms (> 6 months), and in the absence of other acute cause of orthostatic tachycardia.
  • Able and willing to provide informed consent
  • Female premenopausal subjects must utilize adequate birth control and willingness to undergo serum beta-hCG (human chorionic gonadotropin) testing

Exclusion Criteria:

  • Use of acetaminophen or acetaminophen-related drugs (over-the-counter) in the 24 hours prior to the study.
  • Hypertension (>150 mmHg systolic and >100 mmHg diastolic) based on history or findings on screening.
  • Orthostatic hypotension (consistent decrease in BP >20/10 mmHg with 10 min stand)
  • Pregnancy
  • History of type 1 or type 2 diabetes mellitus
  • Cardiovascular disease, such as myocardial infarction within 6 months, angina pectoris, significant arrhythmia (sinus tachycardia is not excluded), deep vein thrombosis, pulmonary embolism
  • History of serious neurologic disease
  • Impaired hepatic function (aspartate amino transaminase and/or alanine amino transaminase >1.5 x upper limit of normal range)
  • Impaired renal function (serum creatinine >1.5 mg/dL)
  • Hematocrit <28%
  • Any underlying or acute disease requiring regular medication that could possibly pose a threat to the subject or make implementation of the protocol or interpretation of the study results difficult
  • Inability to comply with the protocol

Healthy control subjects

Defined as subjects without any significant past medical history, non-smokers, and on no chronic medications at the time of the study. Healthy control subjects will be age- and BMI-matched to the POTS patients.

Positive control

Patients with complete autonomic neuropathy (pure autonomic failure) will be enrolled as positive control. This condition is defined as complete autonomic failure based on AFT (autonomic function test) and norepinephrine plasma levels less than 100 pg/ml.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03263819

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United States, Tennessee
Vanderbilt University Medical Center
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University Medical Center
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Principal Investigator: cyndya shibao Vanderbilt University Medical Center
Postural Tachycardia Syndrome Information Page: National Institute of Neurological Disorders and Stroke (NINDS) [Internet]. [cited 2016 Aug 15]. Available from:
Dysautonomia International: Postural Orthostatic Tachycardia Syndrome [Internet]. [cited 2016 Aug 15]. Available from:

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Responsible Party: Cyndya Shibao, Assistant Professor, Vanderbilt University Medical Center Identifier: NCT03263819    
Other Study ID Numbers: 170052
First Posted: August 28, 2017    Key Record Dates
Last Update Posted: September 2, 2020
Last Verified: September 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Cyndya Shibao, Vanderbilt University Medical Center:
gastrointestinal hormones
Postural Orthostatic Tachycardia Syndrome
Additional relevant MeSH terms:
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Postural Orthostatic Tachycardia Syndrome
Pathologic Processes
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Cardiac Conduction System Disease
Orthostatic Intolerance
Primary Dysautonomias
Autonomic Nervous System Diseases
Nervous System Diseases