Dopamine in Orthostatic Tolerance

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: NCT00748228
Recruitment Status : Terminated (This study is being replaced by another protocol.)
First Posted : September 8, 2008
Last Update Posted : June 15, 2015
Information provided by (Responsible Party):
Emily M. Garland, Vanderbilt University

Brief Summary:
One goal of this study is to determine whether people with different amounts of dopamine-beta-hydroxylase (DBH) have different responses to events that affect blood pressure and heart rate. We will also study whether increasing dietary salt improves symptoms during upright posture. Finally, we will examine whether the dietary sodium level influences serum DBH activity and whether DBH level influences the response to sodium. DBH levels and the function of the sympathetic or involuntary nervous system will be assessed in normal volunteers and in patients with postural tachycardia syndrome (POTS).

Condition or disease Intervention/treatment Phase
Postural Tachycardia Syndrome Dietary Supplement: dietary sodium Not Applicable

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 22 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Supportive Care
Official Title: Dopamine in Orthostatic Tolerance
Study Start Date : November 2004
Actual Primary Completion Date : July 2012
Actual Study Completion Date : July 2012

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Sodium

Arm Intervention/treatment
Experimental: A
10 mEq/day dietary sodium
Dietary Supplement: dietary sodium
10 mEq/day

Experimental: B
150 mEq/day dietary sodium
Dietary Supplement: dietary sodium
150 mEq/day dietary sodium

Experimental: C
300 mEq/day dietary sodium
Dietary Supplement: dietary sodium
300 mEq/day

Primary Outcome Measures :
  1. plasma dopamine-beta-hydroxylase [ Time Frame: at enrollment and after tests ]
  2. plasma dopamine [ Time Frame: after tests ]

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Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Upright plasma norepinephrine > 600 pg/ml, or
  • An increase in heart rate of > 30 beats per minute upon standing, and
  • Withdrawal of all medications for at least 3 days, and
  • No associated medical illness, and
  • Age 18 - 60 years old.

Exclusion Criteria:

  • Older than 60 years of age
  • Routinely taking medications affecting the autonomic nervous system
  • Any chronic illness (cardiac, pulmonary, endocrine, gastrointestinal, rheumatologic) other than POTS
  • Anemia (Hct < 30)
  • Women of childbearing age who are pregnant or nursing
  • Unable to give informed consent

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): NCT00748228

United States, Tennessee
Vanderbilt University
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University
Principal Investigator: Emily M Garland, PhD Vanderbilt University

Additional Information:
Responsible Party: Emily M. Garland, Research Assistant Professor, Vanderbilt University Identifier: NCT00748228     History of Changes
Other Study ID Numbers: 040769
First Posted: September 8, 2008    Key Record Dates
Last Update Posted: June 15, 2015
Last Verified: June 2015

Additional relevant MeSH terms:
Postural Orthostatic Tachycardia Syndrome
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Orthostatic Intolerance
Primary Dysautonomias
Autonomic Nervous System Diseases
Nervous System Diseases
Cardiotonic Agents
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Dopamine Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Protective Agents