Orthostatic Intolerance After Bariatric Surgery

Stopped early · Phase 1 · Has a placebo group

Conditions studied: Orthostatic Intolerance

In brief

More than 78 million adults in the U.S. are obese. Bariatric surgery is the only modality that results in sustained weight loss along with reversal of diabetes mellitus, and a decrease in cardiovascular events. Obesity is associated with increased sympathetic nervous system (SNS) activity that contributes to blood pressure regulation; sympathetic vasoconstrictor activity is maximally activated upon standing and is fundamental for the maintenance of orthostatic tolerance. After bariatric surgery, there is a significant and sustained reduction in SNS activity at three and six months after the procedure, which is related to weight loss. Recently, multiple retrospective studies have reported an orthostatic intolerance (OI) syndrome after bariatric surgery characterized by chronic pre-syncopal symptoms, syncope and orthostatic hypotension. In the Vanderbilt University Medical Center bariatric surgical center, 741 post-bariatric surgery patients reported OI symptoms, 98 (13.2%) of these patients, progressed to chronic OI and in17 cases, the OI was so disabling that patients initiated treatment with pressor agents. More than 50% of OI cases in the cohort developed the condition during a weight-stable period. Hence, investigators propose the novel hypothesis that after bariatric surgery, the persistent reduction in SNS activity contributes to impaired orthostatic tolerance, which is independent of weight loss.

Key facts

Study ID

NCT03808740

Run by

Vanderbilt University Medical Center

People needed

10

Starts

2018-07-01

Expected to finish

2021-05-31

Last updated by the study team

2024-09-27

Who can join

Age: 18 and older, up to 60. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• Obese subjects that will undergo bariatric surgery or medical weight loss.
• Age 18-60 years
• BMI >35 kg/m2
• Weight < 400 lbs

You may not qualify if…

• Diabetes type 1
• Use of an alpha blockers, clonidine, beta-blockers.
• Pregnancy or breast-feeding. Women of childbearing potential will be required to have undergone tubal ligation or to be using an oral contraceptive or barrier methods of birth control.
• The use of any strong CYP2D6 inhibitor (e.g., fluoxetine, paroxetine, quinidine, tipranavir).
• Use of selective NET inhibitors.
• Use of monoamine oxidase inhibitors.
• Cardiovascular disease such as myocardial infarction within six months prior to the study, presence of angina pectoris, significant arrhythmia, congestive heart failure (left ventricular hypertrophy acceptable), deep vein thrombosis, pulmonary embolism, second or third degree heart block, mitral valve stenosis, aortic stenosis or hypertrophic cardiomyopathy
• History of serious neurologic disease such as cerebral hemorrhage, stroke, or transient ischemic attack
• Hematocrit < 34%
• Any underlying or acute disease requiring regular medication which could possibly pose a threat to the subject or make implementation of the protocol or interpretation of the study results difficult
• Mental conditions rendering a subject unable to understand the nature, scope and possible consequences of the study
• Inability to comply with the protocol, e.g., uncooperative attitude, inability to return for follow-up visits, unlikelihood of completing the study, and investigator discretion

Where it is running

• Cyndya Shibao — Nashville, Tennessee, United States

Full record on ClinicalTrials.gov

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