Health TrialsbyHealthPanel

Sympathetic Overactivity in Post-traumatic Stress Disorder

ConditionsPost-traumatic Stress DisorderPrehypertension
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-65
SponsorEmory University

About this trial

Post-traumatic stress disorder (PTSD) is a highly prevalent anxiety disorder that is associated with an increased risk of cardiovascular (CV) disease and hypertension. One potential mechanism is overactivation of the sympathetic nervous system (SNS), both at rest and particularly during stress. This study will evaluate whether 8 weeks of daily DGB therapy or transcutaneous vagus nerve stimulation (tVNS) therapy improves SNS activity at rest and during stress.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

prehypertensive and normotensive veterans with PTSD, and prehypertensive and normotensive veterans without PTSD (controls)

Disqualifiers

heart or vascular disease

illicit drug use within the last 6 months

excessive alcohol use (>2 drinks per day)

pregnancy

Trial design

Design model

Parallel

Treatments tested in this trial

  • Device-Guided Breathing (DGB)

    Device

    The RESPeRATE device will be used for 15 minutes of device-guided breathing daily for 8 weeks. The participant places the elastic belt with a respiration sensor around the upper abdomen, and wears earbuds for audio feedback. The device monitors the breathing rate, calculates inspiration and expiration times, and generates a personalized melody of two distinct ascending and descending tones for inhalation versus exhalation. Users effortlessly entrain their breathing pattern with the tones, and the device gradually guides the user to a prolonged expiration time and slower respiratory rate (to \< 10 breaths/minute). The device automatically stores usage data, allowing for quantification of adherence and performance.

  • Sham DGB

    Device

    The sham device is identical to the DGB device, except it does not guide respiratory rates to slow down and instead maintains a rate of 14 breaths per minute. The sham device is used for 15 minutes per day for 8 weeks.

  • Transcutaneous Vagal Nerve Stimulation (tVNS)

    Device

    tVNS is a noninvasive method that involves placing a device over the skin overlying the vagus nerve on the neck. The device delivers mild electrical stimulation, using transcutaneous electrical nerve stimulation (TENS) unit. The stimulation is increased until there is a vibration and slight muscle contraction in the lower face or neck. Then the stimulation is delivered for 2 minutes on the left side of the neck, and on the right side of the neck, for a total of 4 minutes. The tVNS device is used twice daily for 8 weeks.

  • Sham tVNS

    Device

    Sham stimulation is delivered using a device that is identical to the gammaCore device but is programed to deliver a lower frequency that can be felt by the participant but does not actually stimulate the vagus nerve. The sham device is used twice daily for 8 weeks.

Treatment groups

120 Participants
are divided into 4 treatment groups
Group A: Device-guided Breathing (DGB)Experimental treatment 1 intervention
Group B: Sham DGBSham comparator 1 intervention
Group C: Transcutaneous Vagal Nerve Stimulation (tVNS)Experimental treatment 1 intervention
Group D: Sham tVNSSham comparator 1 intervention

Trial outcomes

Primary outcomes

1

Change in Muscle Sympathetic Nerve Activity (MSNA) Burst Frequency at Rest

MSNA is assessed with microneurography where a tungsten microelectrode inserted in the nerve records sympathetic nerve activity.

Time frame
Baseline, Week 8
2

Change in Baroreflex Sensitivity (BRS) at Rest

Arterial baroreflex sensitivity (BRS) will be tested using pharmacologic manipulation of blood pressure at rest. BRS is assessed by measuring changes in MSNA and heart rate during arterial blood pressure changes induced by nitroprusside and phenylephrine.

Time frame
Baseline, Week 8
3

Change in MSNA Burst Frequency While Under Mental Stress

Mental stress will be induced by having participants complete mental arithmetic and with a combat virtual reality clip.

Time frame
Baseline, Week 8
4

Change in BRS While Under Mental Stress

Mental stress will be induced by having participants complete mental arithmetic and with a combat virtual reality clip. Arterial baroreflex sensitivity (BRS) will be tested using pharmacologic manipulation of blood pressure at rest and during mental stress.

Time frame
Baseline, Week 8

Secondary outcomes

1

Endothelial Function

Endothelial Function will be measured using peripheral arterial tonometry.

Time frame
Baseline, Week 8
2

Vascular Stiffness

Vascular stiffness will be measured noninvasively using pulse wave analysis and pulse wave velocity.

Time frame
Baseline, Week 8

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Emory University

Lead sponsor

US Department of Veterans Affairs

Collaborator

Source ClinicalTrials.gov
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