Recruiting

Vagus Nerve Stimulation

Sponsor:

Indiana University

Code:

NCT06597149

Conditions

Healthy

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Accepted

Interventions

Transcutaneous Auricular Vagus Nerve Stimulation

Sham Procedure (No Stimulation)

Study Details

Brief summary:

The vagus or vagal nerve is a nerve that sends signals from the brain to other parts of the body to control involuntary functionm, including stomach function, and it is important to the regulation of insulin, C-peptide, and glucose levels. The purpose of this study is to evaluate whether electrically stimulating the nerve around the external ear will also stimulate the internal vagus nerve and influence the levels of insulin, C-peptide, and glucose. If it does, investigators hope that this will help innovate treatment of patients with nausea, vomiting, and disordered stomach function, and patients with diabetes.

Conditions

Healthy

Study ID

NCT06597149

Start date

Apr 21, 2025

Status verified date

Sep, 2026

Completion date

May 31, 2027

Anticipated

Primary completion date

May 31, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Healthy Volunteers
  • Aged 18-70
  • Willing to have ECG electrodes placed on their neck and chest areas.
  • Willing to have electrodes placed in the external ear.
  • Willing to have an indwelling catheter placed to avoid multiple sticks for blood draw.

Exclusion Criteria:

  • Unable to provide consent.
  • Diabetes diagnosis per patient report
  • Having known allergies to adhesive on electrode pads or bandages
  • Having gastric motility issues as determined by the PI or clinical coordinator.
  • Taking any medications that may affect gastric motility or cardiac variability, i.e. alpha or beta blockers for hypertension.
  • Pregnant females
  • Those unwilling to have the taVNS device placed in their ear.
  • Those unwilling to consent to a blood draw.
  • Prisoners

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Active Stimulation, then No electrodes

After an initial baseline blood sample is drawn, a TENS unit electrode clip will be placed on the inside of the outer ear and vagal nerve recordings are initiated. After 20 minutes of baseline recording, a second blood sample is drawn, after which, the TENS unit is turned ON for 40 minutes of stimulation. At the end of the stimulation period, a third blood sample is drawn and the TENS device is then turned OFF. After 20 minutes of recovery, a fourth and final sample of blood is drawn. Vagal nerve activity recordings are continued until the final blood sample is drawn.

Subjects will be asked to return for an additional visit during which the TENS unit will not be placed, but the same vagal nerve recordings and blood draws will be obtained.

sham comparator: Sham Stimulation, then No Electrodes

After an initial baseline blood sample is drawn, a TENS unit electrode clip will be placed on the inside of the outer ear, but will not be turned on. Vagal nerve recordings will be initiated. After 20, 60 and 80 minutes, additional blood samples are drawn. Vagal nerve activity recordings are continued until the final blood sample is drawn.

Subjects will be asked to return for an additional visit during which the TENS unit will not be placed, but the same vagal nerve recordings and blood draws will be obtained.

Interventions

Transcutaneous Auricular Vagus Nerve Stimulation

For participants in the active stimulation group, electrical stimuli are delivered continuously for 40 minutes at a pulse width of 300 microseconds, pulse frequency of 25 Hz, and pulse amplitude of 0.5 to 1.5 mA based on the tolerance of the patient. Stimuli current and frequency may be decreased, if necessary, to minimize participant discomfort.

Sham Procedure (No Stimulation)

The TENS device will be placed but not turned on.

Primary outcome measure

  • Change in plasma insulin levels [ Time Frame: Study Days 1 and 2 ]
  • Change in C-peptide levels [ Time Frame: Study Days 1 and 2 ]
  • Change in glucose levels [ Time Frame: Study Days 1 and 2 ]
  • Change in heart rate variability [ Time Frame: Study Days 1 and 2 ]
  • Association between changes in heart rate variability and plasma insulin levels [ Time Frame: Study Days 1 and 2 ]
  • Association between changes in heart rate variability and C-peptide levels [ Time Frame: Study Days 1 and 2 ]
  • Association between changes in heart rate variability and glucose levels [ Time Frame: Study Days 1 and 2 ]

Central Contacts and Locations

Central contacts

Maureen Schilling, BS

3172782064maschi@iu.edu

Locations

Indiana University Hospital

Recruiting

Indianapolis, Indiana, United States, 46202

Contacts

Maureen Schilling, BS

3172782064maschi@iu.edu

Thomas V Nowak, MD

3179484272tvnowak@iu.edu

More Information

Sponsor

Indiana University

Last update posted

Oct 1, 2026

Last verified

Sep, 2026

Keywords

  • Healthy
  • Individual

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-24. This information was provided to ClinicalTrials.gov by Indiana University on 2026-10-01. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.