Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) for Food Craving in Obese Individuals.

Summary

Background: Obesity is one of the most important diseases around the globe; with a continuous increase and public health concern. Current treatments present some limitations. Craving is a symptom usually noticeable and has been described as a "strong desire or urge to use", especially with foods. The vagus nerve and its relations to the neurocircuitry of the reward system play essential roles in food intake regulation and this can be done transcutaneously trough the auricular branch of the vagus nerve (taVNS). Based on the neurobiology of food craving and on the initial data on taVNS demonstrating safety and efficacy in open-label and randomized sham controlled trials, the investigators propose the first randomized, sham controlled, triple-blind trial on taVNS for food craving in obesity.

Methods: This will be a two-arm, triple-blinded, randomized controlled trial with 54 subjects with food craving assigned to either: 1) a 10-session treatment protocol of real taVNS, or 2) a 10-session treatment protocol of sham taVNS, besides qualitative electroencephalogram (qEEG) and heart rate variability (HRV). Participants will be evaluated for primary outcome measures (Food Craving Questionnaire - State \[FCQ-S\] and Food Craving Questionnaire - Trait \[FCQ-T\]) before and after intervention, with a follow-up visit of 30 days after the end of treatment. A comparison between sham and active groups will be performed in three occasions \[baseline (T1), at the end of the stimulation protocol (T2) and 30 days after the last day of stimulation (T3)\].

Discussion: Given the epidemiological situation and economic and social burdens, the possibility of modulating the reward system neurocircuitry trough the vagus nerve with an easy-to-use, low-cost, safe and potential at-home use could represent a breakthrough in treating obesity. The investigators hypothesized that food craving in obese individuals would decrease at least 50%, as well as their intake of high fat, high sugar and processed food, commonly described as palatable foods. Beyond that, the investigators expect that these individuals would improve anxiety symptoms.

Conditions

• Obesity
• Craving

Interventions

DEVICE

Active-taVNS

Stimulation will be performed using the Neurodyn II (Ibramed) equipment approved by the national regulatory agency (ANVISA). The following parameters will be used: 120 Hz (hertz) of frequency, 250 μs of pulse duration and 12 milliamperes of intensity for a continuous stimulation for 30 minutes. This intensity corresponds to a non-painful mild paresthesia without muscle contraction previously described and evaluated. The 25 cm² (centimeters) electrodes will be positioned over the retroauricular area. A total of 10 sessions (one session per day during 10 week-days) will be performed. Every session will be followed by an interview with a trained psychiatrist to evaluate possible adverse effects and guarantee safety issues regarding the study itself.

DEVICE

Sham-taVNS

Regarding sham protocol, the device will be turned off after 60 seconds of stimulation without the knowledge of the patient. After this initial period, the referred paresthesia seems to diminish due to nerve accommodation.

Sponsors & Collaborators

• Federal University of São Paulo

  lead OTHER

Principal Investigators

• Ruth B Grigolon, Master · Federal University of São Paulo

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2017-10-31

Primary Completion

2018-10-31

Completion

2019-10-31

Countries

• Brazil

Study Locations