ObesityREBASNCT06874309
Non-invasive Brain Stimulation to Prepare the Patient for Bariatric Surgery (REBAS)
A study testing home-based tDCS stimulation and Bariatric surgery in people with Obesity, run by Masaryk University at 2 sites in Czechia.
Trial summary
Obesity is a chronic metabolic condition characterized by excessive accumulation of body fat, which triggers physiological mechanisms that increase the risk of a wide range of health problems. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Obesity
- What is being tested?
- home-based tDCS stimulation and Bariatric surgery
- Type of treatment
- Medical device, Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 65 participants
- Where
- 2 sitesCzechia
- Study dates
- 1 May 2024to 31 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Subjects with severe or morbid obesity (determined by BMI > 35 or 40 kg/m2, respectively) eligible for BS treatment in compliance with the current guidelines
- Subjects who meet reduced control over eating behavior (disinhibition) criteria in the Eating Habits Questionnaire
Who cannot join
- Subjects unable to provide informed consent and those unable to understand and cooperate with study-related procedures (based on the physician's discretion)
- Subjects with a personal history of ischemic heart disease, myocardial infarction, stroke, heart failure, and atrial fibrillation
- Subjects who have already undergone BS treatment in the past
- Pregnant subjects or subjects that plan on becoming pregnant during the study.
- Subjects deemed unsuitable for the study based on expert evaluation (e.g., by a physician or neuropsychologist) will be excluded.
- Subjects with dreadlocks (problematic for the EEG)
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Sylvie Kropáčová, Dr. contact
Czechia2 sites, 2 recruiting
- Recruiting
Saint Anne's University Hospital
Brno, Czechia, 60200
Jana Jarešová, +420705 629 051, jana.jaresova@fnusa.cz
- Recruiting
Central European Institute of Technology Masaryk University
Brno, Czechia, 62500
Petra Holštajn Zemánková, +420776722029, petra.zemankova@mail.muni.cz
Sylvie Kropáčová, sylvie.kropacova@ceitec.muni.cz
About this study
Official title: Non-invasive Brain Stimulation to Prepare the Patient for Bariatric Surgery
Obesity is a chronic metabolic condition characterized by excessive accumulation of body fat, which triggers physiological mechanisms that increase the risk of a wide range of health problems. The most effective treatment for severe obesity is metabolic-bariatric surgery, which can lead to a 15-20% weight reduction, significantly lowering the risks of illness and death. However, the success of this surgery can be threatened by poor eating habits after the procedure. The main goal of this study is to enhance the long-term effectiveness of bariatric surgery by combining it with non-invasive brain stimulation (tDCS) targeting inhibitory centers before the operation. Additionally, the investigators aim to comprehensively monitor patients before and after surgery, focusing on investigating changes in brain function associated with the achieved weight loss.
Read the detailed description
Obesity, defined as a body mass index (BMI) above 30 kg/m² or through other body composition measurements like waist circumference or body fat percentage, is a major risk factor for cardiovascular, neurological, and oncological diseases. It is one of the leading causes of mortality in both men and women. The prevalence of obesity is increasing globally, particularly among younger populations, surpassing undernutrition and posing significant health and socio-economic challenges.
Excess fat accumulation, a hallmark of obesity, impacts the structure and function of nearly all organ systems. This occurs through both physical mechanisms, such as fat deposition around organs, and functional mechanisms, including chronic low-grade inflammation, insulin resistance, dyslipidemia, and altered hormone production and regulation by adipose tissue.
While various therapies have been developed to address the negative effects of obesity on body structure and function, early interventions like lifestyle changes and pharmacotherapy have shown only mild and often temporary weight reduction. These approaches frequently lead to cyclical weight changes, which have been linked to increased cardiovascular risk.
Bariatric surgery has emerged as the most effective treatment for severe obesity, delivering significant and long-lasting weight reduction compared to lifestyle modifications. While lifestyle interventions typically achieve a weight loss of 5-10%, bariatric surgery can result in reductions of 15-20%. However, a notable challenge is the risk of failure, primarily due to noncompliant eating behaviors after surgery. Approximately 40% of individuals with extreme obesity are at high risk of experiencing suboptimal outcomes following bariatric surgery.
To address this issue, our project aims to improve the sustainability of bariatric surgery outcomes by incorporating neuromodulation before the procedure. Specifically, the investigators propose using transcranial direct current stimulation (tDCS) to enhance prefrontal inhibitory control by targeting the left dorsolateral prefrontal cortex (lDLPFC). This home-based, non-invasive brain stimulation method seeks to improve behavioral regulation, potentially reducing the likelihood of postoperative complications related to eating habits.
Additionally, researchers aim to identify neural, cognitive, and behavioral predictors of successful bariatric surgery outcomes. By examining these factors, investigators plan to optimize treatment strategies, ensuring more effective and sustainable results for individuals undergoing bariatric surgery.
- Conditions
- Obesity
- Being tested
- home-based tDCS stimulation, home-based tDCS stimulation - sham, Bariatric surgery
- Keywords
- bariatric surgery, obesity, brain stimulation, tDCS, cognitive control, impulsivity, eating behavior
- Medical subject headings
- Obesity, Impulsive Behavior, Feeding Behavior
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
home-based tDCS stimulationDevice
stimulation parameters: 20 sessions of tDCS over lDLPFC (anode over F3, based on the 10:20 system, and cathode over the right supraorbital area), 2 mA intensity, 20 min duration (30 s fade in/fade out)
home-based tDCS stimulation - shamDevice
20 sessions of tDCS over lDLPFC (anode over F3, based on the 10:20 system, and cathode over the right supraorbital area), the electric current will flow for only 15 s, with similar fade in/fade out, at the beginning and at the end of 20 min, to mimic the subjective sensations that occur during active tDCS.
Bariatric surgeryProcedure or surgery
The operation itself is not a study-related procedure and thus the indicated patients would undergo the surgery regardless of their participation in this study. The operating surgeons will perform either Roux-en-Y or gastric sleeve resection.
| Study group | Role | What they receive |
|---|---|---|
| active tDCS stimulation | Experimental | Participants in this arm will be stimulated for 4 weeks during weekdays leading to 20 sessions of tDCS over lDLPFC. Receives: Device: home-based tDCS stimulation; Procedure: Bariatric surgery |
| sham tDCS stimulation | Sham comparator | In this arm, sham stimulation will be applied for 4 weeks during weekdays leading to 20 sessions of tDCS over lDLPFC. Receives: Device: home-based tDCS stimulation - sham; Procedure: Bariatric surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cognitive impulse control measured via food-modified Go/No-Go task
The cognitive task is used to assess response inhibition, particularly in the context of food-related stimuli. It is a variation of the standard Go/No-Go task, where participants must respond quickly to "Go" stimuli (low-calorie item) while withholding responses to "No-Go" stimuli (high-calorie item). Researchers analyze reaction times, accuracy, and commission errors (responses to No-Go stimuli) to evaluate impulse control.
Measured: Baseline, 1 month and 6 months.
Secondary outcomes (4)
Brain activation related to cognitive control assessed using a multichannel EEG system
The investigators will evaluate brain activity in response to food-modified Go/No-Go stimuli and during rest, using Time-Frequency Analysis, focusing on theta and beta power.
Measured: Baseline, 1 month and 6 months.
Body bioimpedance analysis measured with the InBody 720 device
Patients, wearing light clothing and standing barefoot with their legs slightly apart, will hold the device's sensors. Within seconds, the device calculates parameters such as total body water, fat mass, muscle mass, and segmental composition.
Measured: Baseline, 1 month and 6 months.
Food craving of patients assessed using Food Craving Questionnaire - Trait
The questionnaire has 21 items with a response scale 1-6, higher score means stronger cravings.
Measured: Baseline, 1 month and 6 months.
Eating habits of patients assessed using the Three-Factor Eating Questionnaire
The Questionnaire has 51 items in total, 36 items ask for true/false judgment, and 15 items are scored on a 4-point Likert-type scale, each item scores either 0 or 1 point, the minimum score for factors Cognitive Restraint, Disinhibition, and Hunger is 0-0-0, the possible maximum score is 21-16-14.
Measured: Baseline, 1 month and 6 months.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Mar 2025
- Study start1 May 2024
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 65 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Masaryk University
- Sponsor type
- University, hospital or other
- Collaborators
- St. Anne's University Hospital Brno, Czech Republic
- Responsible party
- Sponsor
- Investigators
- Irena Rektorová, Prof., Principal investigator, Cetral European Institute of Technology
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06874309
- Sponsor's protocol ID
- NW24-04-00392
- Acronym
- REBAS
- Status last verified
- Mar 2025
- First submitted
- 19 Dec 2024
- Last updated
- 13 Mar 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 13 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Non-invasive Brain Stimulation to Prepare the Patient for Bariatric Surgery
- ClinicalTrials.gov ID
- NCT06874309
- Acronym / sponsor ID
- REBAS / NW24-04-00392
- Conditions
- Obesity
- Keywords
- bariatric surgery, obesity, brain stimulation, tDCS, cognitive control, impulsivity, eating behavior
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 65 participants (estimated)
- Lead sponsor
- Masaryk UniversityUniversity, hospital or other
- Collaborators
- St. Anne's University Hospital Brno, Czech Republic
- Study start
- 1 May 2024 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 13 Mar 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Obesity is a chronic metabolic condition characterized by excessive accumulation of body fat, which triggers physiological mechanisms that increase the risk of a wide range of health problems. The most effective treatment for severe obesity is metabolic-bariatric surgery, which can lead to a 15-20% weight reduction, significantly lowering the risks of illness and death. However, the success of this surgery can be threatened by poor eating habits after the procedure. The main goal of this study is to enhance the long-term effectiveness of bariatric surgery by combining it with non-invasive brain stimulation (tDCS) targeting inhibitory centers before the operation. Additionally, the investigators aim to comprehensively monitor patients before and after surgery, focusing on investigating changes in brain function associated with the achieved weight loss.
Detailed description
Obesity, defined as a body mass index (BMI) above 30 kg/m² or through other body composition measurements like waist circumference or body fat percentage, is a major risk factor for cardiovascular, neurological, and oncological diseases. It is one of the leading causes of mortality in both men and women. The prevalence of obesity is increasing globally, particularly among younger populations, surpassing undernutrition and posing significant health and socio-economic challenges.
Excess fat accumulation, a hallmark of obesity, impacts the structure and function of nearly all organ systems. This occurs through both physical mechanisms, such as fat deposition around organs, and functional mechanisms, including chronic low-grade inflammation, insulin resistance, dyslipidemia, and altered hormone production and regulation by adipose tissue.
While various therapies have been developed to address the negative effects of obesity on body structure and function, early interventions like lifestyle changes and pharmacotherapy have shown only mild and often temporary weight reduction. These approaches frequently lead to cyclical weight changes, which have been linked to increased cardiovascular risk.
Bariatric surgery has emerged as the most effective treatment for severe obesity, delivering significant and long-lasting weight reduction compared to lifestyle modifications. While lifestyle interventions typically achieve a weight loss of 5-10%, bariatric surgery can result in reductions of 15-20%. However, a notable challenge is the risk of failure, primarily due to noncompliant eating behaviors after surgery. Approximately 40% of individuals with extreme obesity are at high risk of experiencing suboptimal outcomes following bariatric surgery.
To address this issue, our project aims to improve the sustainability of bariatric surgery outcomes by incorporating neuromodulation before the procedure. Specifically, the investigators propose using transcranial direct current stimulation (tDCS) to enhance prefrontal inhibitory control by targeting the left dorsolateral prefrontal cortex (lDLPFC). This home-based, non-invasive brain stimulation method seeks to improve behavioral regulation, potentially reducing the likelihood of postoperative complications related to eating habits.
Additionally, researchers aim to identify neural, cognitive, and behavioral predictors of successful bariatric surgery outcomes. By examining these factors, investigators plan to optimize treatment strategies, ensuring more effective and sustainable results for individuals undergoing bariatric surgery.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| active tDCS stimulation | Experimental | Device: home-based tDCS stimulation, Procedure: Bariatric surgeryParticipants in this arm will be stimulated for 4 weeks during weekdays leading to 20 sessions of tDCS over lDLPFC. |
| sham tDCS stimulation | Sham comparator | Device: home-based tDCS stimulation - sham, Procedure: Bariatric surgeryIn this arm, sham stimulation will be applied for 4 weeks during weekdays leading to 20 sessions of tDCS over lDLPFC. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Subjects with severe or morbid obesity (determined by BMI > 35 or 40 kg/m2, respectively) eligible for BS treatment in compliance with the current guidelines
- Subjects who meet reduced control over eating behavior (disinhibition) criteria in the Eating Habits Questionnaire
Key exclusion criteria (6 listed)
- Subjects unable to provide informed consent and those unable to understand and cooperate with study-related procedures (based on the physician's discretion)
- Subjects with a personal history of ischemic heart disease, myocardial infarction, stroke, heart failure, and atrial fibrillation
- Subjects who have already undergone BS treatment in the past
- Pregnant subjects or subjects that plan on becoming pregnant during the study.
- Subjects deemed unsuitable for the study based on expert evaluation (e.g., by a physician or neuropsychologist) will be excluded.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| home-based tDCS stimulationstimulation parameters: 20 sessions of tDCS over lDLPFC (anode over F3, based on the 10:20 system, and cathode over the right supraorbital area), 2 mA intensity, 20 min duration (30 s fade in/fade out) | Device | active tDCS stimulation |
| home-based tDCS stimulation - sham20 sessions of tDCS over lDLPFC (anode over F3, based on the 10:20 system, and cathode over the right supraorbital area), the electric current will flow for only 15 s, with similar fade in/fade out, at the beginning and at the end of 20 min, to mimic the subjective sensations that occur during active tDCS. | Device | sham tDCS stimulation |
| Bariatric surgeryThe operation itself is not a study-related procedure and thus the indicated patients would undergo the surgery regardless of their participation in this study. The operating surgeons will perform either Roux-en-Y or gastric sleeve resection. | Procedure or surgery | active tDCS stimulation, sham tDCS stimulation |
Primary outcome
Cognitive impulse control measured via food-modified Go/No-Go task
Time frame: Baseline, 1 month and 6 months.
The cognitive task is used to assess response inhibition, particularly in the context of food-related stimuli. It is a variation of the standard Go/No-Go task, where participants must respond quickly to "Go" stimuli (low-calorie item) while withholding responses to "No-Go" stimuli (high-calorie item). Researchers analyze reaction times, accuracy, and commission errors (responses to No-Go stimuli) to evaluate impulse control.
4 secondary outcomes
Brain activation related to cognitive control assessed using a multichannel EEG system
Time frame: Baseline, 1 month and 6 months.
Body bioimpedance analysis measured with the InBody 720 device
Time frame: Baseline, 1 month and 6 months.
Food craving of patients assessed using Food Craving Questionnaire - Trait
Time frame: Baseline, 1 month and 6 months.
Eating habits of patients assessed using the Three-Factor Eating Questionnaire
Time frame: Baseline, 1 month and 6 months.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Mar 2025.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Sylvie Kropáčová, Dr. contact
Irena Rektorová, Prof. principal investigator
Cetral European Institute of Technology
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing home-based tDCS stimulation and Bariatric surgery in people with Obesity, run by Masaryk University at 2 sites in Czechia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Mar 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Czechia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Petra Holštajn Zemánková, Dr. (+420 776 722 029, petra.zemankova@mail.muni.cz), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cognitive impulse control measured via food-modified Go/No-Go task (time frame: Baseline, 1 month and 6 months.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Mar 2025.