Noninvasive Neuromodulation of the Prefrontal Cortex in Subjects With Obesity
- Conditions
- Obesity
- Interventions
- Device: Active transcranial direct current stimulation (tDCS)Other: Hypocaloric dietOther: Sham transcranial direct current stimulation (tDCS)
- Registration Number
- NCT02953353
- Lead Sponsor
- University of Sao Paulo
- Brief Summary
The overall goal of this proposal is to evaluate the efficacy of transcranial direct current stimulation (tDCS), a noninvasive neuromodulation technique, to facilitate weight loss and weight loss maintenance in obesity. This is a novel clinical research study that examines the therapeutic potential of an innovative biomedical treatment for weight loss.
- Detailed Description
The hypothesis is that tDCS will successfully engage prefrontal-related neurobehavioral cognitive control systems, resulting in decreased eating disinhibition and therefore facilitation of weight loss and weight loss maintenance. To test this hypothesis, a 6-month randomized, sham-controlled, double-blind, intervention study was designed. Subjects will undergo an intervention with the following components/phases:
1. Phase 1 - Target engagement (one session) The purpose of this phase is to examine whether tDCS can reach the brain target, the dorsolateral prefrontal cortex, and influence performance in a neuropsychology tests that depends on the activity of this region. Results from this component of the study will provide evidence for target engagement. Genomic DNA will be extracted from whole blood for sequencing of Catechol-O-methyltransferase (COMT) and brain-derived neurotrophic factor (BDNF) polymorphism genotypes.
2. Phase 2 - tDCS alone (two weeks) During this phase participants will receive daily tDCS sessions over the course of two weeks (Monday to Friday; total=10 sessions). The purpose of this phase is to examine the effect of modulating the activity of the prefrontal cortex with tDCS on body weight under baseline/weight stable conditions. Also analyse changes in appetite and eating behavior.
3. Phase 3 - tDCS plus hypocaloric diet (two weeks). During this phase participants will undergo a hypocaloric diet intervention aimed at achieving a 5% body weight reduction at 3 months. The diet will be individualized on the basis of physical activity levels, age for each participant. This intervention will be be conducted at an inpatient, well-controlled setting to guarantee adherence to the diet. Here the diet intervention will be administered in combination with tDCS. tDCS will be applied every other day (Monday, Wednesday, Friday) over the course of these two weeks. The purpose of this component is to examine acute changes in weight associated with tDCS in combination with the diet. Also analyse changes in appetite and eating behavior.
4. Phase 4 - Follow up (6 months). During this phase (outpatient) changes in body weight over time will be assessed to evaluate weight maintenance. Subjects will be asked to come back to the laboratory at 1, 3 and 6 months. Also analyse changes in appetite and eating behavior.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Female
- Target Recruitment
- 38
- Women with obesity (BMI 30-35 kg/m2), with stable weight over the previous 3 months.
- pregnancy
- diabetes
- acute and chronic kidney disease
- pancreatitis
- any active psychiatric or neurological condition at the time of joining the study
- intake of centrally-acting medications that could interfere with tDCS effects
- anemia (Hgb <12 g/dl)
- any other significant medical condition
- contraindications for tDCS, which includes damaged skin at the site of stimulation, any electrically sensitive or metallic device and history of epilepsy
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Active group Active transcranial direct current stimulation (tDCS) Active transcranial direct current stimulation (tDCS) and hypocaloric diet. Active group Hypocaloric diet Active transcranial direct current stimulation (tDCS) and hypocaloric diet. Control group Sham transcranial direct current stimulation (tDCS) Sham transcranial direct current stimulation (tDCS) and hypocaloric diet. Control group Hypocaloric diet Sham transcranial direct current stimulation (tDCS) and hypocaloric diet.
- Primary Outcome Measures
Name Time Method Body weight 6 months The primary outcome will be change in body weight after two weeks intervention (tDCS alone) versus baseline (day 1), the change in body weight between the beginning and the end of the inpatient period (tDCS plus hypocaloric diet), and the change in body weight throughout follow-up (6 months), i.e. between the end of the tDCS intervention (end of the inpatient phase) and the end of the study.
- Secondary Outcome Measures
Name Time Method Cognitive performance in a food modified working memory test 2 weeks The investigators will compare accuracy and reaction times before and after the 2 weeks with tDCS only. To evaluate working memory performance an N-back task will be used.
Eating behavior questionnaire 6 months The investigators will analyse changes in eating behavior during the different phases of the study: phase 1 (target engagement), phase 2 (tDCS-only effect), phase 3 (tDCS plus diet effect), phase 4 (follow-up) using the three-factor eating and food craving questionnaires.
Appetite visual analogue scale 6 months The investigators will analyse changes in appetite during the different phases of the study: phase 1 (target engagement), phase 2 (tDCS-only effect), phase 3 (tDCS plus diet effect), phase 4 (follow-up) using the visual analogue scale.
Trial Locations
- Locations (3)
Human Nutrition Research Center on Aging, Tufts University
🇺🇸Boston, Massachusetts, United States
Beth Israel Deaconess Medical Center, Harvard Medical School
🇺🇸Boston, Massachusetts, United States
Clinical Hospital of Ribeirão Preto
🇧🇷Ribeirão Preto, São Paulo, Brazil