Clinical trial NCT04420650: Improving Insulin Sensitivity by Non-invasive Brain Stimulation
Official title: Improving Insulin Sensitivity by Non-invasive Brain Stimulation
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Insulin Resistance
Transcranial Direct Current Stimulation
Obesity
Diabetes
Magnetic Resonance Imaging
Lead sponsor: University Hospital Tuebingen
Sponsor class: OTHER
Collaborators: name: German Center for Diabetes Research
First posted: 2020-06-09
Enrollment: 44
Sex: ALL
Minimum age (years): 20
Maximum age (years): 66
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: Efforts in curing and preventing obesity and type 2 diabetes (T2D) have been elusive thus far. One reason for that is the lack of understanding of the role of the brain in the development and treatment of the disease. In recent studies, the hypothalamus was identified as part of a brain network including higher cognitive regions that is particularly vulnerable to insulin resistance. Furthermore, the central insulin response in this network predicted food craving and hunger. In this project, transcranial direct current stimulation (tDCS) is implemented as a tool to stimulate brain networks. The investigators hypothesize that stimulating the hypothalamus-cognitive network will enhance insulin sensitivity and reduce food intake, food craving and hunger. Furthermore, the project will provide the unique opportunity to investigate novel mechanisms of insulin resistance in participants who have been extensively metabolically characterized.

Detailed description: Objectives The overarching aim of the study is to stimulate the hypothalamus-cognitive brain network to improve insulin sensitivity and eating behavior.

Specific Objectives

1. Implement tDCS stimulation compared to sham stimulation in overweight and obese adults to assess the impact on eating behavior, cognition and metabolism.
2. Evaluate whether 3-day non-invasive brain stimulation of the hypothalamus-cognitive network has a causal effect on metabolism.
3. Evaluate whether 3-day non-invasive brain stimulation has a significant effect on brain functional connectivity and diffusion parameters.

Eligibility criteria: Inclusion Criteria:

* Body mass index (BMI) between 25.5 and 39.5 kg/m2
* Age between 20 to 66 years of age
* Waist circumference ≥ 80 cm for women, ≥ 94 cm for men

Exclusion Criteria:

* Insufficient knowledge of the German language
* Persons who cannot legally give consent
* Pregnancy or lactation
* History of severe mental or somatic disorders including neurological diseases (incl. epileptic seizures)
* Taking psychotropic drugs
* Previous bariatric surgery
* Acute infection within the last 4 weeks
* Hemoglobin values less than 12g/dl for women, less than 14 g/dl for men
* Current participation in a lifestyle intervention study or a pharmaceutical study
* Contradictions to a MRI measurement (e.g. metal implants)

Primary outcomes:
measure: Peripheral insulin sensitivity
timeFrame: 1 day after last intervention tDCS day
measure: Caloric intake (kcal)
timeFrame: 1 hour directly after tDCS stimulation
measure: Change in subjective feeling of hunger and food craving
timeFrame: 5 minutes before tDCS stimulation, 5 minutes after tDCS stimulation and 5 minutes after buffet
Secondary outcomes:
measure: Performance during stop-signal task
timeFrame: task is performed during 25-minutes tDCS stimulation
measure: Tastiness and healthiness rating of food stimuli
timeFrame: task is performed immediatly after buffet
measure: Food choice
timeFrame: task is performed immediatly after buffet
measure: Functional connectivity
timeFrame: 10 minutes functional MRI measurement performed before and after three day tDCS stimulation
measure: Diffusion-weighted imaging
timeFrame: 15 minutes MRI measurement performed before and after three day tDCS stimulation
Other outcomes:
Locations:
city: Tübingen
country: Germany
facility: University Clinic Tübingen
Study officials:
affiliation: Univeristy of Tübingen, Germany
name: Stephanie Kullmann, PhD
role: PRINCIPAL_INVESTIGATOR
References: