CB1 Receptors in Human Brown Adipose Tissue (CANBAT)

Turku University Hospital (TYKS)

Status: Completed

Conditions: Obesity

Treatments: Other: [18F]FMPEP-d2; Other: Cold exposure; Other: [18F]FDG

Study type: Interventional

Funder types: Other

Identifiers

NCT02941172

42/2014

Details and patient eligibility

About

This study investigates cannabinoid CB1 receptors in human brown adipose tissue (BAT) and other tissues using positron emission tomography (PET) imaging. Subjects will be scanned in room temperature conditions and during controlled cold exposure, and the density of CB1 receptors in BAT and other tissues will be quantified. The investigators hypothesize, that cannabinoid signaling is increased in cold conditions, when BAT is metabolically active.

Understanding the mechanisms of BAT activation and the role of endocannabinoids in humans is important and beneficial in fighting against the epidemic of obesity and diabetes.

Full description

Endocannabinoids have an important role in regulating energy balance and metabolism. Cannabinoid 1 receptors (CB1) are found in several tissues such as brown adipose tissue (BAT). Endocannabinoids and CB1 receptors participate in the control of lipid and glucose metabolism, and blockage of CB1 receptors has been found to improve metabolic factors linked to obesity and cardiovascular disease, making CB1 antagonists potential drugs against obesity and diabetes.

In this study the investigators use a PET radiotracer [18F]FMPEP-d2, which binds to CB1 receptors in vivo, to quantify the CB1 receptor density in BAT, white adipose tissue, muscle and the brain. This study is done once in warm conditions and once during controlled cold exposure. To verify whether the subject has metabolically active BAT, an additional PET scan with the radiotracer [18F]FDG is performed.

Enrollment: 18 patients

Sex: Male

Ages: 18 to 60 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy volunteer
• Group 1: BMI 20-26 kg/m2, Group2: BMI 27-40 kg/m2

Exclusion criteria

• BMI < 20 kg/m2or BMI > 40 kg/m2
• Any chronic disease that could affect the study outcome, including medicated type 2 diabetes
• Mental disorder or poor compliance
• Eating disorder or excessive use of alcohol, tobacco smoking or drug use
• Past dose of radiation
• Presence of any ferromagnetic objects that would make MR imaging contraindicated
• Any other condition that in the opinion of the investigator could create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of study results

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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18 participants in 3 patient groups

[18F]FMPEP-d2 in warm conditions

Other group

Description:

PET scan is performed using PET radiotracer \[18F\]FMPEP-d2 in standard room temperature conditions.

Treatment:

Other: [18F]FMPEP-d2

[18F]FMPEP-d2 in cold conditions

Other group

Description:

PET scan is performed using PET radiotracer \[18F\]FMPEP-d2 during controlled cold exposure.

Treatment:

Other: [18F]FMPEP-d2

Other: Cold exposure

[18F]FDG in cold conditions

Other group

Description:

PET scan is performed using PET radiotracer \[18F\]FDG during controlled cold exposure.

Treatment:

Other: [18F]FDG

Other: Cold exposure