CANBAT: CB1 Receptors in Human Brown Adipose Tissue
Study Details
Study Description
Brief Summary
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Detailed 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.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: [18F]FMPEP-d2 in warm conditions PET scan is performed using PET radiotracer [18F]FMPEP-d2 in standard room temperature conditions. |
Other: [18F]FMPEP-d2
PET radiotracer used in imaging
|
| Other: [18F]FMPEP-d2 in cold conditions PET scan is performed using PET radiotracer [18F]FMPEP-d2 during controlled cold exposure. |
Other: Cold exposure
Controlled cold exposure is performed before and during PET scan
Other: [18F]FMPEP-d2
PET radiotracer used in imaging
|
| Other: [18F]FDG in cold conditions PET scan is performed using PET radiotracer [18F]FDG during controlled cold exposure. |
Other: Cold exposure
Controlled cold exposure is performed before and during PET scan
Other: [18F]FDG
PET radiotracer used in imaging
|
Outcome Measures
Primary Outcome Measures
- CB1 density of brown adipose tissue acquired with PET [within one study day]
PET imaging is used to quantify CB1 receptors in tissues
Secondary Outcome Measures
- Glucose uptake of brown adipose tissue acquired with PET [within one study day]
PET imaging is used to quantify glucose uptake in tissues
Eligibility Criteria
Criteria
Inclusion Criteria:
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Healthy volunteer
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Group 1: BMI 20-26 kg/m2, Group2: BMI 27-40 kg/m2
Exclusion Criteria:
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BMI < 20 kg/m2or BMI > 40 kg/m2
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Any chronic disease that could affect the study outcome, including medicated type 2 diabetes
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Mental disorder or poor compliance
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Eating disorder or excessive use of alcohol, tobacco smoking or drug use
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Past dose of radiation
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Presence of any ferromagnetic objects that would make MR imaging contraindicated
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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
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Turku PET Centre (Turku University Hospital) | Turku | Finland | 20521 |
Sponsors and Collaborators
- Turku University Hospital
Investigators
- Principal Investigator: Pirjo Nuutila, M.D., Ph.D., Turku PET Centre (Turku University Hospital)
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 42/2014