Brown Adipose Tissue Activity and Age

Study Overview
=================
Brief Summary
-----------------
In this study the investigators aim to investigate whether the sympathetic stimulation of BAT, as assessed with a 123I-metaiodobenzylguanidine single-photon emission computed tomography computed tomography scan, differs between young and elderly subjects, as an explanation for the diminished metabolic brown adipose tissue activity in the elderly. The investigators hypothesis is that sympathetic nervous system activity in the elderly is diminished as compared to their younger counterparts as an explanation for the diminished metabolic brown adipose tissue activity in the elderly.

Detailed Description
-----------------
The sympathetic nervous system is the primary activator of Brown Adipose Tissue. Elderly are known to have less metabolically active brown adipose tissue as compared to their younger counterparts. The reason for this diminished metabolic brown adipose tissue activity is unknown. However, a lower sympathetic nervous system activation to brown adipose tissue in the elderly might explain a diminished metabolic brown adipose tissue. Therefore, in this study, both the sympathetic nervous system activation to brown adipose tissue and the metabolic activity will be measured in young and older subjects. sympathetic nervous system activity will be measured using 123I-metaiodobenzylguanidine single-photon emission computed tomography computed tomography scans, metabolic activity will be measured using 18F- fluorodeoxyglucose positron emission tomography CT scans.

Official Title
-----------------
Brown Adipose Tissue Activity Young and Older Individuals

Conditions
-----------------
Obesity, Ageing

Intervention / Treatment
-----------------
* Other: 18-FDG PET CT scan and 123I-MIBG SPECT scan


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Male Caucasian origin Subjects should be able and willing to give informed consent 18-65 years old BMI range of 19-27 kg/m2 Exclusion Criteria: Renal failure (creatinine>135mmol/l) Daily use of prescription medication Prior participation in a research protocol involving radiation exposure in the last 2 years

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Young males<br>Healthy, Lean, Caucasian, Young males | Other: 18-FDG PET CT scan and 123I-MIBG SPECT scan<br> <br> |
| Old males<br>Healthy, Lean, Caucasian, Older males | Other: 18-FDG PET CT scan and 123I-MIBG SPECT scan<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in sympathetic stimulation to BAT between young and older individuals |  | Participants will be followed for a mean duration of 2 weeks (the maximal time period between the two scans) The outcome measurements will be assessed when the last subject has been scanned approximately one year after starting the trial. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in correlation between sympathetic stimulation of BAT as assessed with 123I-MIBG SPECT scans and metabolic BAT activity as assessed with 18F-Fluorodeoxyglucose(FDG)- positron emission tomography(PET)-CT scan in young and older individuals | The difference in correlation between sympathetic stimulation of BAT as assessed with a MIBG SPECT-CT scan, and BAT activity itself as assessed with 18F-FDG-PET-CT, between young and elderly subjects | Participants will be followed for a mean duration of 2 weeks (the maximal time period between the two scans) The outcome measurements will be assessed when the last subject has been scanned approximately one year after starting the trial. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Brown adipose Tissue, Ageing, Sympathetic Nervous Stimulation, Obesity