Activation of Cervical and Upper Thoracic Brown Adipose Tissue in Humans Via Beta-adrenergic Stimulation

Study Overview
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Brief Summary
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In this study the investigators aim to quantitate the extent of cervical and upper thoracic brown adipose tissue (BAT) activation in lean and obese humans via positron emission tomography-computed tomography (PET-CT) in response to the non-specific beta adrenergic receptor (AR) agonist ephedrine. The investigators hypothesise that this pharmacological adrenergic stimulus will result in activation of BAT in these participants, and that this activation will be reduced in obese patients. This study will provide important preliminary information with respect to allowing the investigators to progress with longer trials with specific beta 3 AR agonists.

Official Title
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Activation of Cervical and Upper Thoracic Brown Adipose Tissue in Humans Via Beta-adrenergic Stimulation

Conditions
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Obesity

Intervention / Treatment
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* Drug: ephedrine hydrochloride
* Drug: ephedrine hydrochloride


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy group Males aged 20 - 40 years Free of overt coronary disease (on history, medical examination and ECG) Fasting plasma glucose < 6.1 mmol/L and 2 hour OGTT glucose < 7.8 mmol/L Unmedicated No major illness BMI 18 - 25 Inclusion Criteria: obese group Males aged 20 - 40 years Free of overt coronary disease (on history, medical examination and ECG) Unmedicated No major illness BMI 30+ Weight < 100 kg Height < 185 cm The inclusion criteria (Obese participants) of body weight less than  100 kg is implemented as the PET-CT scanner to be utilised (protocol described subsequently) has a limited patient volume. Therefore to fit within the criteria of BMI > 30, only patients of height  183 cm or less can be recruited, and inclusion of borderline participants will be discussed with co-investigators from the Alfred Hospital Nuclear Medicine Department. Exclusion Criteria: healthy group Unable to give informed consent Smokers Lactose intolerance Exclusion Criteria: obese group Unable to give informed consent Smokers Lactose intolerance Participant in research projects involving ionising radiation within the past 5 years claustrophobia

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Adrenergic agonist<br> | Drug: ephedrine hydrochloride<br>* single oral dose, 1mg/kg body weight<br>Drug: ephedrine hydrochloride<br>* single dose of 1 mg/kg body weight<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| BAT activity via PET-CT |  | Baseline and 3 weeks |