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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
A study on energy-burning effect of brown fat in humans
Scientific title
Brown Adipose Tissue Thermogenesis in Healthy Humans
Secondary ID [1] 285380 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 293113 0
Diabetes 293114 0
Condition category
Condition code
Metabolic and Endocrine 293384 293384 0 0
Metabolic disorders
Diet and Nutrition 293385 293385 0 0
Metabolic and Endocrine 293613 293613 0 0

Study type
Description of intervention(s) / exposure
This is an interventional study examining the relation between brown fat activity and glucose/energy homeostasis.
It involves two half-day studies (4 hours), 1 week apart, measuring brown fat quantity, energy burning rate and hormone levels. Volunteers will be exposed to i) mild cold (between 12 to 19 degree celcius - a personalised temperature in which volunteers feel cool but are no shivering) and also ii) be given 75 g of glucose as a drink to examine effect of cold and glucose on brown fat activity.
Intervention code [1] 290293 0
Other interventions
Comparator / control treatment
Glucose/energy metabolism is compared between individuals with different brown fat quantity and activity. No comparison will be made between different temperatures or before/after food.
Control group

Primary outcome [1] 293217 0
Glucose tolerance by standard oral glucose tolerance test.
Timepoint [1] 293217 0
Conducted at time 0, 60 and 120 minutes at each visit
Secondary outcome [1] 310606 0
Adipokine profile by serum assay
Timepoint [1] 310606 0
At time 0, 60 and 120 minutes at each visit
Secondary outcome [2] 314840 0
Brown fat quantity assessed by PET scanning
Timepoint [2] 314840 0
At time 120 minutes of each visit
Secondary outcome [3] 314841 0
Energy burning rate by indirect calorimetry
Timepoint [3] 314841 0
At time 0, 60 and 120 minutes of each visit

Key inclusion criteria
Healthy volunteers
Minimum age
18 Years
Maximum age
40 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Body mass index > 30 kg/m2.
Significant cardiac, respiratory, thyroid, renal and/or hepatic dysfunction

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
i) Exposure to mild cold temperature during PET/CT scanning

ii) oral glucose drink (75g glucose)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
All volunteers are exposed to same mild cold and glucose drink.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Single group
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Unpaired t-tests and ANOVA between variables.
Our pilot data revealed an increase in BAT activity by 9+/-6% (mean +/- standard deviation) following exposure to mild cold condition. Using a two-tailed paired t-test, with a=0.05, and 1-beta =0.8 (power), calculated sample size is N=10. However we are comparing the difference in energy metabolism between brown fat positive and negative individuals. We thus refine sample size calculation based on the more conservative difference in energy expenditure. A total of 14 volunteers will be required to detect a decrease in ~7+/-6% of BAT-related metabolic activity at a two-sided 0.05 significance level with a probability of 80%. Given potential differences between men and women, and to ensure attainment of a final sample size of 14, we have increased the accrual ceiling and will recruit a total of 30 subjects (50% men). This decision takes into consideration potential screening failure.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 3008 0
St Vincent's Hospital (Darlinghurst) - Darlinghurst

Funding & Sponsors
Funding source category [1] 289990 0
Name [1] 289990 0
Diabetes Australia Research Trust (DART) grant
Address [1] 289990 0
Level 1, 101 Northbourne Avenue TURNER ACT 2612

GPO Box 3156 CANBERRA ACT 2601
Country [1] 289990 0
Primary sponsor type
Other Collaborative groups
Garvan Institute of Medical Research
384 Victoria Street
Sydney, NSW 2010
Secondary sponsor category [1] 288675 0
Name [1] 288675 0
St Vincent's Hospital, Sydney
Address [1] 288675 0
380 Victoria Street
NSW 2010
Country [1] 288675 0

Ethics approval
Ethics application status
Ethics committee name [1] 291698 0
St Vincent's Hospital HREC
Ethics committee address [1] 291698 0
Level 6 deLacy Building
St Vincent's Research Office
St Vincent's Hospital
380 Victoria Street
Darlinghurst NSW 2010
Ethics committee country [1] 291698 0
Date submitted for ethics approval [1] 291698 0
Approval date [1] 291698 0
Ethics approval number [1] 291698 0

Brief summary
Obesity is a major health issue worldwide. Despite global research efforts, effective treatments for obesity are limited. There are two kinds of fat in the body: white fat and brown fat. White fat functions mainly as an energy-storing organ and in excess results in obesity and complications such as diabetes and high blood pressure. Brown fat on the other hand releases the energy stored in fat as heat. It protects small animals and newborn human infants from cold temperatures.

New imaging techniques have revealed brown fat to be present in significant amount in adult humans. Using special metabolic imaging, called PET scanning, brown fat is shown to be more abundant in lean individuals with lower blood glucose levels, suggesting that brown fat may regulate energy balance and metabolism.

In animals, cold temperature and food both stimulate brown fat, resulting in release of energy. This is called adaptive thermogenesis, and it represents a considerable portion of total daily energy expenditure. Whether brown fat controls adaptive thermogenesis in humans is unclear. This is clinically relevant because if brown fat regulates adaptive thermogenesis in humans, strategies can be developed to stimulate brown fat to increase energy expenditure, which may be a new method to help attain weight control and develop treatment of obesity-related disorders.

In order to determine the physiologic significance of brown fat activation, we designed a study investigating the effects of cold exposure and food on brown fat in humans.

We hypothesize that adaptive thermogenesis in adult humans can be activated by cold or food, and the extent depends on individual brown fat abundance. Brown fat activity can be increased by cold stimulation, which could result in beneficial metabolic changes in the body.

The aims of the current project are to:
1) determine relationship between brown fat and adaptive thermogenesis
2) investigate the underlying hormonal mechanisms and significance of brown fat activation

Brown fat abundance will first be measured by PET scanning during mild cold condition. Volunteers then undergo metabolic and hormonal testing at standard ambient temperature (24 degrees). A parallel study will examine brown fat biopsies obtained during elective neck surgery to investigate mechanisms underlying brown fat activation.

Significance: Based on its role in energy homeostasis and protection against obesity in animals, brown fat is likely to have a similar role in adult humans. Determining the contribution of brown fat to energy metabolism may lead to novel treatment strategies of obesity.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 51606 0
Dr Paul Lee
Address 51606 0
Garvan Institute of Medical Research
384 Victoria Street
NSW 2010
Country 51606 0
Phone 51606 0
+61 2 9295 8416
Fax 51606 0
+61 2 9295 8481
Email 51606 0
Contact person for public queries
Name 51607 0
Dr Paul Lee
Address 51607 0
Garvan Institute of Medical Research
384 Victoria Street
NSW 2010
Country 51607 0
Phone 51607 0
+61 2 9295 8416
Fax 51607 0
+61 2 9295 8481
Email 51607 0
Contact person for scientific queries
Name 51608 0
Dr Paul Lee
Address 51608 0
Garvan Institute of Medical Research
384 Victoria Street
NSW 2010
Country 51608 0
Phone 51608 0
+61 2 9295 8416
Fax 51608 0
+61 2 9295 8481
Email 51608 0

No information has been provided regarding IPD availability
Summary results
No Results