HealthyICENCT05884177
Inuit and Cold Exposure
An observational study of Healthy, run by Stig Andersen at 1 site in Denmark.
Trial summary
Brown adipose tissue (BAT) produces heat through non-shivering thermogenesis. It is activated by cold exposure, and when activated it utilizes fatty acids and glucose in order to produce heat. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Short-term cold exposure
- How many people
- 25 participants
- Where
- 1 siteDenmark
- Study dates
- 18 Sep 2023to Dec 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Healthy, lean, young Greenlanders and non-Greenlanders living in Denmark
Who may be able to join
- Ability to give informed consent
- Ability to follow written and verbal instructions
Who cannot join
- Pregnancy and breastfeeding
- Alpha- or beta-adrenergic affecting medication.
- Thyroid dysfunction
- Liver or kidney disease
- Treatment for diabetes
- MODY and TBC1D4
Show all 17Show fewer
- Treatment of obesity
- Cardiovascular disease
- Cancer within 3 years
- Mb Renaud
- Hospitalisation for psychiatric disease
- Antipsychotic medication
- Drug abuse within 1-year
- Alcohol abuse
- Plasma glucose > 11 mM
- BMI >35 kg/m2
- Winter swimmer
Trial locations and contacts
1 site in 1 country.
Denmark1 site, 1 recruiting
- Recruiting
Aalborg University Hospital
Aalborg, 9000
Mette MM Jensen, MD, +4597660000, mette.malene@rn.dk
Stig Andersen, MD, PhD, +4597660000, lasa@rn.dk
About this study
Official title: Metabolic Effects of Short-term Cold Exposure Among Greenlanders and Non-Greenlanders
Brown adipose tissue (BAT) produces heat through non-shivering thermogenesis. It is activated by cold exposure, and when activated it utilizes fatty acids and glucose in order to produce heat. The tissue is especially present in newborns, who not yet have gained a layer of insulating fat to protect from heat loss, and not yet have gained much muscle to produce heat through shivering thermogenesis.
It was long thought that BAT mass hereafter would retract. Modern imaging tools have proved that BAT is persistent and active in some adults. The presence and activity of BAT is negatively correlated with obesity and obesity-related metabolic disorders. The tissue retracts with advancing age and increasing BMI, and it is sensitive to environmental factors, such as diet, weather and climate. The key to activating BAT in subjects that have lost it remains elusive.
BAT is activated to produce heat when exposed to cold. Populations that are most cold exposed include people living in the Arctic. It is known that people of Arctic origin such as indigenous Inuit and indigenous Siberians have genetically adapted to and are acclimatized to the cold through several genetic changes, and possibly by upregulating BAT depots and activity. The investigators aim to dig deeper into the activation mechanisms in BAT, by investigating BAT mass and activity in Greenlanders and non-Greenlanders by use of stage-of-the-art modern techniques.
Read the detailed description
Several studies have examined the function of brown adipose tissue (BAT), which is an important source of non-shivering thermogenesis. It has gained attention as a potential target for combating obesity.
BAT has a distinct influence on glucose and triglyceride clearance, and insulin sensitivity, and it has a negative correlation with cardiometabolic risk markers.
BAT activity is correlated with cold temperatures. Observational studies in Greenland are consistent with raised consumption of thyroid hormone and higher thyroid hormone turnover in cold-exposed Inuit compared to Inuit with some and limited cold exposure.
However, these are indirect data that merely suggest the presence of BAT. The presence of active BAT directly illustrated by using an individualized cooling protocol and FDG-PET/CT-scan raises interest in the origin and characterization of intermediate adipose cells (beige adipose tissue) from the white adipose tissue.
Based on the strong correlation between BAT and cardiometabolic health and the evolutionary pressure on Inuit to handle cold environments, the investigators will measure the cold-induced BAT activity and white fat differentiation and assess a connection with genetic and physiological characteristics ot add insight into the biology and regulation of BAT in relation to fat depots in humans.
Participants of Danish and Greenlandic origin will be included for a focus on visualizing brown adipose tissue by use of PET/CT-scans before and after short term cold exposure. Additional sampling includes subcutaneous fat biopsies, blood samples, blood pressure, pulse, temperature of the skin and core, and IRT.
- Conditions
- Healthy
- Being tested
- Short-term cold exposure
- Keywords
- Brown Adipose Tissue
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Short-term cold exposureOther
Short-term cold exposure
| Study group | Role | What they receive |
|---|---|---|
| Greenlanders | Subjects born in Greenland with parents born in Greenland Receives: Other: Short-term cold exposure | |
| non-Greenlanders | Subjects not born in Greenland with parents not born in Greenland Receives: Other: Short-term cold exposure |
What is being measured
The primary outcome is the main question the study is designed to answer.
BAT detection
BAT mass in the cervical-upper thoracic, abdominal, and paravertebral regions at room temperature and following short-term cold exposure. BAT mass on PET/CT scans will be quantified by the degree of glucose uptake: Maximum standard unit value (SUVmax)
Measured: Through study completion, analysis for an average of 1 year
Secondary outcomes (5)
Temperature of the core and at the skin on multiple sites
Temperature of the core and at the skin on multiple sites. Core temperature measured with rectal thermometer. Skin temperatures measured with skin thermometer probes and infrared thermography (IRT).
Measured: Through study completion, analysis for an average of 1 year
Changes in thyroid function
Changes in thyroid function as measured by plasma TT3, TT4 and TSH
Measured: Through study completion, analysis for an average of 1 year
Changes in metabolites
Changes in metabolites: Plasma glucose, acylcarnitine and triglycerides
Measured: Through study completion, analysis for an average of 1 year
Insulin sensitivity
Insulin sensitivity
Measured: Through study completion, analysis for an average of 1 year
Adipose tissue composition
Subcutaneous fat biopsies will be examined in relation to white adipose tissue (WAT) function and presence of beige adipocytes
Measured: Through study completion, analysis for an average of 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jun 2023
- Study start18 Sep 2023 (estimated)
- Primary completionDec 2024 (estimated)
- Study completionDec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 25 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Stig Andersen
- Sponsor type
- University, hospital or other
- Collaborators
- University of Copenhagen, Greenland University
- Responsible party
- Sponsor-investigator, Stig Andersen, Aalborg University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05884177
- Sponsor's protocol ID
- F2023-040
- Acronym
- ICE
- Status last verified
- Aug 2023
- First submitted
- 4 May 2023
- Last updated
- 22 Aug 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Restrictions apply due to limited number of participants
Publications
Motzfeldt Jensen M, Elberling Almasi C, Kjaergaard B, Rasmussen BS, Haunstrup T, Ulrik Thomsen S, Andersen MK, Hansen T, Ellervik C, Scheele C, Jorgensen ME, Andersen S. Cross-over comparative study of cold-induced brown adipose tissue activity in Greenlandic Inuit and Danes: rationale, design, and methodology. Int J Circumpolar Health. 2025 Dec;84(1):2545662. doi: 10.1080/22423982.2025.2545662. Epub 2025 Aug 18.
PubMed 40820950
Study at a glance
From the registry record, last updated by the sponsor on 22 Aug 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Metabolic Effects of Short-term Cold Exposure Among Greenlanders and Non-Greenlanders
- ClinicalTrials.gov ID
- NCT05884177
- Acronym / sponsor ID
- ICE / F2023-040
- Conditions
- Healthy
- Keywords
- Brown Adipose Tissue
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 25 participants (estimated)
- Lead sponsor
- Stig AndersenUniversity, hospital or other
- Collaborators
- University of Copenhagen, Greenland University
- Study start
- 18 Sep 2023 (estimated)
- Primary completion
- Dec 2024 (estimated)
- Study completion
- Dec 2025 (estimated)
- First posted
- 1 Jun 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Brown adipose tissue (BAT) produces heat through non-shivering thermogenesis. It is activated by cold exposure, and when activated it utilizes fatty acids and glucose in order to produce heat. The tissue is especially present in newborns, who not yet have gained a layer of insulating fat to protect from heat loss, and not yet have gained much muscle to produce heat through shivering thermogenesis.
It was long thought that BAT mass hereafter would retract. Modern imaging tools have proved that BAT is persistent and active in some adults. The presence and activity of BAT is negatively correlated with obesity and obesity-related metabolic disorders. The tissue retracts with advancing age and increasing BMI, and it is sensitive to environmental factors, such as diet, weather and climate. The key to activating BAT in subjects that have lost it remains elusive.
BAT is activated to produce heat when exposed to cold. Populations that are most cold exposed include people living in the Arctic. It is known that people of Arctic origin such as indigenous Inuit and indigenous Siberians have genetically adapted to and are acclimatized to the cold through several genetic changes, and possibly by upregulating BAT depots and activity. The investigators aim to dig deeper into the activation mechanisms in BAT, by investigating BAT mass and activity in Greenlanders and non-Greenlanders by use of stage-of-the-art modern techniques.
Detailed description
Several studies have examined the function of brown adipose tissue (BAT), which is an important source of non-shivering thermogenesis. It has gained attention as a potential target for combating obesity.
BAT has a distinct influence on glucose and triglyceride clearance, and insulin sensitivity, and it has a negative correlation with cardiometabolic risk markers.
BAT activity is correlated with cold temperatures. Observational studies in Greenland are consistent with raised consumption of thyroid hormone and higher thyroid hormone turnover in cold-exposed Inuit compared to Inuit with some and limited cold exposure.
However, these are indirect data that merely suggest the presence of BAT. The presence of active BAT directly illustrated by using an individualized cooling protocol and FDG-PET/CT-scan raises interest in the origin and characterization of intermediate adipose cells (beige adipose tissue) from the white adipose tissue.
Based on the strong correlation between BAT and cardiometabolic health and the evolutionary pressure on Inuit to handle cold environments, the investigators will measure the cold-induced BAT activity and white fat differentiation and assess a connection with genetic and physiological characteristics ot add insight into the biology and regulation of BAT in relation to fat depots in humans.
Participants of Danish and Greenlandic origin will be included for a focus on visualizing brown adipose tissue by use of PET/CT-scans before and after short term cold exposure. Additional sampling includes subcutaneous fat biopsies, blood samples, blood pressure, pulse, temperature of the skin and core, and IRT.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Greenlanders | – | Other: Short-term cold exposureSubjects born in Greenland with parents born in Greenland |
| non-Greenlanders | – | Other: Short-term cold exposureSubjects not born in Greenland with parents not born in Greenland |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Healthy, lean, young Greenlanders and non-Greenlanders living in Denmark
Key inclusion criteria (2 listed)
- Ability to give informed consent
- Ability to follow written and verbal instructions
Key exclusion criteria (17 listed)
- Pregnancy and breastfeeding
- Alpha- or beta-adrenergic affecting medication.
- Thyroid dysfunction
- Liver or kidney disease
- Treatment for diabetes
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Short-term cold exposureShort-term cold exposure | Other | Greenlanders, non-Greenlanders |
Primary outcome
BAT detection
Time frame: Through study completion, analysis for an average of 1 year
BAT mass in the cervical-upper thoracic, abdominal, and paravertebral regions at room temperature and following short-term cold exposure. BAT mass on PET/CT scans will be quantified by the degree of glucose uptake: Maximum standard unit value (SUVmax)
5 secondary outcomes
Temperature of the core and at the skin on multiple sites
Time frame: Through study completion, analysis for an average of 1 year
Changes in thyroid function
Time frame: Through study completion, analysis for an average of 1 year
Changes in metabolites
Time frame: Through study completion, analysis for an average of 1 year
Insulin sensitivity
Time frame: Through study completion, analysis for an average of 1 year
Adipose tissue composition
Time frame: Through study completion, analysis for an average of 1 year
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Aug 2023.
- Derived from this study: PubMed 40820950Motzfeldt Jensen M, Elberling Almasi C, Kjaergaard B, Rasmussen BS, Haunstrup T, Ulrik Thomsen S, Andersen MK, Hansen T, Ellervik C, Scheele C, Jorgensen ME, Andersen S. Cross-over comparative study of cold-induced brown adipose tissue activity in Greenlandic Inuit and Danes: rationale, design, and methodology. Int J Circumpolar Health. 2025 Dec;84(1):2545662. doi: 10.1080/22423982.2025.2545662. Epub 2025 Aug 18.
- Individual participant dataSharing planned: No. Restrictions apply due to limited number of participants
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Healthy, run by Stig Andersen at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 22 Aug 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Mette MM Jensen, MD (+4597660000, mette.malene@rn.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
BAT detection (time frame: Through study completion, analysis for an average of 1 year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05884177, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Aug 2023.