Inuit and Cold Exposure

NCT05884177 | Unknown

• 1 other identifier: F2023-040
• Study Type: observational
• Target: 25
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Healthy

Keywords

Brown Adipose Tissue

Outcome Measures

Primary Outcomes (1)

• 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)

  Through study completion, analysis for an average of 1 year

Secondary Outcomes (5)

• Temperature of the core and at the skin on multiple sites

  Through study completion, analysis for an average of 1 year

• Changes in thyroid function

  Through study completion, analysis for an average of 1 year

• Changes in metabolites

  Through study completion, analysis for an average of 1 year

• Insulin sensitivity

  Through study completion, analysis for an average of 1 year

• Adipose tissue composition

  Through study completion, analysis for an average of 1 year

Study Arms (2)

Greenlanders

Subjects born in Greenland with parents born in Greenland

Other: Short-term cold exposure

non-Greenlanders

Subjects not born in Greenland with parents not born in Greenland

Other: Short-term cold exposure

Interventions

Short-term cold exposure OTHER

Short-term cold exposure

Greenlanders; non-Greenlanders

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Healthy, lean, young Greenlanders and non-Greenlanders living in Denmark

You may qualify if:

• Ability to give informed consent
• Ability to follow written and verbal instructions

You may not qualify if:

• Pregnancy and breastfeeding
• Alpha- or beta-adrenergic affecting medication.
• Thyroid dysfunction
• Liver or kidney disease
• Treatment for diabetes
• MODY and TBC1D4
• 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

Sponsors & Collaborators

• Stig Andersen: lead
• University of Copenhagen: collaborator
• Greenland University: collaborator

Study Sites (1)

Aalborg University Hospital

Aalborg, 9000, Denmark

RECRUITING

Related Publications (1)

• Motzfeldt Jensen M, Almasi CE, Kjaergaard B, Rasmussen BS, Andersen MK, Schubert M, Hansen T, Ellervik C, Scheele C, Jorgensen ME, Andersen S. Brown Adipose Tissue and Metabolic Markers Differ Between Greenlanders and Danes with Cold-Activation. J Clin Endocrinol Metab. 2025 Nov 17:dgaf615. doi: 10.1210/clinem/dgaf615. Online ahead of print.

  PMID: 41243523 DERIVED

Central Study Contacts

Mette MM Jensen, MD

CONTACT

+4597660000; mette.malene@rn.dk

Stig Andersen, MD, PhD

CONTACT

+4597660000; lasa@rn.dk

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Professor, Department Head

Study Record Dates

• First Submitted: May 4, 2023
• First Posted: June 1, 2023
• Study Start: September 18, 2023
• Primary Completion: December 1, 2024
• Study Completion: December 1, 2025
• Last Updated: August 22, 2023

Record last verified: 2023-08

Data Sharing

• IPD Sharing: Will not share

Locations

DK (1)