Short cold sessions to grow and activate brown fat

Investigating the Cellular Heterogeneity of Human Brown Adipose Tissue and Its (Patho)Physiological Regulation

NA · University of Edinburgh · NCT07048405

This study will test whether daily two-hour cold sessions in healthy adults (ages 18–40) change the activity and gene patterns of brown fat, white fat, and muscle.

Quick facts

PhaseNA
Study typeInterventional
Enrollment12 (estimated)
Ages18 Years to 40 Years
SexAll
SponsorUniversity of Edinburgh (other)
Locations1 site (Edinburgh)
Trial IDNCT07048405 on ClinicalTrials.gov

What this trial studies

Healthy adults will undergo baseline warm and cold measurements including energy expenditure, skin and core temperature, and a dynamic whole-body 18F-FDG PET/CT scan. Tissue biopsies (supraclavicular brown adipose tissue, vastus lateralis muscle, and periumbilical subcutaneous white adipose tissue) will be taken before and after a 10-day cold-acclimation protocol consisting of 2 hours per day using water-perfused cooling blankets. The trial will compare PET/CT imaging, physiological measures, and molecular analyses to identify cellular heterogeneity and gene-expression changes in thermogenic tissues. Results will map how repeated short cold exposure remodels tissue composition and transcriptional programs.

Who should consider this trial

Good fit: Ideal participants are healthy adults aged 18–40 with BMI 18.5–25 kg/m2, stable weight, no regular medications, no major medical conditions, and able to undergo PET/CT scans and tissue biopsies.

Not a fit: People with chronic illnesses, outside the age or BMI ranges, who are pregnant or breastfeeding, on regular medications, claustrophobic, or unable to tolerate biopsies or PET/CT scans are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, findings could identify ways to boost brown fat activity and mass that may improve metabolism and lower cardiometabolic risk.

How similar studies have performed: Prior studies have shown intermittent cold increases brown fat activity and mass on 18F-FDG PET/CT, but the detailed cellular and molecular adaptations are largely untested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Aged 18-40 years
* Body mass index 18.5-25 kg/m2
* Weight change of less than 5% in the past 6 months
* No acute or chronic medical conditions
* On no regular medications (other than contraceptives in female participants)
* No claustrophobia
* Alcohol intake ≤14 units/ week
* Screening blood tests within acceptable limits (of no clinical significance)
* Not currently pregnant, lactating or breastfeeding (female participants only)
* Ability to provide informed consent.

Exclusion Criteria:

* Not meeting inclusion criteria
* Contra-indication to PET/CT scan
* Allergy to local anaesthetic

Where this trial is running

Edinburgh

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Brown Adipose Tissue, Cold Exposure, 18F-FDG PET/CT

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.