NCT05468151

Cold Acclimation As a Modulator of Brown Adipose Tissue Function in Adults with Obesity

• Status: Active Not Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 45 (estimated)
• Sponsor: Turku University Hospital · Other Government
• Sex: All
• Age: 18 Years – 45 Years
• Healthy volunteers: Accepted

Summary

This study will investigate the effects of at least 12 weeks of weekly cold water immersions (water temperature 18ºC) on BAT perfusion in individuals with obesity. BAT oxygen uptake and tissue perfusion will be measured using 15O-O2 and 15O-H2O PET-CT, at room temperature and after cold exposure. In addition, BAT glucose uptake will be measured using 18F-FDG after 2 hours of cold exposure and BAT NEFA uptake will be analyzed using 18F-FTHA at room temperature. To understrand the metabolic effects of BAT activation in individuals with obesity and how the cold water immersions affect the BAT perfusion in humans is critical for the development of new strategies to treat obesity and its comorbidities.

Detailed description

Obesity is a highly prevalent non-communicable disease that effects more than 20% of the population worldwide. Brown adipose tissue (BAT) has an unique ability to dissipate the energy as heat and it has been associated with metabolic benefits. Additionally, BAT has been found to be more active in young, healthy, lean individuals and to be inactive in subjects with obesity. Some studies have shown that repeated cold acclimation can enhance BAT metabolism, which is accompanied by metabolic benefits, such as improvements in insulin sensitivity. In this study we will investigate whether 12 weeks or more of cold acclimation are sufficient to improve BAT perfusion at room temperature and after 2 hours of cold exposure, and to stimulate glucose uptake (measured using 18F-FDG) in BAT after 2 hours of cold exposure. Furthermore, changes in BAT NEFA uptake will be analyzed using 18F-FTHA at room temperature. The metabolic effects of the cold acclimation protocol will be evaluated by changes in classical cardiovascular risk markers (lipid profile, glucose and insulin) after 12 weeks. Two different control groups will be included: one will include lean, healthy participants while the other will include subjects with obesity. Both groups will undergo the BAT PET/scans protocol at room temperature and after cold exposure to investigate BAT perfusion, BAT glucose uptake and BAT NEFA uptake. The volunteers with obesity will also undergo a second evaluation 12 weeks after baseline measurements.

Conditions

• Obesity

Interventions

Type	Name	Description
OTHER	Cold acclimation	The cold water immersions will last 30-60 minutes per day and the volunteers will undergo 2-3 cold immersions per week.
OTHER	Intervention Control group - volunteers with obesity	Participants with obesity in the control group will undergo PET/CT scans at baseline and 12 weeks after the first scan.
OTHER	Acute cold exposure	All participants (lean and with obesity) will undergo PET/scans after 2 hours of cold exposure to investigate BAT perfusion and BAT glucose uptake.

Timeline

• Start date: 2022-07-25
• Primary completion: 2024-12-20
• Completion: 2026-07-01
• First posted: 2022-07-21
• Last updated: 2025-03-04

Locations

1 site across 1 country: Finland