Caffeine's effect on cold-activated brown fat
Effect of Caffeine on Cold-stimulated Brown Adipose Tissue Activity
This test looks at whether taking 200 mg of caffeine before a mild cold exposure increases brown fat activity in healthy adults.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 12 (estimated) |
| Ages | 18 Years to 40 Years |
| Sex | All |
| Sponsor | University Hospital, Basel, Switzerland Academic / other |
| Drugs / interventions | radiation |
| Locations | 1 site (Basel) |
| Trial ID | NCT06978777 on ClinicalTrials.gov |
What this trial studies
This randomized, double-blind, placebo-controlled crossover trial enrolls healthy volunteers who complete a screening visit and two main visits in random order, receiving 200 mg caffeine or placebo before mild cold exposure. During each visit resting energy expenditure is measured by indirect calorimetry at warm baseline and after gradual cooling using wearable cooling sleeves that lower surface temperature without causing shivering. Brown adipose tissue activity is imaged with 18F-FDG PET/CT performed 30 minutes after injection of 75 MBq of tracer. The design compares within-subject differences in metabolic rate and PET signal after caffeine versus placebo to probe the role of adenosine A2A receptor antagonism in cold-stimulated BAT activation.
Who should consider this trial
Good fit: Ideal candidates are healthy, normal-weight adults (BMI 18.5–25) who consume moderate amounts of caffeine (about 1–3 cups of coffee daily), can tolerate mild cold exposure, and show at least a 5% increase in energy expenditure with cold.
Not a fit: People with obesity or uncontrolled cardiometabolic disease, those with hypertension, cardiac arrhythmias, smokers, pregnant individuals, people with caffeine hypersensitivity, or those unable to tolerate mild cold are unlikely to benefit or be eligible.
Why it matters
Potential benefit: If successful, this could identify a simple, low-cost way to boost brown fat thermogenesis that may inform new approaches for metabolic disorders.
How similar studies have performed: Cold exposure reliably activates human BAT in prior work and preclinical data implicate adenosine A2A receptors, but randomized human data testing caffeine as an A2A antagonist to boost BAT are limited and exploratory.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * BMI 18.5 to 25 kg/m2 * Able to give informed consent as documented by signature * Moderate caffeine consumption (1 to 3 cups of coffee per day) * Increase of EE in response to mild cold of ≥ 5% of REE Exclusion Criteria: * Known hypersensitivity or allergy to caffeine * Concomitant medication other than prescription free analgesics (paracetamol and NSAID) and oral contraceptives * Other clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease, cardiac arrhythmia, hypertension, diabetes mellitus, hyper- or hypothyroidism) * History of depressive disorder or anxiety disorder * Smoker / habitual tobacco use * Habitual excessive alcohol use * Regular consumption of caffeine containing energy drinks * Weight change of \>5% within 3 months prior to inclusion * Systolic blood pressure \>140 mmHg and/or diastolic blood pressure \> 95 mmHg. * Resting heart rate \>90 bpm * Hypersensitivity to cold (e.g. Raynaud syndrome) * Known or suspected non-compliance, drug or alcohol abuse * Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant. * Enrolment of the investigator, his/her family members, employees, and other dependent persons * Enrolment into another study using ionizing radiation within the previous 12 months. * Pregnancy or lactation
Where this trial is running
Basel
- University Hospital Basel, Department of Endocrinology — Basel, Switzerland (Recruiting)
Study contacts
- Principal investigator: Matthias Betz, Prof. — University Hospital, Basel, Switzerland
- Study coordinator: Matthias Betz, Prof.
- Email: Matthias.Betz@usb.ch
- Phone: 0041 61 556 56 54
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.