General information
  • Disease category Basic research (Anatomy/Physiology) (BASEC)
  • Study Phase N/A (ICTRP)
  • Recruitment status recruitment ongoing (BASEC/ICTRP)
  • Trial sites
    Basel
    (BASEC)
  • Contact Prof. Dr. Matthias Betz matthias.betz@usb.ch (BASEC)
  • Data Source(s) BASEC: Import from 12.03.2026 ICTRP: Import from 07.02.2026
  • Last update 12.03.2026 09:26
HumRes66973 | SNCTP000006436 | BASEC2025-00637 | NCT06978777

Effect of Caffeine on Cold-Stimulated Activity of Brown Adipose Tissue.

  • Disease category Basic research (Anatomy/Physiology) (BASEC)
  • Study Phase N/A (ICTRP)
  • Recruitment status recruitment ongoing (BASEC/ICTRP)
  • Trial sites
    Basel
    (BASEC)
  • Contact Prof. Dr. Matthias Betz matthias.betz@usb.ch (BASEC)
  • Data Source(s) BASEC: Import from 12.03.2026 ICTRP: Import from 07.02.2026
  • Last update 12.03.2026 09:26

Summary description of the study

Brown adipose tissue is important for energy balance in many animals, human infants, and even many adults, as it can 'burn' energy and convert it into heat. It is referred to as 'healthy' fat tissue and has many benefits for various metabolic diseases such as diabetes mellitus, obesity, and cholesterol metabolism disorders. Since the amount and activity of brown adipose tissue decrease with age and body weight, it has mainly been studied in animals, and we know little about how energy expenditure can be activated in adults. The natural stimulus for increased energy expenditure in brown fat is cold, presumably through the activation of so-called β-adrenergic receptors. Animal studies have shown that not only β-adrenergic receptors are important for the activation of brown adipose tissue, but also a co-activation by so-called adenosine receptors (A2A receptors) is necessary. Caffeine is an antagonist of these A2A receptors and should therefore inhibit this receptor effect. In this study, we want to take a closer look at the effect of caffeine on brown adipose tissue by administering 200 mg of caffeine and a placebo (as a control) to the study participants, followed by measuring energy expenditure using calorimetry and assessing the activity of brown adipose tissue with an FDG-PET/CT. This research project is a basic scientific clinical study aimed at clarifying how energy metabolism is activated in the human body. The study will be conducted at the University Hospital Basel.

(BASEC)

Intervention under investigation

We compare the effect of 200 mg of caffeine and placebo on the activity of brown adipose tissue after mild cold stimulation.

(BASEC)

Disease under investigation

Healthy Volunteers

(BASEC)

Criteria for participation in trial
- healthy volunteer subjects - moderate caffeine consumption (1 to 3 cups per day) - BMI 18.5-25 kg/m2 (BASEC)

Exclusion criteria
- intolerance to caffeine - thyroid disease - smokers (BASEC)

Trial sites

Basel

(BASEC)

Switzerland (ICTRP)

Sponsor

Universitätsspital Basel

(BASEC)

Contact

Contact Person Switzerland

Prof. Dr. Matthias Betz

0041 61 265 5078

matthias.betz@usb.ch

Universitätsspital Basel Klinik Endokrinologie, Diabetologie und Metabolism Petersgraben 4 4031 Basel

(BASEC)

General Information

University Hospital, Basel, Switzerland

0041 61 556 56 540041 61 556 56 54

matthias.betz@usb.chmatthias.betz@usb.ch

(ICTRP)

Name of the authorising ethics committee (for multicentre studies, only the lead committee)

Ethics Committee northwest/central Switzerland EKNZ

(BASEC)

Date of authorisation

11.06.2025

(BASEC)


ICTRP Trial ID
NCT06978777 (ICTRP)

Official title (approved by ethics committee)
Effect of caffeine on cold-stimulated brown adipose tissue activity (ACROBAT Trial) (BASEC)

Academic title
Effect of Caffeine on Cold-stimulated Brown Adipose Tissue Activity (ICTRP)

Public title
Effect of Caffeine on Cold-stimulated Brown Adipose Tissue Activity (ICTRP)

Disease under investigation
Brown Adipose Tissue (BAT) PhysiologyCold Exposure (ICTRP)

Intervention under investigation
Drug: Caffeine (200 mg)Drug: Placebo (ICTRP)

Type of trial
Interventional (ICTRP)

Trial design
Allocation: Randomized. Intervention model: Crossover Assignment. Primary purpose: Basic Science. Masking: Triple (Participant, Investigator, Outcomes Assessor). (ICTRP)

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 REEExclusion 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 (ICTRP)

not available

Primary and secondary end points
BAT SUVmean (ICTRP)

BAT SUVmax;BAT Volume;Cold induced thermogenesis (CIT);Resting energy expenditure (REE);Respiratory exchange ratio (RER):;Skin temperature;Metabolom and Lipidome profile;Caffeine and its metabolites (ICTRP)

Registration date
not available

Incorporation of the first participant
not available

Secondary sponsors
not available

Additional contacts
Matthias Betz, Prof.Matthias Betz, Prof.Matthias Betz, Prof., Matthias.Betz@usb.chmatthias.betz@usb.ch, 0041 61 556 56 540041 61 556 56 54, University Hospital, Basel, Switzerland (ICTRP)

Secondary trial IDs
ACROBAT_V1_1 (ICTRP)

Results-Individual Participant Data (IPD)
not available

Further information on the trial
https://clinicaltrials.gov/study/NCT06978777 (ICTRP)

Results of the trial

Results summary

not available

Link to the results in the primary register

not available