The purpose of this study is to elucidate the effects of Fluvastatin on brown adipose tissue activity in humans.

Statins, inhibitors of cholesterol biosynthesis, act by inhibiting the enzyme of the mevalonate pathway. Although the clinical benefits of statins are undisputable, they have been shown to increase insulin resistance and incidence of type 2 diabetes mellitus, the mechanism of which is currently not clear.

The main function of brown adipose tissue (BAT) is non-shivering thermogenesis (i.e. heat production through energy dissipation) in brown adipocytes. There has been a growing interest in BAT as a novel therapeutic approach to increase energy expenditure in order to facilitate weight-loss and increase insulin sensitivity.

BAT activity will be assessed using calorimetric test and [18F]-Fluorodeoxyglucose (FDG) positron emission tomography (PET).

We speculate that statins inhibit BAT function and that this mechanism may contribute to the above mentioned increase in insulin resistance.

Inclusion Criteria:

• Male volunteers (18-40 y)
• body mass index 19 to 27 kg/m²
• Fluent in German or English

Exclusion Criteria:

• Regular physical exercise of more than >150 min of exercise per week.
• Contraindications to the class of drugs under study, e.g. known hypersensitivity or allergy to class of drugs or the investigational product,
• Other clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease, etc.),
• Clinically indicated intake of the following medications: Corticosteroids, CYP3A4-Inhibitors (Itraconazol, Voriconazol, Fluconazol, Clarithromycin, Erythromycin, Indinavir, Nelfinavir, Ritonavir, Grapefruit juice), Beta-Blocker, Neuroleptics, Tricyclic Antidepressants,
• 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,
• Participation in another study with investigational drug within the 30 days preceding and during the present study,
• Participation in another study involving ionizing radiation in the same year,
• Previous enrolment into the current study,
• Enrolment of the investigator, his/her family members, employees and other dependent persons,
• MRI contraindications: Not MRI-compatible metal in the body, cardiac pacemaker, History of surgery with possible metal clips/parts still in the body, claustrophobia.
• Resting pulse rate > 70 bpm
• Known arterial hypertension or resting blood pressure > 130/80 mmHg.
• frequence corrected QT-time (QTc) >430 ms
• Serum creatinine > 1.5x upper limit of norm (ULN), i.e.> 145 µmol/L
• creatine kinase > 1.5x ULN, i.e. > 300 U/L
• aspartate transaminase (ASAT) > 1.5x ULN, i.e. > 51 U/L
• alanine aminotransferase (ALAT) > 1.5x ULN, i.e. > 88 U/L
• Hypothyroidism
• Vitamin D deficiency, Vitamin D3 < 25 nmol/L
• Intake of anticoagulants or inhibitors of platelet aggregation (e.g. Aspirin, clopidogrel).
• Known tendency to form keloids (hypertrophic scar tissue)