Glucocorticoid Long-term Administration: Effect on Cold Induced Energy Expenditure and Resting Metabolic Rate

Glucocorticoid Long-term Administration: Effect on Cold Induced Energy Expenditure and Resting Metabolic Rate

The aim of the study is to investigate whether treatment with glucocorticoids leads to a change in heat production of the human body at mild cold conditions.

Brown adipose tissue (BAT) is a thermogenic tissue that can convert chemical energy directly into heat due to the expression of uncoupling protein 1 (UCP1) protein. Data from preclinical studies shows that glucocorticoids (GCs) inhibit the function of BAT. In clinical practice GCs are often administered due tue their antiinflammatory properties making the investigation of short term (e.g. one week) and long therm (several months) effects practically relevant. This study's objective is to evaluate the effect of glucocorticoid treatment on cold induced thermogenesis (CIT) in humans.

Inclusion Criteria:

• Planned therapy with at least 7.5 mg prednisone equivalent per day or higher for more than 28 days (group A)
• Planned weaning off glucocorticoid therapy which lasted al least 28 days with a dosage of at least 7.5 mg prednisone (group B)
• BMI 19-30 kg/m2
• Informed Consent as documented by signature

Exclusion Criteria:

• Insufficient thyroid hormone substitution in case of hypothyroidism
• Uncontrolled diabetes mellitus (HbA1c >7.5%)
• Severe concomitant diseases: chronic heart failure, liver cirrhosis, kidney failure, active cancer
• Known hypersensitivity to cold, e.g. primary or secondary Raynaud's Syndrome
• Known or suspected non-compliance
• Abuse of alcohol or illicit drugs
• Claustrophobia
• Women who are pregnant or breast feeding
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc of the participant
• Previous enrolment into the current study
• Enrolment into another study using ionizing radiation within the previous 12 months