The purpose of this study is to compare two different glucocorticoids, prednisolone and dexamethasone at two different doses for their organ specific effects, utilizing modern day standards.

Study design: A randomised, double blind, cross-over clinical trial.

Study population: healthy human adult volunteers including 12 males and 12 females aged 18-75 years old.

Intervention: In random order, subjects will receive 7,5 mg prednisolone for one week, directly followed by 30 mg of prednisolone for one week. After a washout period of 4 weeks (or by exception 8 weeks), subjects will receive 1,125 mg dexamethasone for one week, directly followed by 4,5 mg dexamethasone for one week.

Main study parameters/endpoints: The main study endpoint is the difference in total urinary cortisol excretion as measured in 24h-urine between the lower doses of prednisolone and dexamethasone as well as between the higher doses of prednisolone and dexamethasone.

Inclusion Criteria:

• Participants must be healthy with no relevant medical history and no use of medication.
• Female participants aged <50 years must be using oral contraceptives and female participants age ≥50 years must be in the postmenopausal state
• Command of the Dutch language
• Providing written IC
• BMI between 18.5 and 30 kg/m2
• Participants must be between 18 and 75 years of age

Exclusion Criteria:

• Potential participants who are unlikely to adhere to the study protocol (for instance subjects which have a history of substance abuse or non-compliance)

• Potential participants with a medical history of:

  1. Diseases affecting the HPA-axis: e.g. primary and secondary adrenal insufficiency, pituitary tumors, and nightshift workers
  2. Diseases affecting the HPG-axis: e.g. Cushing disease.
  3. Chronic inflammatory diseases: e.g. rheumatoid arthritis, polymyalgia rheumatic, and asthma
  4. Psychiatric diseases
  5. Diabetes

• Shift workers

• Potential participants with a kidney function <60 ml/min/1.73m2, abnormalities in liver enzymes, and/or abnormalities in thyroid function

• Potential participants who are dependent on corticosteroids, e.g. asthmatic patients, and transplant recipients

After deidentification, individual data that are the foundation of the results reported in future manuscripts can be made available (text, tables, figures, and appendices).

Beginning 6 months and ending 10 years following article publication

Researchers should provide a methodologically sound proposal to a.p.van.beek@umcg.nl