Rationale: Case reports describe suppression of the hypothalamic-pituitary-adrenal (HPA) axis caused by local corticosteroids, most often with inhalation corticosteroids. The exact prevalence is not known. Early recognition is important, because suppression of the HPA-axis can lead to significant morbidity and mortality. Suppression of the HPA axis might occur more often when a Cytochrome P450 3A4 (CYP3A4) inhibitor, e.g. ritonavir, is used next to the local corticosteroid, a combination often used by human immunodeficiency virus (HIV)-patients. Cortisol can be determined in hair. This non-invasive analysis could help in diagnosis of suppressed HPA-axis.

Research questions:

Primary objective:

1. How often do inhalation or nasal corticosteroids lead to suppression of the HPA- axis in HIV-treated patients?

   Secondary objectives:

2. Are other variables associated with the HPA-axis suppression?

3. Are cortisol measurements in hair as reliable as serum cortisol or an Adrenocorticotropic hormone (ACTH) stimulation test to diagnose suppression of the HPA axis? Study design: cross-sectional explorative study Study population: adults treated for HIV and using an inhalation or nasal corticosteroid.

Intervention: an ACTH stimulation test, cortisol measurements in blood and hair.

Main study parameters/endpoints:

Proportions of persons with a low morning plasma cortisol or low cortisol after an ACTH stimulation test. Correlation between cortisol in plasma and hair cortisol.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Each person will be screened with a history and a short physical examination. A venous cannula will be inserted for obtaining blood for the plasma cortisol and for the ACTH stimulation test. An ACTH stimulation test has no major complications. A piece of hair is cut for cortisol hair analysis. The risks and burden are minimal, while the future benefits could be great since suppression of the endogenous HPA- axis can be associated with morbidities like hypertension or osteoporosis and can even lead to an adrenal crisis when the local corticosteroid is stopped.

Inclusion Criteria:

• Receive a treatment for HIV-infection
• > 18 years old
• Current usage of inhalation or nasal corticosteroids, for at least two weeks
• Willing to give informed consent

Exclusion Criteria:

• adrenal insufficiency
• Concurrent use of topical corticosteroids, usage of oral corticosteroids in the last three months. Intramuscular or intra-articular corticosteroid injections in the last year.
• Contra-indications for tetracosactide: allergy for tetracosactide, Cushings's syndrome, refractory heart failure, peptic ulcer, acute psychosis, adrenogenital syndrome
• If the patient ever had an ACTH-stimulation test before
• Pregnant female or breast-feeding female.
• Use of oral contraceptives, since these can heighten the cortisol-binding globulin
• Exclusion criterion for the cortisol measurements in hair: baldness