Premium Nahrungsergänzungsmittel | artgerecht

Cortisol Axis Test – Types, Procedure and Results

The cortisol axis test is a diagnostic procedure used to evaluate the function of the hypothalamic-pituitary-adrenal axis and assess cortisol production in the body.

Regular tips about health Regular tips about health

Things worth knowing about "Cortisol Axis Test"

The cortisol axis test is a diagnostic procedure used to evaluate the function of the hypothalamic-pituitary-adrenal axis and assess cortisol production in the body.

What Is the Cortisol Axis Test?

The cortisol axis test is a medical diagnostic procedure used to assess the function of the hypothalamic-pituitary-adrenal (HPA) axis. This axis regulates the production and release of cortisol, a vital stress hormone that controls numerous body functions. The test helps determine whether the HPA axis is overactive or underactive and whether a disorder in cortisol production is present.

The HPA Axis and Cortisol

The HPA axis is a complex feedback system consisting of three key structures:

Hypothalamus: Releases corticotropin-releasing hormone (CRH).
Pituitary gland: Responds to CRH by secreting adrenocorticotropic hormone (ACTH).
Adrenal cortex: Produces cortisol in response to ACTH stimulation.

Cortisol influences metabolism, immune function, blood pressure, and the stress response. A disruption in this axis can have serious health consequences.

When Is the Cortisol Axis Test Performed?

The test is used when a dysfunction of the HPA axis is suspected. Common indications include:

Suspected Addison disease (primary adrenal insufficiency)
Suspected Cushing syndrome (cortisol excess)
Pituitary insufficiency or tumors
Unexplained fatigue, weight loss, or low blood pressure
Monitoring after long-term corticosteroid therapy
Suspected secondary or tertiary adrenal insufficiency

Test Procedures and Types

Several different test methods are available, selected based on the clinical question:

ACTH Stimulation Test (Synacthen Test)

In the ACTH stimulation test, synthetic ACTH (tetracosactide/Synacthen) is administered intravenously or intramuscularly. Blood samples are then taken at defined time points (usually 30 and 60 minutes) and cortisol levels are measured. A sufficient rise in cortisol indicates an intact adrenal cortex function.

Insulin Tolerance Test (ITT)

The insulin tolerance test is considered the gold standard for assessing the entire HPA axis. Insulin is administered to induce a controlled drop in blood sugar, which acts as a strong physiological stress stimulus, triggering the release of CRH, ACTH, and cortisol. Due to its risks (hypoglycemia), this test is only performed under close medical supervision.

CRH Stimulation Test

In the CRH test, synthetic CRH is injected and the ACTH and cortisol response of the pituitary gland is measured. This test helps distinguish between a pituitary disorder and a hypothalamic disorder.

Dexamethasone Suppression Test

The dexamethasone suppression test is used when Cushing syndrome is suspected. After taking the synthetic corticosteroid dexamethasone, suppression of the body's own cortisol production is assessed. A failure to suppress cortisol suggests pathological cortisol overproduction.

Interpreting the Results

Test results are always interpreted within the clinical context:

Insufficient cortisol response after stimulation: Suggests adrenal insufficiency (primary, secondary, or tertiary)
Lack of suppression after dexamethasone: Suggests Cushing syndrome
Normal cortisol response: Indicates an intact HPA axis

Laboratory values are always assessed together with symptoms and further diagnostic findings. A single measurement is generally not sufficient for a definitive diagnosis.

Risks and Side Effects

Most cortisol axis tests are well tolerated. The insulin tolerance test may cause symptoms of hypoglycemia (sweating, trembling, rapid heartbeat), which is why it is performed exclusively under strict medical supervision. The ACTH stimulation test and the dexamethasone suppression test are considered safe and can be performed on an outpatient basis.

References

Arlt W. et al. - Adrenal insufficiency. Lancet 2003; 361(9372): 1881-1893.
Nieman LK. et al. - The diagnosis of Cushing's syndrome: an Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology and Metabolism 2008; 93(5): 1526-1540.
Bornstein SR. et al. - Diagnosis and Treatment of Primary Adrenal Insufficiency: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology and Metabolism 2016; 101(2): 364-389.

Building Blocks for a Healthy Life

As an integrated manufacturer, we develop & produce evidence-based, patented, and non-patented formulations. We work exclusively with plant and natural extracts according to the strictest purity & quality standards.
The combination of science & modern technology with the laws of nature creates solutions consistently tailored to humans – for the highest good: health.

Most read entries

3 Posts in this encyclopedia category