New Biomarker May Improve Hypercortisolism Diagnosis

Researchers presented findings at ENDO 2026, the annual meeting of the Endocrine Society, indicating that measuring adrenocorticotropic hormone (ACTH) following a 1-mg overnight dexamethasone suppression test (DST) may lead to improved diagnosis of hypercortisolism. This approach aims to refine the identification of conditions characterized by excessive cortisol production, such as Cushing's disease.

The study focused on evaluating the diagnostic accuracy of this specific ACTH measurement protocol. Hypercortisolism can manifest in various ways, and its accurate diagnosis is crucial for timely and effective treatment. The traditional DST involves administering a dose of dexamethasone and then measuring cortisol levels to see if the body's natural cortisol production is suppressed. However, the effectiveness and interpretation of these tests can sometimes be challenging, leading to potential misdiagnoses or delays in diagnosis.

By incorporating the measurement of ACTH levels after the overnight DST, the researchers believe they can achieve a more precise assessment of the hypothalamic-pituitary-adrenal (HPA) axis function. ACTH is a hormone produced by the pituitary gland that stimulates the adrenal glands to produce cortisol. Abnormal ACTH levels can be indicative of the underlying cause of hypercortisolism, whether it originates from the pituitary gland itself (Cushing's disease) or from other sources.

The findings presented at ENDO 2026 suggest that this refined diagnostic strategy could offer a more sensitive and specific method for detecting hypercortisolism. This advancement holds the potential to benefit patients by enabling earlier and more accurate identification of the condition, paving the way for more targeted therapeutic interventions and improved patient outcomes. Further validation and clinical implementation of this biomarker measurement are anticipated.