Pros and cons of dexamethasone suppression test for screening of subclinical Cushing’s syndrome in patients with adrenal incidentalomas

• Published in: Journal of endocrinological investigation 2011, Vol.34 (1), p.e1-e5
• Main Authors: Reimondo, G., Allasino, B., Bovio, S., Saba, L., Ardito, A., Angeli, A., Terzolo, M.
• Format: Article
• Language: English
• Subjects: Adrenal Gland Neoplasms - complications; Adrenal Gland Neoplasms - diagnosis; Adult; Aged; Aged, 80 and over; Asymptomatic Diseases; Contraindications; Cushing Syndrome - diagnosis; Cushing Syndrome - etiology; Dexamethasone - pharmacology; Dexamethasone - therapeutic use; Endocrinology; Female; Humans; Hypothalamo-Hypophyseal System - metabolism; Hypothalamo-Hypophyseal System - physiopathology; Male; Mass Screening - methods; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; Original Articles; Pituitary-Adrenal Function Tests - methods; Pituitary-Adrenal Function Tests - standards; Pituitary-Adrenal System - metabolism; Pituitary-Adrenal System - physiopathology; Retrospective Studies
• ISSN: 0391-4097; 1720-8386
• DOI: 10.1007/BF03346701

The results of dexamethasone suppression tests (DST) in the screening of subclinical hypercortisolism are not readily comparable. Aim of the present study was to review the effectiveness of overnight 1-mg DST and 8-mg DST to look for functional autonomy of clinically inapparent adrenal adenomas. Sixty-eight consecutive patients with clinically inapparent adrenal adenomas were enrolled. All patients underwent 1-mg DST. The 8-mg DST was performed in the 11 patients who had post 1-mg DST cortisol >138 nmol/l and in 11 patients who had post 1-mg DST cortisol between 50 and 138 nmol/l. The a priori probability to have autonomous cortisol secretion was defined by the presence of at least two alterations of the hypothalamic-pituitary-adrenal axis among reduced ACTH concentrations, elevated urinary free cortisol (UFC) or elevated midnight serum cortisol. Cortisol levels >138 nmol/l after the 1-mg DST increases the post-test probability of adrenal functional autonomy to 55%, whereas cortisol levels 138 nmol/l after the 1-mg DST maintained cortisol above this cut-point. The 1-mg DST should be considered as the more effective test to detect autonomous cortisol secretion by a clinically inapparent adrenal adenoma when cortisol levels are >138 nmol/l, while cortisol levels