title: An overnight high-dose dexamethasone suppression test for rapid differential diagnosis of Cushing's syndrome.
abstract: We have developed a high-dose dexamethasone suppression test that can be administered overnight with a single 8-mg dose and used the new procedure in the differential diagnosis of 83 patients with Cushing's syndrome. In 76 patients with surgically or pathologically proven cause--60 with Cushing's disease, 7 with the ectopic adrenocorticotrophic hormone syndrome, and 9 with adrenal tumors--suppression of plasma cortisol levels to less than 50% of baseline indicated a diagnosis of Cushing's disease. The test had a sensitivity of 92%, a specificity of 100%, and a diagnostic accuracy of 93%. These values equal or exceed those of the standard 2-day test whether based on suppression of urinary 17-hydroxycorticosteroids or plasma cortisol. We conclude that this overnight, high-dose dexamethasone suppression test is practical and reliable in the differential diagnosis of Cushing's syndrome.
mesh_terms: D015065:17-Hydroxycorticosteroids / Q000652:urine; D000182:ACTH Syndrome, Ectopic / Q000175:diagnosis; D000236:Adenoma / Q000175:diagnosis; D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis; D002648:Child; D003480:Cushing Syndrome / Q000175:diagnosis* / Q000378:metabolism; D003864:Depression, Chemical; D003907:Dexamethasone / Q000008:administration & dosage; D003937:Diagnosis, Differential; D004334:Drug Administration Schedule; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged
chemical_list: D015065:17-Hydroxycorticosteroids; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone