CONTEXT: The low-dose dexamethasone suppression test (LDDST) is widely used in confirming a diagnosis of Cushing's syndrome. CRH administration at the end of an LDDST has been reported to improve the diagnostic accuracy of this test. OBJECTIVE: Our objective was to assess whether CRH administration after a standard LDDST (LDDST-CRH test) improves diagnostic accuracy in Cushing's syndrome. DESIGN, SETTING, AND PARTICIPANTS: Thirty-six individuals with a clinical suspicion of Cushing's syndrome each completed a standard LDDST and an LDDST-CRH test at Hammersmith Hospitals NHS Trust, London. The LDDST involved administration of 0.5 mg oral dexamethasone given 6-hourly for 48 h. Serum cortisol was measured 6 h after the last dose of dexamethasone, with a value of 50 nmol/liter or below excluding Cushing's syndrome. Immediately after this, the LDDST-CRH test commenced with administration of a ninth dose of 0.5 mg dexamethasone. Exactly 2 h later, 100 mug human-sequence CRH was administered. Serum cortisol was measured 15 min after the CRH injection, with a value of less than 38 nmol/liter also excluding Cushing's syndrome. MAIN OUTCOME MEASURE: Diagnosis or exclusion of Cushing's syndrome was the main outcome measure. RESULTS: Twelve subjects were diagnosed with Cushing's syndrome (eight Cushing's disease and four primary adrenal). The sensitivity of the LDDST in diagnosing Cushing's syndrome was 100%, with a specificity of 88%. In contrast, although the sensitivity of the LDDST-CRH test was also 100%, specificity was reduced at 67%. These results give a positive predictive value of 80% for the LDDST and 60% for the LDDST-CRH test. CONCLUSION: This small study suggests that the addition of CRH to the LDDST does not improve the diagnostic accuracy of the standard LDDST in Cushing's syndrome.
CONTEXT: The low-dose dexamethasone suppression test (LDDST) is widely used in confirming a diagnosis of Cushing's syndrome. CRH administration at the end of an LDDST has been reported to improve the diagnostic accuracy of this test. OBJECTIVE: Our objective was to assess whether CRH administration after a standard LDDST (LDDST-CRH test) improves diagnostic accuracy in Cushing's syndrome. DESIGN, SETTING, AND PARTICIPANTS: Thirty-six individuals with a clinical suspicion of Cushing's syndrome each completed a standard LDDST and an LDDST-CRH test at Hammersmith Hospitals NHS Trust, London. The LDDST involved administration of 0.5 mg oral dexamethasone given 6-hourly for 48 h. Serum cortisol was measured 6 h after the last dose of dexamethasone, with a value of 50 nmol/liter or below excluding Cushing's syndrome. Immediately after this, the LDDST-CRH test commenced with administration of a ninth dose of 0.5 mg dexamethasone. Exactly 2 h later, 100 mug human-sequence CRH was administered. Serum cortisol was measured 15 min after the CRH injection, with a value of less than 38 nmol/liter also excluding Cushing's syndrome. MAIN OUTCOME MEASURE: Diagnosis or exclusion of Cushing's syndrome was the main outcome measure. RESULTS: Twelve subjects were diagnosed with Cushing's syndrome (eight Cushing's disease and four primary adrenal). The sensitivity of the LDDST in diagnosing Cushing's syndrome was 100%, with a specificity of 88%. In contrast, although the sensitivity of the LDDST-CRH test was also 100%, specificity was reduced at 67%. These results give a positive predictive value of 80% for the LDDST and 60% for the LDDST-CRH test. CONCLUSION: This small study suggests that the addition of CRH to the LDDST does not improve the diagnostic accuracy of the standard LDDST in Cushing's syndrome.
Authors: Lynnette K Nieman; Beverly M K Biller; James W Findling; John Newell-Price; Martin O Savage; Paul M Stewart; Victor M Montori Journal: J Clin Endocrinol Metab Date: 2008-03-11 Impact factor: 5.958
Authors: Maria Fleseriu; Richard Auchus; Irina Bancos; Anat Ben-Shlomo; Jerome Bertherat; Nienke R Biermasz; Cesar L Boguszewski; Marcello D Bronstein; Michael Buchfelder; John D Carmichael; Felipe F Casanueva; Frederic Castinetti; Philippe Chanson; James Findling; Mônica Gadelha; Eliza B Geer; Andrea Giustina; Ashley Grossman; Mark Gurnell; Ken Ho; Adriana G Ioachimescu; Ursula B Kaiser; Niki Karavitaki; Laurence Katznelson; Daniel F Kelly; André Lacroix; Ann McCormack; Shlomo Melmed; Mark Molitch; Pietro Mortini; John Newell-Price; Lynnette Nieman; Alberto M Pereira; Stephan Petersenn; Rosario Pivonello; Hershel Raff; Martin Reincke; Roberto Salvatori; Carla Scaroni; Ilan Shimon; Constantine A Stratakis; Brooke Swearingen; Antoine Tabarin; Yutaka Takahashi; Marily Theodoropoulou; Stylianos Tsagarakis; Elena Valassi; Elena V Varlamov; Greisa Vila; John Wass; Susan M Webb; Maria C Zatelli; Beverly M K Biller Journal: Lancet Diabetes Endocrinol Date: 2021-10-20 Impact factor: 32.069
Authors: Elena Valassi; Brooke Swearingen; Hang Lee; Lisa B Nachtigall; Daniel A Donoho; Anne Klibanski; Beverly M K Biller Journal: J Clin Endocrinol Metab Date: 2009-10-22 Impact factor: 5.958
Authors: Dalia L Batista; Nikos Courcoutsakis; Jehan Riar; Margaret F Keil; Constantine A Stratakis Journal: J Clin Endocrinol Metab Date: 2008-08-26 Impact factor: 5.958