title: Use of the desmopressin test in the differential diagnosis of pseudo-Cushing state from Cushing's disease.
abstract: BACKGROUND
  The desmopressin (DDAVP) test has been proposed to discriminate Cushing's disease (CD) from pseudo-Cushing states (PC); however, current information on its value is scarce and contradictory.
  
  
  OBJECTIVE
  The aim of the study was to assess the ability of the DDAVP test in distinguishing between these conditions, with emphasis on subjects with mild hypercortisolism.
  
  
  METHODS
  We conducted a retrospective/prospective study at the Division of Endocrinology, Polytechnic University of Marche, Ancona, Italy.
  
  
  METHODS
  The study included 52 subjects with CD, 28 with PC, and 31 control subjects (CT).
  
  
  METHODS
  We performed the DDAVP test and standard diagnostic procedures for the diagnosis of Cushing's syndrome.
  
  
  METHODS
  The diagnosis/exclusion of CD was measured.
  
  
  RESULTS
  Interpretation of the DDAVP test based on percentage and absolute increment of cortisol and ACTH did not afford acceptable values of both sensitivity (SE) and specificity (SP). CD diagnosis based on simultaneous positivity for basal serum cortisol greater than 331 nmol/liter and absolute ACTH increment greater than 4 pmol/liter and its exclusion in subjects negative for one or both measures yielded an SE of 90.3% and an SP of 91.5%. The approach was also highly effective in distinguishing PC from: 1) CD with moderate values of urinary free cortisol (SE, 86.9%; SP, 92.8%); 2) CD with moderate values of serum cortisol after dexamethasone suppression (SE, 86.6%; SP, 92.8%); and 3) CD with moderate values of midnight serum cortisol (SE, 100%; SP, 92.8%).
  
  
  CONCLUSIONS
  Interpretation of the DDAVP test through a combination of parameters allowed effective discrimination of CD from PC, even in subjects with mild hypercortisolism.
authors.affiliation: Clinica di Endocrinologia, Ospedali Riuniti, Via Conca 71, 60020 Ancona, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Tirabassi
authors.forename: Emanuela
authors.initials: E
authors.lastname: Faloia
authors.forename: Roberta
authors.initials: R
authors.lastname: Papa
authors.forename: Giorgio
authors.initials: G
authors.lastname: Furlani
authors.forename: Marco
authors.initials: M
authors.lastname: Boscaro
authors.forename: Giorgio
authors.initials: G
authors.lastname: Arnaldi
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D003480:Cushing Syndrome / Q000097:blood / Q000175:diagnosis*; D003894:Deamino Arginine Vasopressin; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000652:urine; D008297:Male; D047748:Pituitary ACTH Hypersecretion / Q000097:blood / Q000175:diagnosis* / Q000652:urine; D011446:Prospective Studies; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
chemical_list: D003894:Deamino Arginine Vasopressin; D006854:Hydrocortisone