title: Is the 250 μg ACTH test a useful tool for the diagnosis of central hypoadrenalism in adult patients with pituitary disorders?
abstract: OBJECTIVE
  The diagnosis of hypothalamic-pituitary-adrenal insufficiency (HPAI) is a major clinical challenge. The gold standard procedure remains insulin tolerance test (ITT). This study aimed to evaluate the usefulness of standard-dose corticotrophin stimulation test (SDCT) in diagnosing HPAI.
  
  
  METHODS
  In this prospective study we performed SDCT and ITT in 55 consecutive patients (37F/18M) affected by pituitary disorders.
  
  
  RESULTS
  A normal response to ITT was found in 44 patients, while HPAI was diagnosed in 11. Using ITT as reference test, the ROC curve showed that a cortisol value of 18 µg/dl (500 nmol/L) at 30 min or 21.8 µg/dl (600 nmol/L) at 60 min after SDCT represents the best compromise between sensitivity and specificity in diagnosing HPAI. Moreover, 30 min cortisol values >20.3 µg/dl (560 nmol/L) or 60 min cortisol values >24.1 µg/dl (665 nmol/L) exclude HPAI. Four out of 15 patients of Group A, previously non-respondent to SDCT, showed a normal response to a second SDCT.
  
  
  CONCLUSIONS
  SDCT is not a reliable tool to identify HPAI, but it appears to be more useful in confirming the normality of HPA function. When SDCT fails to exclude HPAI, ITT should be performed. If ITT is contraindicated, retesting patients by SDCT is useful before starting an unnecessary replacement therapy.
authors: Department of Medical Sciences, University of Milan, Endocrinology and Diabetology Unit, Fondazione IRCCS Cà Granda Policlinico, Milan, Italy. leleferrante@gmail.com
authors: Emanuele
authors: E
authors: Ferrante
authors: Valentina
authors: V
authors: Morelli
authors: Claudia
authors: C
authors: Giavoli
authors: Giovanna
authors: G
authors: Mantovani
authors: Elisa
authors: E
authors: Verrua
authors: Elisa
authors: E
authors: Sala
authors: Elena
authors: E
authors: Malcmiodi
authors: Silvia
authors: S
authors: Bergamaschi
authors: Eriselda
authors: E
authors: Profka
authors: Elisa
authors: E
authors: Cairoli
authors: Serena
authors: S
authors: Palmieri
authors: Iacopo
authors: I
authors: Chiodini
authors: Andrea Gerardo
authors: AG
authors: Lania
authors: Anna
authors: A
authors: Spada
authors: Paolo Beck
authors: PB
authors: Peccoz
mesh_terms: D000309:Adrenal Insufficiency / Q000175:diagnosis*; D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage; D000328:Adult; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D007328:Insulin; D008297:Male; D008875:Middle Aged; D010900:Pituitary Diseases / Q000175:diagnosis*; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D007328:Insulin; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone