title: [Diagnostic value of salivary cortisol in Cushing's syndrome].
abstract: OBJECTIVE
  To evaluate the usefulness of the measurement of midnight salivary cortisol (SC) in the initial diagnosis of Cushing's syndrome (CS).
  
  
  METHODS
  A total of 18 patients with pathologically confirmed CS were recruited in the study. Thirteen patients with pure obesity and 36 healthy people served as controls. Salivary samples at 8:00, 16:00, 24:00 and 8:00 the next day after the 1 mg dexamethasone suppression test(DST) were collected by a commercially-available saliva collection device, and assayed by Electro Chemiluminescence Immuno Assay (ECLIA).
  
  
  RESULTS
  There were highly significant correlations between salivary cortisol and plasma cortisol (PTC) at the 4 time points. The correlation coefficient was 0.73 (0.71, 0.74, 0.78 and 0.61 at the four time points, respectively) (P < 0.05). Midnight salivary cortisol level in Cushing's Syndrome [(10.58 +/- 5.17) nmol/L] was significantly higher than healthy people [(1.55 +/- 0.60) nmol/L]. The receiver operating characteristics curve (ROC) analysis showed a sensitivity of 100.00% and specificity of 84.00% at 8:00 with the cut-off point of 6.21 nmol/L.
  
  
  CONCLUSIONS
  The measurement of midnight salivary cortisol is a convenience and noninvasive screening test for the initial diagnosis of Cushing's Syndrome.
authors.affiliation: Division of Hormone Assay, Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Shao-rui
authors.initials: SR
authors.lastname: Shi
authors.forename: Wei
authors.initials: W
authors.lastname: Gan
authors.forename: Xi-ting
authors.initials: XT
authors.lastname: Zhou
authors.forename: Zhong-yun
authors.initials: ZY
authors.lastname: Xiong
authors.forename: Zhen-mei
authors.initials: ZM
authors.lastname: An
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D003480:Cushing Syndrome / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis* / Q000097:blood; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry*; D013997:Time Factors; D055815:Young Adult
chemical_list: D006854:Hydrocortisone