Midnight salivary cortisol determination for assessing the outcome of transsphenoidal surgery in Cushing's disease.
BACKGROUND
Midnight salivary cortisol (MSC) is now recognized as a reliable index for Cushing's syndrome diagnosis but has to be validated for the follow-up of treated patients.


OBJECTIVE
Our objective was to evaluate MSC for assessing the outcome of transsphenoidal surgery (TSS) in patients with Cushing's disease (CD).


METHODS
We conducted a retrospective cohort study in a single center.


METHODS
Sixty-eight patients treated by TSS between 1996 and 2006 and followed for at least 6 months with postoperative MSC were included. Mean follow-up (+/- sd) was 45 +/- 31 months. Morning plasma cortisol was determined 5 d after TSS, and MSC and urinary cortisol (UC) were determined 6-12 months after surgery. The remission group included hypocortisolic (morning plasma cortisol < 50 ng/ml and/or insufficient response to cosyntropin) and eucortisolic (midnight plasma cortisol < 75 ng/ml and normal UC) patients. Patients in the treatment failure group had high midnight plasma cortisol and UC concentrations.


RESULTS
Fifty patients (74%) were in remission. Mean MSC was 0.7 +/- 0.4 ng/ml (range, 0.4-2.1 ng/ml) and 6.5 +/- 6.5 ng/ml (range, 2.1-27.2 ng/ml) for the remission and treatment failure groups, respectively (P = 0.001). A cutoff of 2 ng/ml for MSC gave a sensitivity of 100% and a specificity of 98% for treatment failure diagnosis, whereas UC less than 90 microg/d had a sensitivity of 71% and specificity of 98%. Postsurgical morning plasma cortisol less than or equal to 18 ng/ml had a sensitivity of 93% and specificity of 74%.


CONCLUSIONS
MSC is a simple, robust marker of remission after TSS for CD.
Carrasco
Carmen A
CA
Service des Maladies Endocriniennes et Métaboliques, Hôpital Cochin, 27 rue du Faubourg Saint-Jacques, 75014 Paris, France.
Coste
Joël
J
Guignat
Laurence
L
Groussin
Lionel
L
Dugué
Marie Annick
MA
Gaillard
Stéphane
S
Bertagna
Xavier
X
Bertherat
Jérôme
J
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis* / Q000378:metabolism* / Q000652:urine; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D047748:Pituitary ACTH Hypersecretion / Q000378:metabolism* / Q000601:surgery*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism*; D016896:Treatment Outcome
D006854:Hydrocortisone