[Evaluation of the 1 mg overnight dexamethasone suppression test in the diagnosis of the subclinical Cushing's syndrome in patients with Adrenal Incidentaloma].
OBJECTIVE
To evaluate efficacy of the 1 mg overnight dexamethasone suppression test (1 mg overnight DST) in the diagnosis of subclinical Cushing's syndrome, and to explore the best diagnostic cut-off value.


METHODS
The clinical data of patients with adrenal incidentaloma in Chinese PLA General Hospital from 1995 to 2013 were gathered. The data of subclinical Cushing's syndrome (SCS) and non-functional adrenal adenoma (NFA) was retrospectively analyzed. The ROC curve was used to evaluate the efficacy of the 1 mg overnight DST and to explore the best cut-off value with high sensitivity and specificity.


RESULTS
There were 447 patients with NFA (224 male and 223 female), and the mean age was 53±11 years old.49 patients were with SCS (19 male and 30 female), and the mean age was 47±12 years old. The area under the ROC of serum cortisol level after 1 mg overnight DST was 0.967 (95%CI: 0.942-0.993). The best cut-off value of serum cortisol after 1 mg overnight DST was 63.65 nmol/L, with a sensitivity of 100.0% and a specificity of 88.8%. The best cut-off value of the suppression ratio of serum cortisol was 85.64%, with a sensitivity of 83.3% and a specificity of 84.6%.


CONCLUSIONS
The best criterion for 1 mg overnight DST in the diagnosis of SCS was serum cortisol level , and the recommend cut-off point was 63.65 nmol/L, with both a higher sensitivity and specificity. The suppression ratio of serum cortisol after 1 mg overnight DST was also considered as a suitable criterion in the diagnosis of SCS.
Department of Endocrinology, Chinese PLA General Hospital, Beijing 100853, China; #Department of Endocrinology, the 264th Hospital of PLA, Taiyuan 030001, China.
Lele
L
Li
Baiyu
B
Han
Jingtao
J
Dou
Guoqing
G
Yang
Weijun
W
Gu
Zhaohui
Z
Lü
Yiming
Y
Mu
D000310:Adrenal Gland Neoplasms; D003480:Cushing Syndrome; D003907:Dexamethasone; D005260:Female; D006801:Humans; D006854:Hydrocortisone; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies
D003907:Dexamethasone; D006854:Hydrocortisone