ECE2017 Eposter Presentations: Adrenal and Neuroendocrine Tumours Adrenal cortex (to include Cushing's) (86 abstracts)
Late-night salivary cortisol: cut-off definition and diagnostic value in Cushing’s syndrome
Adriana Lages 1 , João Frade 1 , Isabel Paiva 1 , Patrícia Oliveira 1 , Diana Oliveira 1 , Diana Martins 1 , Mara Ventura 1 , Nelson Cunha 1 , Alexandre Rebelo-Marques 2 , Susana Antunes 1 , Fátima Leitão 1 & Francisco Carrilho 1
1Coimbra Hospital and University Center, Coimbra, Portugal; 2Faculty of Medicine University of Coimbra, Coimbra, Portugal.
Background: The diagnosis of Cushing’s syndrome (CS) remains a challenge in clinical endocrinology. Several screening tests have been proposed to establish hypercortisolism. Late-night salivary cortisol (LNSC) is used as screening tool, however, individualized cut-off levels for each population must be defined.
Methods: Three group of subjects were studied: healthy volunteers, suspected CS and proven CS. All patients collected saliva at 23.00 h using a Salivette. Salivary Cortisol was measured using an automated electrochemiluminescence assay – Elecsys 2010-Roche. The functional sensitivity of the assays is 0.018 μg/dl. Diagnostic cut-off level was defined by Receiver operating characteristic (ROC) curve and Youden’s J index.
Results: We studied 127 subjects: 57 healthy volunteers, 39 patients with suspected CS and 31 with proven CS (ACTH-dependent: 22 pituitary, two ectopic; ACTH-independent: two adrenal adenoma, five adrenal carcinoma).
The 2.5th–97.5th percentile of the LNSC concentrations in normal subjects was 0.054–0.1827 μg/dl, respectively. The mean±S.D. LNSC concentration in patients with proven CS (0.6798±0.52 μg/dl) was significantly higher than those in normal subjects (0.0642±0.03 μg/dl; P<0.0001) and suspected CS group (0.1803±0.19 μg/dl; P<0.0001).
ROC curve analysis showed an AUC of 0.9881 (P<0.0001) and a cut-off point of 0.1 μg/dl provides a sensibility (S) of 96.77% (95%CI 83.3-99.92%) and specificity (E) of 91.23% (95%CI 80.7–97.09%).
There were significant correlations between LNSC and late-night serum cortisol (LNSeC) levels (r=0.6977; P<0.0001) as well as with Urinary Free Cortisol (UFC) levels (r=0.5404; P 0.0025) in proven CS group.
Conclusion: Our results give to LNSC an excellent accuracy and reaffirm that can be used as a highly reliable noninvasive screening tool for outpatient assessment. In our population, the LNSC reference cut-off was 0.1 μg/dl with S 96.77% and E 91.23% for CS diagnosis. Given its convenience and diagnostic accuracy, LNSC may profitably be added to traditional screening tests such as LNSeC and UFC.
Article tools
My recent searches
My recently viewed abstracts
Authors
Endocrine Abstracts
ISSN 1470-3947 (print) | ISSN 1479-6848 (online)
© Bioscientifica 2024 |
Privacy policy |
Cookie settings
BiosciAbstracts
Bioscientifica Abstracts is the gateway to a series of products that provide a permanent, citable record of abstracts for biomedical and life science conferences.
Find out more