1. The diagnostic accuracy of increased late night salivary cortisol for Cushing’s syndrome: a real-life prospective study
- Author
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Giorgio Arnaldi, Grazia Michetti, Laura Trementino, Giorgia Marcelli, Marina Brugia, Filippo Ceccato, Maria Cristina De Martino, and Carolina Concettoni
- Subjects
Adult ,Male ,medicine.medical_specialty ,Hydrocortisone ,Endocrinology, Diabetes and Metabolism ,030209 endocrinology & metabolism ,Diagnostic accuracy ,Gastroenterology ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Internal medicine ,Diagnosis ,medicine ,Humans ,In patient ,Prospective Studies ,Saliva ,Prospective cohort study ,Late night salivary cortisol ,Cushing Syndrome ,Cortisol level ,Salivary cortisol ,Aged ,Chemiluminescence assay ,S syndrome ,business.industry ,Liquid chromatography–tandem mass spectrometry ,Retrospective cohort study ,Middle Aged ,Prognosis ,Circadian Rhythm ,Clinical Practice ,Diabetes and Metabolism ,Cushing’s syndrome ,Case-Control Studies ,030220 oncology & carcinogenesis ,Dexamethasone suppression test ,Female ,business ,Biomarkers ,Follow-Up Studies - Abstract
A prompt diagnosis of Cushing’s Syndrome (CS) in high-risk populations is mandatory: 1-mg dexamethasone suppression test (1-mg DST), late night salivary cortisol (LNSC), and urinary-free cortisol (UFC) are recommended, despite thresholds calculated in retrospective studies. Our aim was to study the diagnostic accuracy of LNSC measured with chemiluminescence assay in a prospective study, confirming discrepancies with mass spectrometry (MS). We enrolled 117 controls and 164 suspected CS (CS = 47, non-CS = 117). In case of increased LNSC, high clinical suspicion of CS or adrenal incidentaloma, patients were hospitalized to exclude/confirm CS. LNSC levels were higher in patients with suspected CS, CS, and non-CS than controls. Considering 16 nmol/L as threshold for CS, overall LNSC revealed SE 97% and SP 84% in the whole group of subjects considered, achieving positive/negative likelihood ratio of 5.56/0.045, respectively. 35 out of 81 subjects with increased LNSC were non-CS (15 diabetic and 20 obese): considering only those patients with increased likelihood to have a CS (the non-CS patients) SP decreased to 70%, and further reduced to 60% if we discharged subjects with adrenal incidentaloma. MS analyses reduced partially the number of false-positive LNSC. LNSC measured in automated chemiluminescence is reliable in clinical practice: it present a high diagnostic accuracy to exclude hypercortisolism in patients with normal cortisol levels. MS could be used to reduce the number of false-positive results; nevertheless, some non-CS subjects with functional hypercortisolism could have a mild impairment of cortisol rhythm.
- Published
- 2018