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The diagnostic value of late-night salivary cortisol for diagnosis of subclinical Cushing’s syndrome
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Abstract
Introduction: Late-night salivary cortisol is a frequently used and easily implemented diagnostically valuable test for the diagnosis of overt Cushing’s syndrome. The use of late-night salivary cortisol in the diagnosis of subclinical Cushing’s syndrome is somewhat controversial. In this study, we aimed to determine the diagnostic value of late-night salivary cortisol in diagnosing subclinical Cushing’s syndrome and compare it with 24-hour urinary free cortisol levels (UFC).
Material and methods: The study consisted of 33 cases of subclinical Cushing’s syndrome, 59 cases of non-functioning adrenal adenoma, and 41 control subjects. Late-night salivary cortisol and UFC were measured in all the cases. The diagnosis of subclinical Cushing’s syndrome was based on combined results of 1 mg dexamethasone suppression test > 1.8 μg/dL and ACTH < 10 pg/mL.
Results: Mean late-night salivary cortisol levels in subjects with subclinical Cushing’s syndrome were significantly higher than in subjects with non-functioning adrenal adenoma and the control group (p < 0.001). Using a cut-off value of 0.18 μg/dL, the sensitivity and specificity of late-night salivary cortisol for diagnosing subclinical Cushing’s syndrome were determined as 82% and 60%, respectively. Using a cut-off value of 137 μg/day, the sensitivity and specificity of UFC was determined as 18% and 90%, respectively.
Conclusions: Because the sensitivity of late-night salivary cortisol for the diagnosis of subclinical Cushing’s syndrome is limited, using it as the sole screening test for subclinical Cushing’s syndrome may lead to false negative results. However, using it as an adjunct test to other tests may be beneficial in the diagnosis of subclinical Cushing’s syndrome. (Endokrynol Pol 2016; 67 (5): 487–492)
Abstract
Introduction: Late-night salivary cortisol is a frequently used and easily implemented diagnostically valuable test for the diagnosis of overt Cushing’s syndrome. The use of late-night salivary cortisol in the diagnosis of subclinical Cushing’s syndrome is somewhat controversial. In this study, we aimed to determine the diagnostic value of late-night salivary cortisol in diagnosing subclinical Cushing’s syndrome and compare it with 24-hour urinary free cortisol levels (UFC).
Material and methods: The study consisted of 33 cases of subclinical Cushing’s syndrome, 59 cases of non-functioning adrenal adenoma, and 41 control subjects. Late-night salivary cortisol and UFC were measured in all the cases. The diagnosis of subclinical Cushing’s syndrome was based on combined results of 1 mg dexamethasone suppression test > 1.8 μg/dL and ACTH < 10 pg/mL.
Results: Mean late-night salivary cortisol levels in subjects with subclinical Cushing’s syndrome were significantly higher than in subjects with non-functioning adrenal adenoma and the control group (p < 0.001). Using a cut-off value of 0.18 μg/dL, the sensitivity and specificity of late-night salivary cortisol for diagnosing subclinical Cushing’s syndrome were determined as 82% and 60%, respectively. Using a cut-off value of 137 μg/day, the sensitivity and specificity of UFC was determined as 18% and 90%, respectively.
Conclusions: Because the sensitivity of late-night salivary cortisol for the diagnosis of subclinical Cushing’s syndrome is limited, using it as the sole screening test for subclinical Cushing’s syndrome may lead to false negative results. However, using it as an adjunct test to other tests may be beneficial in the diagnosis of subclinical Cushing’s syndrome. (Endokrynol Pol 2016; 67 (5): 487–492)
Keywords
subclinical Cushing’s syndrome; salivary cortisol; urinary free cortisol; screening
About this articleTitle
The diagnostic value of late-night salivary cortisol for diagnosis of subclinical Cushing’s syndrome
Journal
Issue
Article type
Original paper
Pages
487-492
Published online
2016-01-22
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2390
Article views/downloads
2733
DOI
Pubmed
Bibliographic record
Endokrynol Pol 2016;67(5):487-492.
Keywords
subclinical Cushing’s syndrome
salivary cortisol
urinary free cortisol
screening
Authors
Idris Kuzu
Sayid Shafi Zuhur
Nazan Demir
Gokce Aktas
Feyza Yener Ozturk
Yuksel Altuntas
