Saliva versus serum cortisol to identify subclinical hypercortisolism in adrenal incidentalomas: simplicity versus accuracy.

PURPOSE: Subclinical hypercortisolism (SCH) leads to metabolic derangements and increased cardiovascular risk. Cortisol autonomy is defined by the overnight 1 mg dexamethasone suppression test (DST). Saliva cortisol is an easier, stress-free, and cost-effective alternative to serum cortisol. We compared 23 h and post-1 mg DST saliva with serum cortisol to identify SCH in adrenal incidentalomas (AI). METHODS: We analyzed 359 DST obtained retrospectively from 226 AI subjects (173F/53 M; 19-83 years) for saliva and serum cortisol. We used three post-DST serum cortisol cutoffs to uncover SCH: 1.8, 2.5, and 5.0 µg/dL. We determined post-DST and 23 h saliva cortisol cutoffs by ROC curve analysis and calculated their sensitivities (S) and specificities (E). RESULTS: The sensitive 1.8 µg/dL cutoff defined 137 SCH and 180 non-functioning adenomas (NFA): post-DST and 23 h saliva cortisol S/E were: 75.2%/74.4% and 59.5%/65.9%, respectively. Using the specific 5.0 µg/dL cortisol cutoff (22 SCH/295 NFA), post-DST and 23 h saliva cortisol S/E were 86.4%/83.4% and 66.7%/80.4%, respectively. Using the intermediate 2.5 µg/dL cutoff (89 SCH/228 NFA), post-DST and 23 h saliva cortisol S/E were 80.9%/68.9% and 65.5%/62.8%, respectively. CONCLUSION: Saliva cortisol showed acceptable performance only with the 5.0 µg/dL cortisol cutoff, as in overt Cushing's syndrome. Lower cutoffs (1.8 and 2.5 µg/dL) that identify larger samples of patients with poor metabolic outcomes are less accurate for screening. These results may be attributed to pre-analytical factors and inherent patient conditions. Thus, saliva cortisol cannot replace serum cortisol to identify SCH among patients with AI for screening DST.

Zona fasciculata 21-hydroxysteroids and precursor-to-product ratios in 21-hydroxylase deficiency: further characterization of classic and non-classic patients and heterozygote carriers.

INTRODUCTION: Although much is known about the increased levels of the 21-hydroxylase substrates 17-hydroxyprogesterone (17OHP) and 21-deoxycortisol (21DF) - the biochemical markers of all forms of 21-hydroxylase deficiency (21OHD), only limited information is available on the zona fasciculata (ZF) products distal to the enzymatic block: 11-deoxycortisol (S), 11-deoxycorticosterone (DOC), and corticosterone (B). OBJECTIVE: To investigate whether basal and post-ACTH levels of S, DOC, and B and the 21-hydroxylase precursor-to-product ratios determined by tandem mass spectrometry preceded by high-performance liquid chromatography separation (liquid chromatography-tandem mass spectrometry) could disclose distinct profiles in genotypically confirmed classic (no.=14) and non-classic (NC) (no.=18) patients, heterozygote carriers (no.=61) and wildtypes (WT) (no.=27) for 21OHD. RESULTS: Salt wasting (SW) and simple virilizing (SV) had higher basal levels of DOC with no further increase in response to ACTH. Stimulated DOC was similar in 21OHD patients and carriers but was reduced as compared to WT. ACTH-stimulated B increased gradually from SW and SV through WT. The post-ACTH 21DF/B ratio was able to detect 92% of the carriers among WT. All NC patients could be detected by post-ACTH 17OHP/DOC and 21DF/B, with no overlap with 21OHD carriers. CONCLUSION: Although 21-hydroxylase is a key enzymatic step in both 17-hydroxy and 17-deoxy pathways of ZF, the reaction is mostly affected in the latter pathway, leading to a significant impairment of B production, which may further characterize the 21OHD subtypes. Also, the precursor-to-product ratios, particularly 21DF/B, can demonstrate the distinctive outline of 21OHD subtypes, including carriers and normal subjects.