Midnight salivary cortisol for the initial diagnosis of Cushing's syndrome of various causes

UP165, A Standardized Corn Leaf Extract for Improving Sleep Quality and Mood State

UP165, a standardized Zea mays (corn) leaf extract, was evaluated for its effect on sleep quality and overall well-being in a double-blind, placebo-controlled clinical trial, administered orally at 250 and 500 mg/day. Participants (n = 45) (age range 19-73) consumed the supplement or placebo ∼60 minutes before bedtime daily for 4 weeks. Measurements that were evaluated were as follows: daily sleep quality, as monitored by a fitness tracker; the Pittsburgh Sleep Quality Index (PSQI) for sleep quality and efficiency; salivary cortisol levels for stress; and Profile of Mood States (POMS) to assess general well-being. Participants who received UP165 showed a statistically significant and dose-correlated reduction in salivary cortisol (up to 36%); an increase in deep sleep time (up to 30 minutes); increased total sleep time (up to 10%); an improvement in sleep quality (up to 49%), and an enhanced POMS (36-58%). Participants in the UP165 group showed a sevenfold increase in deep sleep time and a 10-fold increase in PSQI sleep quality improvement compared to placebo. Collectively, UP165 is a safe nutritional supplement clinically proven for a 24-hour support with better quality and efficiency of sleep at night and an improved mood state and overall well-being during the day. The clinical study has been ISRCTN registered with study ID ISRCTN68282897.

Clinical, pathophysiologic, genetic and therapeutic progress in Primary Bilateral Macronodular Adrenal Hyperplasia

Patients with primary bilateral macronodular adrenal hyperplasia (PBMAH) usually present bilateral benign adrenocortical macronodules at imaging and variable levels of cortisol excess. PBMAH is a rare cause of primary overt Cushing's syndrome, but may represent up to one third of bilateral adrenal incidentalomas with evidence of cortisol excess. The increased steroidogenesis in PBMAH is often regulated by various G-protein coupled receptors aberrantly expressed in PBMAH tissues; some receptor ligands are ectopically produced in PBMAH tissues creating aberrant autocrine/paracrine regulation of steroidogenesis. The bilateral nature of PBMAH and familial aggregation, led to the identification of germline heterozygous inactivating mutations of the ARMC5 gene, in 20-25% of the apparent sporadic cases and more frequently in familial cases; ARMC5 mutations/pathogenic variants can be associated with meningiomas. More recently, combined germline mutations/pathogenic variants and somatic events inactivating the KDM1A gene were specifically identified in patients affected by GIP-dependent PBMAH. Functional studies demonstrated that inactivation of KDM1A leads to GIP-receptor (GIPR) overexpression and over or down-regulation of other GPCRs. Genetic analysis is now available for early detection of family members of index cases with PBMAH carrying identified germline pathogenic variants. Detailed biochemical, imaging, and co-morbidities assessment of the nature and severity of PBMAH is essential for its management. Treatment is reserved for patients with overt or mild cortisol/aldosterone or other steroid excesses taking in account co-morbidities. It previously relied on bilateral adrenalectomy; however recent studies tend to favor unilateral adrenalectomy, or less frequently, medical treatment with cortisol synthesis inhibitors or specific blockers of aberrant GPCR.

Sensitive and Robust LC-MS/MS Analysis of Salivary Cortisol in Negative Mode

Cortisol is one of the most important glucocorticoids involved in the regulation of human metabolism and physiological stress. Monitoring of levels of cortisol is of immense clinical benefit. In particular, salivary cortisol levels have been shown to correlate well with diurnal changes in cortisol levels in serum and have been used widely for monitoring of cortisol levels for diagnosis and prognosis purposes. We present a sensitive, fast, and robust quantitative liquid chromatography and tandem mass spectrometry (LC-MS/MS) assay for salivary cortisol in negative mode. This assay employs protein precipitation followed by reversed-phase liquid chromatographic separation, negative-mode electrospray ionization (ESI), and MS/MS detection. This assay has a total run time of 5.8 minutes and a limit of quantification of 0.5 ng/mL with a linear range up to 100 ng/mL. No carryover was observed at 10 μg/mL. This assay also incorporates the routine monitoring of prednisolone, a potential interferent to salivary cortisol.

Clinical and Technical Aspects in Free Cortisol Measurement

Accurate measurement of cortisol is critical in adrenal insufficiency as it reduces the risk associated with misdiagnosis and supports the optimization of stress dose. Comprehensive assays have been developed to determine the levels of bioactive free cortisol and their clinical and analytical efficacies have been extensively discussed because the level of total cortisol is affected by changes in the structure or circulating levels of corticoid-binding globulin and albumin, which are the main reservoirs of cortisol in the human body. Antibody-based immunoassays are routinely used in clinical laboratories; however, the lack of molecular specificity in cortisol assessment limits their applicability to characterize adrenocortical function. Improved specificity and sensitivity can be achieved by mass spectrometry coupled with chromatographic separation methods, which is a cutting-edge technology to measure individual as well as a panel of steroids in a single analytical run. The purpose of this review is to introduce recent advances in free cortisol measurement from the perspectives of clinical specimens and issues associated with prospective analytical technologies.

Consensus statement by the French Society of Endocrinology (SFE) and French Society of Pediatric Endocrinology & Diabetology (SFEDP) on diagnosis of Cushing's syndrome

Cushing's syndrome is defined by prolonged exposure to glucocorticoids, leading to excess morbidity and mortality. Diagnosis of this rare pathology is difficult due to the low specificity of the clinical signs, the variable severity of the clinical presentation, and the difficulties of interpretation associated with the diagnostic methods. The present consensus paper by 38 experts of the French Society of Endocrinology and the French Society of Pediatric Endocrinology and Diabetology aimed firstly to detail the circumstances suggesting diagnosis and the biologic diagnosis tools and their interpretation for positive diagnosis and for etiologic diagnosis according to ACTH-independent and -dependent mechanisms. Secondly, situations making diagnosis complex (pregnancy, intense hypercortisolism, fluctuating Cushing's syndrome, pediatric forms and genetically determined forms) were detailed. Lastly, methods of surveillance and diagnosis of recurrence were dealt with in the final section.

Cyclic Cushing's Syndrome - A Diagnostic Challenge

Cyclic Cushing's syndrome (also known as intermittent or periodic) is a disease characterized by periods of transient hypercortisolemia shifting into periods of normo- and/or hypocortisolemia. Diagnosis of cyclic Cushing's syndrome is based on at least three periods of confirmed hypercortisolemia interspersed by two periods of normocortisolemia. Cyclic Cushing's syndrome is one of the greatest challenges in modern endocrinology due to its diverse clinical picture, unpredictable duration and frequency of phases, and various etiologies. We discuss a diagnostic algorithm for periodic hypercortisolemia with special regard to hair cortisol analysis and desmopressin stimulation test which both seem to be helpful in finding the correct answer.

Biochemical diagnosis of Cushing's disease: Screening and confirmatory testing

Due to the variable clinical features and its rarity diagnosis of Cushing's disease (CD) is often delayed. Clearly, awareness for CD needs to be raised, accompanied by the availability of simple and accurate screening tests. Late-night salivary cortisol (LNSC), 1 mg dexamethasone suppression test (DST), and urinary free cortisol (UFC) have all been extensively studied, demonstrating high sensitivity and specificity for the diagnosis of Cushing's syndrome. However, each of those well-established tests has its own distinctive features, making it preferable in specific clinical conditions and patient groups. To choose the most appropriate test in individual patients, an expert endocrinologist should be consulted. This review will discuss the pitfalls for each of those tests.

Diabetes, Active Disease, and Afternoon Serum Cortisol Levels Predict Cushing's Disease Mortality: A Cohort Study

CONTEXT

Cushing's disease (CD) is a life-threating disease, with increased mortality in comparison with the general population.

OBJECTIVE

This study aimed to evaluate standardized mortality ratios (SMRs) in CD patients. We also analyzed independent risk factors related to increased mortality.

DESIGN

We conducted a longitudinal cohort study in a 3rd level specialty center, from 1979 to 2018, in patients with CD.

RESULTS

From 1375 cases with a pathology diagnosis of pituitary adenoma, 191 cases had the confirmed diagnosis of CD (14%). A total of 172 patients completed follow-up, with a mean age at diagnosis of 33 ± 11 years, female predominance (n = 154, 89.5%), majority of them with microadenoma (n = 136, 79%), and a median follow-up of 7.5 years (2.4-15). Eighteen patients (10.5%) died, 8 of them (44%) were with active CD, 8 (44%) were under remission, and 2 (11%) were under disease control. Estimated all-cause SMR = 3.1, 95% confidence interval (CI) 1.9-4.8, P < 0.001. Cardiovascular disease was the main cause of death (SMR = 4.2, 1.5-9.3, P = 0.01). Multivariate Cox regression models adjusted for potential cofounders showed that diabetes (HR = 5.2, IC 95% 1.8-15.4, P = 0.002), high cortisol levels after 1600 hours at diagnosis (3.4, 2.3-7.0, P = 0.02), and active CD (7.5, 3.8-17.3, P = 0.003) significantly increased the risk of mortality.

CONCLUSIONS

Main cause of CD mortality was cardiovascular disease. Main risk factors for mortality were uncontrolled diabetes, persistently high cortisol levels after 1600 hours at diagnosis, and active disease at last follow-up.

Cortisol Measurements in Cushing's Syndrome: Immunoassay or Mass Spectrometry?

Determination of cortisol levels in the urine (24 hours urine free cortisol), saliva (late-night), or serum (total cortisol after dexamethasone suppression) is recommended to screen for Cushing's syndrome (CS). This review focuses on the differences between the frequently used cortisol-antibody immunoassay-based methods and the highly specific mass-spectrometry-based methods that are progressively being employed in clinical laboratories for CS screening. The particular characteristics of cortisol metabolism and the lack of specificity of the immunoassays cause marked differences between both methods that are in turn highly dependent on the biological matrix, in which the cortisol is measured. Understanding the origin of these differences is essential for the interpretation of these results. Although cross-reactivity with endogenous steroids leads to grossly inaccurate results of immunoassay measurements of cortisol in the saliva and urine, preliminary evidence suggests that the clinical sensitivity of CS screening using immunoassays may be similar to CS screening using mass spectrometry. However, mass spectrometry offers more accurate results and considerably reduced variation across laboratories, while avoiding false-positive results. Moreover, mass spectrometry can overcome some common diagnostic challenges, such as identification of exogenous corticosteroids or simultaneous assessment of appropriate dexamethasone levels in suppression tests. Further, comprehensive mass spectrometry-based profiling of several steroid metabolites may be useful for discriminating among different subtypes of CS. Finally, this review discusses the main preanalytical factors that could cause variations in cortisol measurements and their influence on the reliability of the results.

The diagnostic utility of late night salivary cortisol (LNSF) and cortisone (LNSE) in Cushing's syndrome

BACKGROUND

Measurement of late night salivary cortisol (LNSF) is useful in the identification of cyclical Cushing's syndrome (CS); the usefulness of its metabolite cortisone (late night salivary cortisone, LNSE) is less well described.

AIM

The aim of this study was to determine the utility of measuring LNSE in patients with confirmed CS compared with other diagnostic tests and to analyse serial LNSF measurements for evidence of variable hormonogenesis.

METHODS

This was a retrospective observational study including patients with confirmed CS in whom LNSF and LNSE were measured.

RESULTS

Twenty-three patients with confirmed CS were included, 21 with Cushing's disease. LNSF had a sensitivity of 92%, LNSE 87% and combined LNSF/LNSE 94% per sample. Four patients had cyclical hormonogenesis, when the definition of one trough and two peaks was applied to LNSF measurements, and a fifth patient fell just outside the criteria. Six patients had evidence of variable hormonogenesis, defined as doubling of LNSF concentration on serial measurements. Sensitivity of 24-h urinary free cortisol (UFC) was 89% per collection. Sixteen patients had simultaneous measurements of LNSF and UFC; in three patients, they provided discordant results.

CONCLUSION

LNSF appears more sensitive than LNSE and UFC in the diagnosis of CS, combining LNSF and LNSE results leads to superior sensitivity. Half of our cohort had evidence of cyclical or variable hormonogenesis. Fluctuations in LNSF did not always correlate with changes in UFC concentration, emphasising the importance of performing more than one screening test, particularly if pretest clinical suspicion is high.

Late-Night Salivary Cortisol in Healthy, Community-Dwelling Asian Indians Assessed by Second-Generation ECLIA

BACKGROUND

Late-night salivary cortisol (LNSC) is used as a screening test for Cushing syndrome (CS), but there is no community-derived normative data for the normal upper limit in the South Asian population. This study aimed to determine the upper limit of normal (97.5th percentile) for LNSC in an Asian Indian population using a commercially available second-generation electrochemiluminiscence immunoassay (ECLIA).

METHODS

LNSC in apparently healthy community-dwelling individuals was assessed by multistage cluster sampling. Healthy individuals age 18 to 60 years from 8 urban and 8 rural clusters of Thiruvananthapuram district were studied. Thirty people from an approximate population of 1000 individuals from each cluster participated in the study. A saliva sample was collected between 11 PM and 12 midnight and analyzed using Roche COBAS-e-411 and ultrasensitive Cortisol II kits the next day.

RESULTS

Cortisol values from 474 salivary samples were available for final analysis after exclusion of improperly collected samples. The 97.5th percentile of the LNSC concentrations was 0.25 μg/dL (6.89 nmol/L) (90% CI, 0.23-0.27 μg/dL; ie, 6.34-7.45 nmol/L). In postmenopausal women, median LNSC was significantly higher but the 90% CI for the upper limit of their LNSC (0.28μg/dL or 7.72 nmol/L) overlapped with that of premenopausal women.

CONCLUSIONS

This study establishes the normal value of LNSC estimated by second-generation ECLIA in healthy community-dwelling Asian Indian individuals for the first time. Salivary cortisol at 11 pm to 12 am is less than 0.25μg/dL (6.89 nmol/L) in the general Asian Indian population. Menopause causes a significant increase in LNSC and may lead to overdiagnosis of CS if not interpreted carefully.

Accuracy of Laboratory Tests for the Diagnosis of Cushing Syndrome

CONTEXT

The diagnosis of Cushing syndrome (CS) can be challenging. It remains to be determined which diagnostic tests are the most accurate.

OBJECTIVE

To summarize the accuracy of diagnostic tests for CS using contemporary meta-analytic techniques (hierarchical models).

DATA SOURCES

PubMed, Embase, Scopus, Web of Science, and the Cochrane Database of Systemic Reviews (inception until August 3, 2018).

STUDY SELECTION

Studies performed in adults that determined the accuracy of one or more diagnostic tests: overnight 1-mg dexamethasone suppression test (DST), 2-day low-dose DST (2d DST), 24-hour urinary free cortisol (UFC), late-night salivary cortisol (LNSC), midnight serum cortisol (MSC), and the dexamethasone-suppressed CRH (dex-CRH) and desmopressin (dex-DDAVP) tests.

DATA EXTRACTION

Two authors independently extracted data and performed methodological assessments.

DATA SYNTHESIS

One hundred thirty-nine studies (14 140 participants) were included in the analysis. The respective sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio (95% confidence interval [CI]) estimates include the following: DST 98.6% (96.9%-99.4%), 90.6% (86.4%-93.6%), 10.5 (7.2-15.3), and 0.016 (0.007-0.035); 2d DST 95.3% (91.3%-97.5%), 92.8% (85.7%-96.5%), 13.2 (6.47-27.1), and 0.051 (0.027-0.095); UFC 94.0% (91.6%-95.7%), 93.0% (89.0%-95.5%), 13.3 (8.47-21.0), and 0.065 (0.046-0.092); LNSC 95.8% (93.%-97.2%), 93.4% (90.7%-95.4%), 14.6 (10.3-20.7), and 0.045 (0.030-0.066); MSC 96.1% (93.5%-97.6%), 93.2% (88.1%-96.3%), 14.2 (7.96-25.2), and 0.042 (0.026-0.069); and dex-CRH 98.6% (90.4%-99.8%), 85.9% (67.6%-94.7%), 7.0 (2.80-17.6), and 0.016 (0.002-0.118). A single study evaluated dex-DDAVP. Meta-regression and a novel network meta-analytic approach suggest that DST is the most sensitive while UFC is the least sensitive.

CONCLUSIONS

All of the included diagnostic tests for CS are highly sensitive and specific. It appears that the DST is the most sensitive while the UFC is less sensitive. The specificity of all first-line tests appears comparable.

Cushing's syndrome: Overview of clinical presentation, diagnostic tools and complications

Cushing's syndrome (CS) is a severe condition that results from chronic exposure to elevated circulating cortisol levels; it is a rare but potentially life-threating condition, especially when not timely diagnosed and treated. Even though the diagnosis can be straightforward in florid cases due to their typical phenotype, milder forms can be missed. Despite the availability of different screening tests, the diagnosis remains challenging as none of the available tools proved to be fully accurate. Due to the ubiquitous effect of cortisol, it is easy understandable that its excess leads to a variety of systemic complications including hypertension, metabolic syndrome, bone damages and neurocognitive impairment. This article discusses clinical presentation of CS with an eye on the most frequent cortisol-related comorbidities and discuss the main pitfalls of first- and second-line tests in endogenous hypercortisolism diagnostic workup.

Salivary and serum biomarkers of inflammation in a man with metastatic medullary thyroid carcinoma and hyperreactive gingiva: a fourteen year odyssey

A peripheral (gingival) fibroma, a gingival cyst and hyperplastic gingivitis occurred simultaneously in a man with metastatic medullary thyroid carcinoma (MCT). The gingival growths and hyperplasia appeared to be related to poor oral hygiene rather than to the MTC. Despite the patient's improved oral hygiene, the hyperplastic gingivitis and peripheral fibroma recurred, and a new peripheral fibroma and gingival cyst developed, which prompted reconsideration of a link with the MTC. MTC cells secrete calcitonin (CT), procalcitonin (ProCT) and growth factors; the patient's serum CT and ProCT were several fold higher than normal. The patient's salivary CT and ProCT also were elevated, but α-amylase and epidermal growth factor (EGF) were not, compared to three healthy controls. A possible link between the MTC and gingival hyper-reactivity due to CT and/or ProCT promoting inflammatory cytokines, and the utility of salivary ProCT as an indicator of periodontitis in this patient were explored further. Unstimulated whole saliva and serum were collected from the patient followed by a standard periodontal examination before periodontal treatment, and 3 weeks and 3 months after treatment. This cycle was repeated 7 months after the previous periodontal treatment. The saliva was assayed for ProCT and the serum was assayed for ProCT, high sensitivity C-reactive protein (CRP), interleukin-6 (IL-6) and proadrenomedullin (ProADM). The results were analyzed for correlations among the severity of periodontitis and the biomarkers/cytokines. Only the salivary ProCT was correlated with the severity of periodontitis, i.e. it was higher just before and lower at 3 weeks and 3 months after each periodontal treatment. The patient's salivary ProCT content also was much higher than reported elsewhere. The other biomarkers/cytokines were within normal ranges. Our findings indicate that salivary ProCT is independent of serum ProCT and therefore may be a useful marker for moderate to severe periodontitis in patients with MTC. The greatly elevated salivary and serum CT and ProCT, and a trend toward correlation between the serum CRP and ProCT suggest a pro-inflammatory link between the MTC and the hyperreactive gingiva in this patient. Further studies are warranted to determine whether hyperplastic gingivitis and gingival growths, such as cysts and fibromas, occur with unusual frequency in patients with MTC.

A successful pregnancy in a patient with secondary hypertension caused by adrenal adenoma: a case report

Background

Secondary hypertension is a rare complication in pregnancy that causes poor outcomes, such as preeclampsia, premature delivery, intrauterine growth retardation, stillbirths, spontaneous abortion or intrauterine death. Cushing’s disease caused by an adrenal adenoma is rare during pregnancy and may be overlooked by obstetricians and physicians, but can lead to hypertension, diabetes mellitus and an increased risk of fetal and maternal morbidity. Approximately 200 cases have been reported in the literature. Here, we report the successful management of a pregnant patient with Cushing’s syndrome due to an adrenal adenoma.

Case presentation

The 35-year-old Chinese female had no individual or family medical history of hypertension, and did not exhibit chronic kidney disease, diabetes mellitus, autoimmune and common endocrine diseases. Her blood pressure was elevated from the 16th week of gestation and was not controlled by 30 mg nifedipine twice a day. Examination in our department revealed her 24 h urinary free cortisol (24 h UFC) level was 1684.3 μg/24 h (normal range: 20.26–127.55 μg/24 h) and plasma adrenocorticotropic hormone was < 1.00 ng/L in three independent measurements (normal range: 5–78 ng/L). Ultrasonography demonstrated a mass (2.9 cm × 2.8 cm) in the right side of the adrenal gland. Magnetic resonance imaging without contrast showed a 3.2 cm diameter mass in the right-side of the adrenal gland. Other medical tests were normal. Laparoscopic adrenalectomy was performed at the 26th week of gestation by a urological surgeon in the West China Hospital. Histopathology revealed an adrenocortical adenoma. After surgery, the patient accepted glucocorticoid replacement therapy. The remaining trimester continued without complication and her blood pressure was normal at the 32nd week of gestation without antihypertensive therapy. The patient gave birth to a healthy boy at the 40th week of gestation.

Conclusions

Cushing’s syndrome caused by adrenal adenoma is rare during pregnancy. This unique case suggested that analysis of the UFC level and circadian rhythm of plasma cortisol provides a suitable strategy to diagnose Cushing’s syndrome during pregnancy. Laparoscopic surgical resection in the second trimester provides a reasonable approach to treat pregnant patients exhibiting Cushing’s syndrome caused by an adrenal adenoma.

Midnight salivary cortisol for the diagnosis of Cushing's syndrome in a Chinese population

INTRODUCTION

Cushing's syndrome is defined as chronic excess free cortisol in circulation. According to recent studies, midnight salivary cortisol is an accurate and non-stress method for screening and diagnosing Cushing's syndrome. However, there is limited data on midnight salivary cortisol for diagnosing Cushing's syndrome in the Chinese population.

METHODS

Among 61 suspected Chinese patients, 48 patients were confirmed to have Cushing's syndrome. We evaluated the midnight salivary cortisol, midnight serum cortisol and 24-hour urine free cortisol excretion for diagnosis. Midnight salivary cortisol was collected from 21 healthy volunteers for control purposes.

RESULTS

In the patient group, mean urine free cortisol excretion and midnight salivary cortisol levels were 296.50 ± 47.99 µg/day and 10.18 ± 1.29 ng/mL, respectively. Among the control group and normal participants, mean midnight salivary cortisol level was 0.53 ± 0.13 ng/mL and 0.50 ± 0.12 ng/mL, respectively. The cut-off value for midnight salivary cortisol was 1.7 ng/mL for diagnosing Cushing's syndrome, with a sensitivity of 98% and specificity of 100%. The diagnostic performance of midnight salivary cortisol (area under the curve [AUC] = 0.99) was superior to that of urine free cortisol (AUC = 0.89).

CONCLUSION

Our study confirmed the good diagnostic performance of midnight salivary cortisol for diagnosing Cushing's syndrome in a Chinese population. Correlation between midnight salivary cortisol and either urine free cortisol or midnight serum cortisol was good. Midnight salivary cortisol is a convenient and precise tool for diagnosing Cushing's syndrome and can be the screening test of choice for Chinese populations.

A variable course of Cushing's disease in a 7 year old: diagnostic dilemma

Background Cushing's syndrome (CS) or hypercortisolism results from disruption of the hypothalamus-pituitary-adrenal (HPA) axis with the resultant increase in the circulating serum and urinary cortisol levels and lack of cortisol circadian rhythm. The resultant effects cause the physical manifestation of hypercortisolism. The appearance of Cushing's disease in children is insidious, the most common features being growth failure, obesity, early puberty and facial appearance. Case presentation We report a case of a 7-year-old male with a very unusual course of the disease, which could have led to diagnostic delays.

Diagnostic value of the late-night salivary cortisol in the diagnosis of clinical and subclinical Cushing’s syndrome: results of a single-center 7-year experience

Late-night salivary cortisol (LNSaC) is an easy-to-use test reflecting the free cortisol level in the serum and does not require hospitalization. Controlled studies reported that LNSaC has a high sensitivity and specificity, but have not set a clearly defined cut-off value to be used in the diagnosis of Cushing’s syndrome. In this study, we aimed to evaluate the diagnostic performance of LNSaC in patients with clinical Cushing’s syndrome (CCS) and subclinical Cushing’s syndrome (SCS). The data of 543 patients, whose LNSaC levels were assessed using electrochemiluminescence immunoassay method, were retrospectively evaluated. The study included a total of 324 patients: 58 patients with CCS, 53 patients with SCS, and 213 patients without Cushing’s syndrome (NoCS). The cause of the Cushing’s syndrome was hypophyseal in 26 patients (45%), adrenal in 24 patients (41%), and ectopic in 8 patients (14%) in the CCS group. Median LNSaC levels were 0.724 (0.107–33) µg/dL in CCS group, 0.398 (0.16–1.02) µg/dL in SCS group, and 0.18 (0.043–0.481) µg/dL in NoCS group (p=0.001). Accordingly, LNSaC had 89.6% sensitivity and 81.6% specificity at a cut-off value of 0.288 µg/dL in the diagnosis of CCS; and had 80.7% sensitivity and 85.1% specificity at a cut-off value of 0.273 µg/dL in the diagnosis of SCS. In the present study, a lower sensitivity and specificity than previously reported was found for LNSaC in the diagnosis of CCS. Moreover, the diagnostic performance of LNSaC in patients with SCS was close to its diagnostic performance in patients with CCS. Each center should determine its own cut-off value based on the method adopted for LNSaC measurement, and apply that cut-off value in the diagnosis of Cushing’s syndrome.

MECHANISMS IN ENDOCRINOLOGY: A sense of time of the glucocorticoid circadian clock: from the ontogeny to the diagnosis of Cushing's syndrome

The circadian rhythm of glucocorticoids has long been recognised within the last 75 years. Since the beginning, researchers have sought to identify basic mechanisms underlying the origin and emergence of the corticosteroid circadian rhythmicity among mammals. Accordingly, Young, Hall and Rosbash, laureates of the 2017 Nobel Prize in Physiology or Medicine, as well as Takahashi's group among others, have characterised the molecular cogwheels of the circadian system, describing interlocking transcription/translation feedback loops essential for normal circadian rhythms. Plasma glucocorticoid circadian variation depends on the expression of intrinsic clock genes within the anatomic components of the hypothalamic-pituitary-adrenal axis, which are organised in a hierarchical manner. This review presents a general overview of the glucocorticoid circadian clock mechanisms, highlighting the ontogeny of the pituitary-adrenal axis diurnal rhythmicity as well as the involvement of circadian rhythm abnormalities in the physiopathology and diagnosis of Cushing's disease.

Clinical utility of an ultrasensitive late night salivary cortisol assay by tandem mass spectrometry

BACKGROUND

Late night salivary cortisol measurement is a clinically important and convenient screening test for Cushing's syndrome. Tandem mass spectrometry (LC-MS/MS) assays have superior sensitivity and specificity compared to immunoassays. Our goal was to improve a LC-MS/MS method to measure salivary cortisol in both adult and pediatric patients and to characterize its analytical performance by method validation and clinical performance by chart review.

METHODS

We improved a LC-MS/MS method originally developed for urine cortisol to measure low level salivary cortisol. The sample preparation was by liquid-liquid extraction using dichloromethane followed by stepwise washing with acidic, basic and neutral solutions. The assay's analytical performance was characterized and retrospective patient chart review was conducted to evaluate the assay's clinical diagnostic performance.

RESULTS

The LC-MS/MS assay showed enhanced functional sensitivity of 10 ng/dL for salivary cortisol and was linear within an analytical measurement range of 10-10,000 ng/dL. Assay accuracy was within 84-120% as determined by recovery studies and correlation with a reference method. Data from healthy adult volunteers was compiled to establish the reference interval for late night salivary cortisol. Patient chart review determined subjects with diagnosis of Cushing's syndrome or disease, and assay's clinical diagnostic sensitivity of 100% and specificity of 92% when the cutoff value was 70 ng/dL.

CONCLUSIONS

The improved LC-MS/MS method is sensitive and specific with enhanced analytical performance and clinical diagnostic utility for screening Cushing's syndrome. The assay may have broad clinical application due to its high sensitivity and wide dynamic range.

Cyclical Cushing's: how best to catch the ups and downs

A 68-year-old man with a background of hypertension and type 2 diabetes presented with fluctuating symptoms of muscle aches and pains and tiredness. His initial work-up for the possibility of hypercortisolaemia showed a completely variable pattern, with 24-hour cortisol excretion and serum cortisol post 1 mg dexamethasone suppression test ranging from normal to significantly elevated. A series of salivary cortisol with symptom diary confirmed the cyclical nature of hypercortisolaemia, and his concomitant adrenocorticotropic hormone (ACTH) levels were elevated. An inferior petrosal sinus sampling, performed during hypercortisolaemic phase of his cycle,suggested a central source of ACTH secretion. He had unsuccessful exploration of his pituitary and was eventually treated with bilateral adrenalectomy followed by lifelong steroid replacement. His symptoms improved immediately, and he came off his oral hypoglycaemic and antihypertensive agents within 6 months following his surgery.

Multicenter performance evaluation of a second generation cortisol assay

Background:

Untreated disorders of the adrenocortical system, such as Cushing’s or Addison’s disease, can be fatal, and accurate quantification of a patient’s cortisol levels is vital for diagnosis. The objective of this study was to assess the analytical performance of a new fully-automated Elecsys® Cortisol II assay (second generation) to measure cortisol levels in serum and saliva.

Methods:

Four European investigational sites assessed the intermediate precision and reproducibility of the Cortisol II assay (Roche Diagnostics) under routine conditions. Method comparisons of the Cortisol II assay vs. liquid chromatography-tandem mass spectrometry (LC-MS/MS), the gold standard for cortisol measurement, were performed. Cortisol reference ranges from three US sites were determined using samples from self-reported healthy individuals.

Results:

The coefficients of variation (CVs) for repeatability, intermediate precision, and reproducibility for serum samples were ≤2.6%, ≤5.8%, and ≤9.5%, respectively, and for saliva were ≤4.4% and ≤10.9%, and ≤11.4%, respectively. Agreement between the Cortisol II assay and LC-MS/MS in serum samples was close, with a slope of 1.02 and an intercept of 4.473 nmol/L. Reference range samples were collected from healthy individuals (n=300) and serum morning cortisol concentrations (5–95th percentile) were 166.1–507 nmol/L and afternoon concentrations were 73.8–291 nmol/L. Morning, afternoon, and midnight saliva concentrations (95th percentile) were 20.3, 6.94, and 7.56 nmol/L, respectively.

Conclusions:

The Cortisol II assay had good precision over the entire measuring range and had excellent agreement with LC-MS/MS. This test was found suitable for routine diagnostic application and will be valuable for the diagnosis of adrenocortical diseases.

Diagnostic tests for Cushing's syndrome differ from published guidelines: data from ERCUSYN

OBJECTIVE

To evaluate which tests are performed to diagnose hypercortisolism in patients included in the European Registry on Cushing's syndrome (ERCUSYN), and to examine if their use differs from the current guidelines.

PATIENTS AND METHODS

We analyzed data on the diagnostic tests performed in 1341 patients with Cushing's syndrome (CS) who have been entered into the ERCUSYN database between January 1, 2000 and January 31, 2016 from 57 centers in 26 European countries. Sixty-seven percent had pituitary-dependent CS (PIT-CS), 24% had adrenal-dependent CS (ADR-CS), 6% had CS from an ectopic source (ECT-CS) and 3% were classified as having CS from other causes (OTH-CS).

RESULTS

Of the first-line tests, urinary free cortisol (UFC) test was performed in 78% of patients, overnight 1 mg dexamethasone suppression test (DST) in 60% and late-night salivary cortisol (LSaC) in 25%. Use of LSaC increased in the last five years as compared with previous years (P < 0.01). Use of HDDST was slightly more frequent in the last 5 years as compared with previous years (P < 0.05). Of the additional tests, late-night serum cortisol (LSeC) was measured in 62% and 48-h 2 mg/day low-dose dexamethasone suppression test (LDDST) in 33% of cases. ACTH was performed in 78% of patients. LSeC and overnight 1 mg DST supported the diagnosis of both PIT-CS and ADR-CS more frequently than UFC (P < 0.05).

CONCLUSIONS

Use of diagnostic tests for CS varies across Europe and partly differs from the currently available guidelines. It would seem pertinent that a European consensus be established to determine the best diagnostic approach to CS, taking into account specific inter-country differences with regard to the availability of diagnostic tools.

Influence of age, gender and body mass index on late-night salivary cortisol in healthy adults

Background:

Late-night salivary cortisol (LNSC) is one of the most reliable tests to screen for endogenous Cushing syndrome. This test is simple, inexpensive and noninvasive and has high sensitivity and specificity. The aim of our study was to analyze the putative influence of age, gender and body mass index (BMI) on LNSC levels in a healthy population.

Methods:

Cross-sectional study conducted in healthy adults. Midnight saliva samples were collected at home. Participants refrained from teeth brushing, eating or drinking for 2 h prior to collection. Salivary cortisol measured by electrochemiluminescence immunoassay (ECLIA). The study was approved by the Ethics Committee of the hospital (number 140073).

Results:

We evaluated 122 nonsmoking healthy volunteers. Mean age was 35±14 years (range, 18–74 years); 63% were women. Mean BMI was 24±3 kg/m

Conclusions:

The maximum reference value (P97.5) of LNSC was set at 8.3 nmol/L (0.3 μg/dL) using ECLIA. Advanced age was associated with higher LNSC levels, with no evident influence of gender or BMI.

Hypertension: The role of biochemistry in the diagnosis and management

Hypertension is defined as a persistently elevated blood pressure ≥140/90mmHg. It is an important treatable risk factor for cardiovascular disease, with a high prevalence in the general population. The most common cause, essential hypertension, is a widespread disease - however, secondary hypertension is under investigated and under diagnosed. Collectively, hypertension is referred to as a "silent killer" - frequently it displays no overt symptomatology. It is a leading risk factor for death and disability globally, with >40% of persons aged over 25 having hypertension. A vast spectrum of conditions result in hypertension spanning essential through resistant, to patients with an overt endocrine cause. A significant number of patients with hypertension have multiple cardiovascular risk factors at the time of presentation. Both routine and specialised biochemical investigations are paramount for the evaluation of these patients and their subsequent management. Biochemical testing serves to identify those hypertensive individuals who are at higher risk on the basis of evidence of dysglycaemia, dyslipidaemia, renal impairment, or target organ damage and to exclude identifiable causes of hypertension. The main target of biochemical testing is the identification of patients with a specific and treatable aetiology of hypertension. Information gleaned from biochemical investigation is used to risk stratify patients and tailor the type and intensity of subsequent management and treatment. We review the approach to the biochemical investigation of patients presenting with hypertension and propose a diagnostic algorithm for work-up.

Low positive predictive value of midnight salivary cortisol measurement to detect hypercortisolism in type 2 diabetes

BACKGROUND

Hypercortisolism is prevalent in type 2 diabetes (T2D), but analytical and functional uncertainties prevail. Measurement of salivary cortisol is considered an expedient screening method for hypercortisolism, but its usefulness in the context of T2D is uncertain.

AIM

To compare late-night salivary cortisol (LNSC) with the 1 mg overnight dexamethasone suppression test (DST), which was considered 'reference standard', in T2D.

PATIENTS AND METHODS

A total of 382 unselected and recently diagnosed patients with T2D underwent assessment of LNSC and DST, and the test outcome was related to age, gender, body mass index (BMI) and haemoglobin A1c levels. We used the following cut-off values: LNSC ≤ 3·6 nmol/l and DST ≤ 50 nmol/l.

RESULTS

The median (range) levels of LNSC and DST were 6·1 (0·3-46·2) nmol/l and 34 (11-547) nmol/l, respectively. Hypercortisolism was present in 86% based on LNSC values and 22% based on DST. LNSC, as compared to DST, had the following test characteristics: sensitivity: 85% (95% CI: 7-92%), specificity: 14% (95% CI: 10-19%), positive predictive value: 22% (95% CI: 17-27%), negative predictive value: 76% (95% CI: 63-87%), and overall accuracy: 30% (95% CI: 25-34%). LNSC and DST values were not associated with haemoglobin A1c, BMI and age in this cohort of patients with T2D.

CONCLUSION

The LNSC is characterized by very low specificity and poor positive predictive value as compared to the DST, resulting in an overall low accuracy. Further methodological and clinical studies are needed to substantiate the relevance of cortisol status in T2D.

Increased glycogen synthase kinase-3β and hexose-6-phosphate dehydrogenase expression in adipose tissue may contribute to glucocorticoid-induced mouse visceral adiposity

BACKGROUND

Increased adiposity in visceral depots is a crucial feature associated with glucocorticoid (GC) excess. The action of GCs in target tissue is regulated by GC receptor (GR) and 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) coupled with hexose-6-phosphate dehydrogenase (H6pdh). Glycogen synthase kinase-3β (GSK3β) is known to be a crucial mediator of ligand-dependent gene transcription. We hypothesized that the major effects of corticosteroids on adipose fat accumulation are in part medicated by changes in GSK3β and H6pdh.

METHODS

We characterized the alterations of GSK3β and GC metabolic enzymes, and determined the impact of GR antagonist mifepristone on obesity-related genes and the expression of H6pdh and 11ß-HSD1 in adipose tissue of mice exposed to excess GC as well as in in vitro studies using 3T3-L1 adipocytes treated with GCs.

RESULTS

Corticosterone (CORT) exposure increased abdominal fat mass and induced expression of lipid synthase ACC and ACL with activation of GSK3β phosphorylation in abdominal adipose tissue of C57BL/6J mice. Increased pSer⁹ GSK3β was correlated with induction of H6pdh and 11ß-HSD1. Additionally, mifepristone treatment reversed the production of H6pdh and attenuated CORT-mediated production of 11ß-HSD1 and lipogenic gene expression with reduction of pSer⁹ GSK3β, thereby leading to improvement of phenotype of adiposity within adipose tissue in mice treated with excess GCs. Suppression of pSer⁹ GSK3β by mifepristone was accompanied by activation of pThr³⁰⁸ Akt and blockade of CORT-induced adipogenic transcriptor C/EBPα and PPARγ. In addition, mifepristone also attenuated CORT-mediated activation of IRE1α/XBP1. Additionally, reduction of H6pdh by shRNA showed comparable effects to mifepristone on attenuating CORT-induced expression of GC metabolic enzymes and improved lipid accumulation in vitro in 3T3-L1 adipocytes.

CONCLUSION

These findings suggest that elevated adipose GSK3β and H6pdh expression contribute to 11ß-HSD1 mediating hypercortisolism associated with visceral adiposity.

Quantitative Analysis of Salivary Cortisol Using LC-MS/MS

Cortisol is one of the most important glucocorticoids and plays important roles in regulating human metabolism. Midnight salivary cortisol has been shown to correlate well with free cortisol concentration in serum and is one of the first tests recommended for the diagnosis of Cushing's syndrome.The procedure described here involves centrifugation of the saliva samples to remove solids and mucus strands before they are diluted with buffer and mixed with deuterated internal standard D4-cortisol. The samples are then subjected to reverse phase separation on a C18 column and analyzed by a tandem mass spectrometry method (LC-MS/MS). Quantification is achieved by comparing the responses of a given sample to the responses of the calibrators of known concentrations. The calibrators are prepared and analyzed along with the patient samples. Analytical specificity is ensured by using multiple reaction monitoring with fragment ions that are unique to cortisol and deuterated internal standard.

The morning and late-night salivary cortisol ranges for healthy women may be used in pregnancy

OBJECTIVES

The diagnosis of adrenal dysfunction in pregnancy and in women taking oral contraceptives remains a diagnostic challenge. Salivary cortisol seems to be a useful tool for the diagnosis of Cushing's syndrome and adrenal insufficiency. However, the changes in salivary cortisol concentration in healthy pregnancy are not clearly defined.

DESIGN

The aim of our study was to compare diurnal changes in salivary cortisol in healthy pregnant women, healthy controls and women on oral contraceptives.

PATIENTS

The study groups consisted of (i) 41 healthy pregnant women, (ii) 42 healthy women and (iii) 12 healthy women on oral contraceptives.

MEASUREMENTS

Serum and salivary cortisol in the morning and salivary late-night cortisol were measured with Roche ECLIA cortisol test (Elecsys 2010) in each trimester and postpartum.

RESULTS

Despite the elevation of morning serum cortisol in the second and third trimesters of pregnancy, the morning salivary values as well as late-night salivary cortisol throughout all trimesters were not significantly different from control values (P > 0·5). In the postpartum period, the morning and late-night salivary cortisol values were significantly lower than in late pregnancy. The morning and late-night salivary cortisol values in women on contraceptives were also not different from those in the healthy women group.

CONCLUSION

The results of our study suggest that reference values for salivary cortisol established for a healthy adult population can be used for pregnant women and women on oral contraceptives in the initial diagnostic testing for Cushing's syndrome and adrenal insufficiency.

Chronic and acute effects of stress on energy balance: are there appropriate animal models?

Stress activates multiple neural and endocrine systems to allow an animal to respond to and survive in a threatening environment. The corticotropin-releasing factor system is a primary initiator of this integrated response, which includes activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis. The energetic response to acute stress is determined by the nature and severity of the stressor, but a typical response to an acute stressor is inhibition of food intake, increased heat production, and increased activity with sustained changes in body weight, behavior, and HPA reactivity. The effect of chronic psychological stress is more variable. In humans, chronic stress may cause weight gain in restrained eaters who show increased HPA reactivity to acute stress. This phenotype is difficult to replicate in rodent models where chronic psychological stress is more likely to cause weight loss than weight gain. An exception may be hamsters subjected to repeated bouts of social defeat or foot shock, but the data are limited. Recent reports on the food intake and body composition of subordinate members of group-housed female monkeys indicate that these animals have a similar phenotype to human stress-induced eaters, but there are a limited number of investigators with access to the model. Few stress experiments focus on energy balance, but more information on the phenotype of both humans and animal models during and after exposure to acute or chronic stress may provide novel insight into mechanisms that normally control body weight.

Salivary cortisol is a useful tool to assess the early response to pasireotide in patients with Cushing's disease

PURPOSE

Late night salivary cortisol (LNSC) is useful for diagnosing hypercortisolism and monitoring patients with Cushing's disease (CD) following pituitary surgery. It may also be a better index of cortisol secretion than serum cortisol or urinary free cortisol (UFC). No data regarding the role of LNSC in the early monitoring of patients with CD receiving drug therapy has been published. We investigated the value of LNSC in monitoring the short-term efficacy of pasireotide.

METHODS

Seven patients who were enrolled in a phase II study investigating the efficacy of pasireotide in CD (CSOM230B2208) were included in this analysis. Patients self-administered subcutaneous pasireotide 600 μg bid for 15 days. LNSC and UFC levels were assessed at baseline and day 15.

RESULTS

At baseline, all patients had elevated LNSC which was correlated significantly with UFC levels (r = 0.97, P = .0002). At day 15, LNSC was reduced in six patients. LNSC decreases were observed from day 1 (-20%) and persisted until day 15 (overall mean reduction from baseline -51%), with the greatest decrease on day 5 (-58%). At day 15, UFC levels were decreased in all patients and normalized in one that restored also salivary cortisol rhythm.

CONCLUSIONS

In patients with CD, pasireotide rapidly reduced and normalized both UFC and LNSC levels. LNSC may be a simple, non-invasive biomarker to assess the early response to pasireotide, particularly in determining whether cortisol rhythm is normalized in patients with normalized UFC levels. Further studies are warranted.

Differentiating between Cushing's disease and pseudo-Cushing's syndrome: comparison of four tests

OBJECTIVE

To evaluate the diagnostic performance of four different tests in order to differentiate between Cushing's disease (CD) and pseudo-Cushing's syndrome (PCS).

METHODS

In this prospective study, a total of 73 patients with clinical features of hypercortisolism and insufficient suppression of serum cortisol after 1 mg overnight dexamethasone and/or an elevated excretion of cortisol in 24-h urine samples were included. The circadian rhythm of serum cortisol levels as well as midnight serum cortisol (MserC) levels were assessed in all 73 patients. Late-night salivary cortisol (LNSC) concentrations were obtained in 44 patients. The dexamethasone-CRH (Dex-CRH) test was performed in 54 patients.

RESULTS

FIFTY-THREE PATIENTS WERE DIAGNOSED WITH CD AND SUBSEQUENTLY TREATED. TWENTY PATIENTS WERE CLASSIFIED AS HAVING PSC. SERUM CORTISOL CIRCADIAN RHYTHM: the diurnal rhythmicity of cortisol secretion was retained in PCS. A cortisol midnight:morning ratio of >0.67 is highly suggestive of CD (positive predictive value (PPV) 100% and negative predictive value (NPV) 73%). MserC concentration >243 nmol/l has a PPV of 98% in predicting true CD (NPV 95%). LNSC level >9.3 nmol/l predicted CD in 94% of patients (NPV 100%). Dex-CRH test: after 2 days of dexamethasone suppression, a CRH-stimulated cortisol level >87 nmol/l (T=15 min) resulted in a PPV of 100% and an NPV of 90%.

CONCLUSION

The Dex-CRH test as well as a single measurement of cortisol in serum or saliva at late (mid-) night demonstrated high diagnostic accuracy in differentiating PCS from true CD.

An approach to the evaluation and treatment of Cushing’s disease

Cushing's syndrome is an uncommon disorder involving dysregulation of the hypothalamic-pituitary-adrenal axis resulting in endogenous hypercortisolemia. It has multiple causes, but most commonly is due to hypersecretion of corticotropin from the pituitary gland, called Cushing's disease. The diagnosis of Cushing's syndrome remains a challenge to clinicians because routine hormonal assays can have significant overlap in pathological and normal states. We will review an approach to evaluating patients with suspected cortisol excess. We will also discuss treatment options and post-surgical assessment for those diagnosed with Cushing's disease.

Determination of cortisol in serum, saliva and urine

Cortisol is quantitatively the major glucocorticoid product of the adrenal cortex. The main reason to measure cortisol is to diagnose human diseases characterised by deficiency of adrenal steroid excretion in Addison's disease or overproduction in Cushing's syndrome (CS). In both cases a sensitive, accurate and reproducible assay of cortisol is required. Several methods have been described for the quantitative measurement of cortisol in both serum and urine. The most widely used methods in routine clinical laboratories are immunoassays (IA) and enzyme immunoassays (EIA), luminescence and fluorescence assays, which are available in numerous commercial kits and on automated platforms. However, there remains a number of problems in the so-called direct immunoassays if extraction and prepurification are not carried out before the assay. Recently, more specific chromatographic methods have been introduced, such as high pressure liquid chromatographic (HPLC) or liquid chromatography tandem mass spectrometric assays (LC-MS/MS). The high specificity especially of LC-MS/MS facilitates reliable measurement of cortisol both in plasma, urine and saliva samples.

Significantly high level of late-night free cortisol to creatinine ratio in urine specimen in patients with subclinical Cushing's syndrome

OBJECTIVE

Absence of a late-night cortisol nadir is a consistent biochemical abnormality in patients with cortisol-producing adenoma. We evaluated the abnormality of late-night urinary free cortisol to creatinine ratio (late-night UFCCR) in patients with subclinical Cushing's syndrome (SCS).

METHODS

Fifty-eight patients with incidentally detected adrenocortical adenomas [SCS: 9; nonfunctioning adenoma (NF): 49] were enrolled as subjects. Values measured in all patients were urinary free cortisol accumulated between 9:00 p.m. and 11:00 p.m. (late-night UFCCR), serum cortisol at 11:00 p.m. (midnight serum cortisol: MSC), serum cortisol after 1-mg overnight dexamethasone suppression test (1 mg-DST) and 24-h urinary free cortisol (UFC).

RESULTS

Median late-night UFCCR value in SCS was significantly higher than that in NF (P < 0·001). Significant correlations were observed between late-night UFCCR and each of serum cortisol after 1 mg-DST and MSC (r = 0·537, P < 0·001 and r = 0·556, P < 0·001, respectively). There was no significant correlation between serum cortisol after 1 mg-DST and 24-h UFC (r = 0·211, P = 0·112). In receiver operating characteristic analysis for diagnosis of SCS, the areas under the curves of late-night UFCCR and 24-h UFC were 0·937 (95% confidence interval 0·865-1·008) and 0·726 (0·874-0·999), respectively. Late-night UFCCR cut-off value of 4·9 nmol/μmol Cre showed a sensitivity of 100% and a specificity of 76·6%.

CONCLUSION

Patients with SCS showed higher late-night UFCCR values than those with NF. Late-night UFCCR was significantly correlated with autonomous cortisol production findings. Diagnostic performance of late-night UFCCR was superior to 24-h UFC. These results suggest that late-night UFCCR might represent one of the simple and reliable tests for SCS diagnosis.

Reassessing the reliability of the salivary cortisol assay for the diagnosis of Cushing syndrome

Objective

The cortisol concentration in saliva is 10-fold lower than total serum cortisol and accurately reflects the serum concentration, both levels being lowest around midnight. The salivary cortisol assay measures free cortisol and is unaffected by confounding factors. This study analysed published data on the sensitivity and specificity of salivary cortisol levels in the diagnosis of Cushing syndrome.

Methods

Data from studies on the use of different salivary cortisol assay techniques in the diagnosis of Cushing syndrome, published between 1998 and 2012 and retrieved using Ovid MEDLINE®, were analysed for variance and correlation.

Results

For the 11 studies analysed, mean sensitivity and specificity of the salivary cortisol assay were both >90%. Repeated measurements were easily made with this assay, enabling improved diagnostic accuracy in comparison with total serum cortisol measurements.

Conclusions

This analysis confirms the reliability of the saliva cortisol assay as pragmatic tool for the accurate diagnosis of Cushing syndrome. With many countries reporting a rising prevalence of metabolic syndrome, diabetes and obesity – in which there is often a high circulating cortisol level – salivary cortisol measurement will help distinguish these states from Cushing syndrome.

Concordance of the late night salivary cortisol in patients with Cushing's syndrome and elevated urine-free cortisol

The concordance of the late night salivary cortisol (LNSC) results with the 24-h urine-free cortisol (UFC) results in the biochemical screening for Cushing's syndrome is unknown. We investigated this in a population of Cushing's syndrome subjects. We used meta-analytic methods to pool proportions of LNSC-positive subjects from diagnostic evaluations of Cushing's syndrome subjects where both tests were performed and the UFC was elevated (any level). Cushing's syndrome was confirmed in all subjects by two out of three conventional tests. LNSC was collected between 22:00 to 24:00 h and measured around the same time period as the UFC. Minimum cutoffs of ≥4 and ≥10 nmol/L were used to determine concordance with the UFC and studies were limited to those that used radioimmunoassays or electrochemiluminiscence immunoassays for LNSC. The concordance of LNSC ≥4 nmol/L was 97 % (95 % CI 95-99 %) and studies were homogeneous. With LNSC ≥10 nmol/L, there was heterogeneity and two groups were discernible with a pooled concordance of 69 % (95 % CI 60-77 %) and 95 % (95 % CI 92-97 %). Within these sub-groups, studies were homogeneous and there was no difference between them in collection methods, assays used, geographic location, year of publication, or the quality of the underlying studies. The LNSC at a very specific cutoff detects at best 95 % of cases and at worst 69 % of cases of Cushing's syndrome that are UFC positive. The two tests become equivalent at the more sensitive cutoff (>4 nmol/L). We conclude that, given its many benefits and the currently documented equivalence to the UFC, the LNSC should replace the conventional 24-h UFC as the frontline test when screening for Cushing's syndrome.

Usefulness of salivary cortisol in the diagnosis of hypercortisolism: comparison with serum and urinary cortisol

OBJECTIVE

Several tests have been proposed to diagnose patients with Cushing's syndrome (CS). The aims of the study were: i) to evaluate the performance of salivary cortisol (SC) in hypercortisolism and ii) to compare SC with serum cortisol (SeC) and urinary cortisol.

DESIGN AND PATIENTS

This was a diagnostic study. Twenty-seven patients with untreated Cushing's disease (CD untr), 21 women consuming oral contraceptive pill (OCP), 18 pregnant women, and 89 healthy subjects (controls) were enrolled.

METHODS

SC and SeC at baseline and after the low-dose dexamethasone suppression test (LDDST) and urinary free cortisol (UFC) were measured.

RESULTS

Midnight SC had a sensitivity of 100% in the CD untr group and a specificity of 97.7% in the controls. Specificity remained high (95.2%) in women taking OCP, while in pregnant women, it decreased to 83.3%. SC after the LDDST showed a sensitivity of 96.3% in the CD untr group; specificity was 97.7% in the controls and 90.5% in OCP women. Midnight SeC had a sensitivity of 100% in the CD untr group. SeC after the LDDST had a sensitivity of 100% in the CD untr group while specificity was 97.7% in the controls and 61.9% in women taking OCP. For UFC, sensitivity was 92.6% in the CD untr group while specificity was 97.7% in the controls and 100% in the OCP group.

CONCLUSIONS

SC is a reliable parameter for the diagnosis of severe hypercortisolism, with high sensitivity and specificity. In women during pregnancy or taking OCP, the measurement of SC, identifying the free fraction, could be helpful to exclude CS.

Measurement of salivary cortisol in 2012 - laboratory techniques and clinical indications

The utility of measuring salivary cortisol has become increasingly appreciated since the early 1980s. Salivary cortisol is a measure of active free cortisol and follows the diurnal rhythm of serum or plasma cortisol. The saliva sample may be collected by drooling or through the use of absorbent swabs which are placed into the mouth until saturated. Salivary cortisol is therefore convenient for patients and research participants to collect noninvasively on an outpatient basis. Several assay techniques have been used to measure salivary cortisol, including radioimmunoassay and more recently liquid chromatography-tandem mass spectrometry. The analytical sensitivity varies between these assay methods, as does the potential for cross-reactivity with other steroids. The interpretation of salivary cortisol levels relies on rigorous standardization of sampling equipment, sampling protocols and assay technology with establishment of a local reference range. Clinically, the commonest use for salivary cortisol is measuring late-night salivary cortisol as a screening test for Cushing's syndrome. Several studies have shown diagnostic sensitivities and specificities of over 90%, which compares very favourably with other screening tests for Cushing's syndrome such as the 24-h urinary-free cortisol and the 1-mg overnight dexamethasone suppression test. There are emerging roles for the use of salivary cortisol in diagnosing adrenal insufficiency, particularly in conditions associated with low cortisol-binding globulin levels, and in the monitoring of glucocorticoid replacement. Finally, salivary cortisol has been used extensively as a biomarker of stress in a research setting, especially in studies examining psychological stress with repeated measurements.

Efficiency and tolerance of mitotane in Cushing's disease in 76 patients from a single center

CONTEXT

Alternatives to transsphenoidal pituitary surgery may be required in Cushing's disease (CD) as a first- or second-line treatment. Mitotane is a potent anti-cortisolic drug but has been rarely investigated in the treatment of CD.

OBJECTIVE

Evaluation of the efficacy and tolerance of mitotane in CD patients.

DESIGN AND SETTING

Retrospective analysis of 76 patients treated with mitotane from 219 patients diagnosed with CD between 1993 and 2009 in a single center.

MAIN OUTCOME MEASURE

Remission was defined as normalization of 24-h urinary free cortisol (24-h-UFC).

RESULTS

Remission was achieved in 48 (72%) of the 67 long-term treated patients, after a median time of 6.7 (5.2-8.2) months. Mean plasma mitotane concentration at the time of remission was 10.5 ± 8.9 mg/l, with a mean daily dose of 2.6 ± 1.1 g. A negative linear relationship was observed between plasma mitotane concentration and 24-h-UFC (P<0.0001). Seventeen of 24 (71%) patients with durable remission subsequently experienced recurrence, after a median time of 13.2 (5.0-67.9) months. At the time of treatment discontinuation, ACTH concentration was statistically associated with a lower recurrence probability (hazard ratios 0.57 (0.32-1.00), P=0.05). Intolerance leading to treatment discontinuation occurred in 19 patients (29%). A pituitary adenoma became identifiable during mitotane treatment in 12 (25%) of the 48 patients with initial negative pituitary imaging allowing subsequent transsphenoidal surgery.

CONCLUSION

Mitotane is useful at different stages of CD. Mitotane dose adjustment based on plasma concentration monitoring and side effects could control hypercortisolism in the majority of CD patients.

Salivary concentration of progesterone and cortisol significantly differs across individuals after correcting for blood hormone values

Between-individual variation of salivary progesterone (P4) and cortisol levels does not always closely reflect blood hormone concentrations. This may be partly a function of individual differences in salivary hormone excretion. We tested whether time of day at sampling and ethnicity contributed to individual variation in salivary hormones after adjusting for blood hormone levels. Forty-three Caucasian and 15 Japanese women (18-34 years) collected four sets of matched dried blood spot (DBS) and saliva specimens across a menstrual cycle (N = 232 specimen sets). Linear fixed-effects (LFE) models were used to estimate the effects of diurnal variation and ethnicity on salivary P4 and cortisol while adjusting for DBS levels. For each hormone, women with exclusively positive or negative residuals (unexplained variance) from the LFE models were categorized as high- or low-saliva-to-DBS hormone ratio (SDR; high or low salivary secretors), respectively. We found that salivary P4 (P < 0.05) was significantly higher in early morning compared to the afternoon, after controlling for DBS levels, ethnicity, and BMI. After further adjusting for this diurnal effect, significant individual variation in salivary P4 and cortisol remained: sixteen and nine women, respectively were categorized as low or high salivary secretors for both hormones (P < 0.001), suggesting systematic individual-specific variation of salivary hormonal concentration. We conclude that when saliva is used to quantify P4 or cortisol levels, time of day at sampling should be controlled. Even with this adjustment, salivary P4 and cortisol do not closely mirror between- individual variation of serum P4 and cortisol in a substantial proportion of individuals.

Cushing's disease

Cushing’s disease, or pituitary ACTH dependent Cushing’s syndrome, is a rare disease responsible for increased morbidity and mortality. Signs and symptoms of hypercortisolism are usually non specific: obesity, signs of protein wasting, increased blood pressure, variable levels of hirsutism. Diagnosis is frequently difficult, and requires a strict algorithm. First-line treatment is based on transsphenoidal surgery, which cures 80% of ACTH-secreting microadenomas. The rate of remission is lower in macroadenomas. Other therapeutic modalities including anticortisolic drugs, radiation techniques or bilateral adrenalectomy will thus be necessary to avoid long-term risks (metabolic syndrome, osteoporosis, cardiovascular disease) of hypercortisolism. This review summarizes potential pathophysiological mechanisms, diagnostic approaches, and therapies.

Reproducibility and performance of one or two samples of salivary cortisol in the diagnosis of Cushing's syndrome using an automated immunoassay system

The purpose of this article is to evaluate the variability and reproducibility of late night salivary cortisol (LNSC) using electrochemiluminescence immunoassay (ECLIA) and compare the accuracy of one or two samples in diagnosis of Cushing's syndrome (CS). We prospectively included 64 healthy volunteers (HV), 35 patients with clinically suspected CS (S), and 26 patients with confirmed CS. Nine patients in the CS group had 24-h urinary free cortisol (UFC) less than two times the upper limit of normal (mild CS). UFC and two consecutive LNSC (LNSC1, LNSC2) were collected at home. All patients in the S group had normal UFC and low-dose dexamethasone suppression test. No differences were found between the HV and S groups in UFC, LNSC1, and LNSC2. Intra-individual variability between the two samples of LNSC was 22% in HV (1.6-91%), 32% in the S group (1.6-144%), and 51% (1.6-156%) in the CS group. Variability was higher in CS patients than those in the HV (P < 0.001) and S groups (P = 0.05). The AUC of LNSC1 was 0.945 (IC 95% 0.880-1.004); when considering the highest LNSC, the AUC was 0.980 (IC 95% 0.954-1.007) (P < 0.01). We found 23% of discordant LNSC in the S group and 11% in the CS group. Three patients with CS had only one elevated LNSC, all of them with mild CS. Our results suggest that LNSC is variable, and reproducibility is affected in both CS and S patients. We found significant improvements in the diagnostic accuracy of the LNSC measurement by obtaining two samples.