Diagnostic performance of late-night salivary cortisol measured by automated electrochemiluminescence immunoassay in obese and overweight patients referred to exclude Cushing's syndrome

Psychological Stress and Intraocular Pressure in Glaucoma: A Randomized Controlled Trial

PURPOSE

To evaluate the intraocular pressure (IOP) behavior after applying a standardized protocol to induce psychological stress in patients with primary open-angle glaucoma (POAG).

DESIGN

Randomized controlled trial.

PARTICIPANTS

A total of 39 patients with POAG were included: 18 in the stress group and 21 in the control group.

METHODS

Patients were randomized to undergo the Trier Social Stress Test (TSST) or to be included in the control group. All participants were submitted to a modified diurnal tension curve (DTC) 1-4 weeks before randomization, with 3 IOP measurements performed between 8:00 am and 2:00 pm. We evaluated the response to the TSST by measuring the levels of salivary cortisol, salivary amylase, IOP, mean arterial pressure, and heart rate before, immediately after, and 40 minutes after the TSST. The State Trait Anxiety Inventory (STAI) was applied to evaluate the levels of anxiety at the same time intervals.

MAIN OUTCOME MEASURES

Changes in IOP (mmHg), salivary cortisol and amylase, heart rate, mean arterial pressure, and STAI scores.

RESULTS

At baseline, there were no significant differences between the groups regarding age (P = 0.661), sex (P = 0.669), salivary cortisol (P = 0.104), and mean DTC IOP for the right (P = 0.439) and left (P = 0.576) eyes. We observed a significant mean IOP increase of 3.8 mmHg (right eye; P < 0.001) and 4.1 mmHg (left eye; P < 0.001) when we compared IOP measurements obtained during the DTC and immediately after TSST. Salivary cortisol (5.9 nmol/L; P = 0.004), salivary amylase (323 388 UL; P = 0.004), mean arterial pressure (10.1 mmHg; P < 0.001), and heart rate (12.9 bpm; P < 0.001) also increased significantly after the TSST. In addition, 61.1% (11 of 18) of the patients in the TSST group showed an IOP increase > 4 mmHg following the test. The STAI-state score significantly increased after the TSST compared to baseline (P < 0.001) and decreased from poststress to the recovery period (P < 0.001).

CONCLUSIONS

Patients with POAG present significant elevations of IOP, salivary cortisol and amylase, mean arterial pressure, heart rate, and STAI scores after psychological stress induced by the TSST.

FINANCIAL DISCLOSURES

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Pitfalls in the Diagnosis and Management of Hypercortisolism (Cushing Syndrome) in Humans; A Review of the Laboratory Medicine Perspective

Biochemical confirmation of a diagnosis of hypercortisolism (Cushing syndrome) is vital to direct further investigations, especially given the overlap with non-autonomous conditions, such as pseudo-Cushing, and the morbidity associated with missed diagnoses. A limited narrative review was performed focusing on the laboratory perspective of the pitfalls of making a biochemical diagnosis of hypercortisolism in those presenting with presumed Cushing syndrome. Although analytically less specific, immunoassays remain cheap, quick, and reliable in most situations. Understanding cortisol metabolism can help with patient preparation, specimen selection (e.g., consideration of urine or saliva for those with possible elevations of cortisol binding globulin concentration), and method selection (e.g., mass spectrometry if there is a high risk of abnormal metabolites). Although more specific methods may be less sensitive, this can be managed. The reduction in cost and increasing ease of use makes techniques such as urine steroid profiles and salivary cortisone of interest in future pathway development. In conclusion, the limitations of current assays, particularly if well understood, do not impede diagnosis in most cases. However, in complex or borderline cases, there are other techniques to consider to aid in the confirmation of hypercortisolism.

Assessment of Vitamin D Metabolism in Patients with Cushing's Disease in Response to 150,000 IU Cholecalciferol Treatment

In this study we aimed to assess vitamin D metabolism in patients with Cushing’s disease (CD) compared to healthy individuals in the setting of bolus cholecalciferol treatment. The study group included 30 adults with active CD and the control group included 30 apparently healthy adults with similar age, sex and BMI. All participants received a single dose (150,000 IU) of cholecalciferol aqueous solution orally. Laboratory assessments including serum vitamin D metabolites (25(OH)D₃, 25(OH)D₂, 1,25(OH)₂D₃, 3-epi-25(OH)D₃ and 24,25(OH)₂D₃), free 25(OH)D, vitamin D-binding protein (DBP) and parathyroid hormone (PTH) as well as serum and urine biochemical parameters were performed before the intake and on Days 1, 3 and 7 after the administration. All data were analyzed with non-parametric statistics. Patients with CD had similar to healthy controls 25(OH)D₃ levels (p > 0.05) and higher 25(OH)D₃/24,25(OH)₂D₃ ratios (p < 0.05) throughout the study. They also had lower baseline free 25(OH)D levels (p < 0.05) despite similar DBP levels (p > 0.05) and lower albumin levels (p < 0.05); 24-h urinary free cortisol showed significant correlation with baseline 25(OH)D₃/24,25(OH)₂D₃ ratio (r = 0.36, p < 0.05). The increase in 25(OH)D₃ after cholecalciferol intake was similar in obese and non-obese states and lacked correlation with BMI (p > 0.05) among patients with CD, as opposed to the control group. Overall, patients with CD have a consistently higher 25(OH)D₃/24,25(OH)₂D₃ ratio, which is indicative of a decrease in 24-hydroxylase activity. This altered activity of the principal vitamin D catabolism might influence the effectiveness of cholecalciferol treatment. The observed difference in baseline free 25(OH)D levels is not entirely clear and requires further study.

Distinct Late-Night Salivary Cortisol Cut-Off Values for the Diagnosis of Hypercortisolism

Due to high morbidity and mortality of untreated hypercortisolism, a prompt diagnosis is essential. Measurement of late-night salivary cortisol provides a simple and non-invasive method. However, thresholds and reference ranges differ among studies. The goal of this study was to define a threshold of late-night salivary cortisol for the diagnosis of hypercortisolism based on the used assay. Moreover, the influence of different aetiologies of hypercortisolism and individual comorbidities were investigated. Prospective analyses of 217 patients, including 36 patients with proven hypercortisolism were carried out. A sum of 149 patients with suspicion of hypercortisolism but negative endocrine testing and 32 patients with hypercortisolism in remission served as control group. Late-night salivary cortisol was measured using an automated chemiluminescence immunoassay. Cut-off values were calculated by ROC analysis. The calculated cut-off value for the diagnosis of hypercortisolism was 10.1 nmol/l (sensitivity 94%; specificity 84%). Only slightly lower thresholds were obtained in patients with suspected hypercortisolism due to weight gain/obesity (9.1 nmol/l), hypertension or adrenal tumours (both 9.8 nmol/l) or pituitary adenomas (9.5 nmol/l). The late-night salivary cortisol threshold to distinguish between Cushing's disease and Cushing's disease in remission was 9.2 nmol/l. The cut-off value for the diagnosis of ectopic ACTH-production was 109.0 nmol/l (sensitivity 50%, specificity 92%). Late-night salivary cortisol is a convenient and reliable parameter for the diagnosis of hypercortisolism. Except for ectopic ACTH-production, thresholds considering different indications for evaluation of hypercortisolism were only slightly different. Therefore, they might only be useful if late-night salivary cortisol results near the established cut-off value are present.

Clinical course and outcome of patients with ACTH-dependent Cushing's syndrome infected with novel coronavirus disease-19 (COVID-19): case presentations

OBJECTIVE

To analyze the clinical presentations of patients with endogenous Cushing's syndrome (CS) affected by Coronavirus disease-19 (COVID-19).

MATERIALS AND METHODS

Patients who were referred to our clinic with active CS from 31st March to 15th May 2020 were screened for COVID-19 using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Late-night serum cortisol (64-327 nmol/L), late-night salivary cortisol (LNSC) (0.5-9.4 nmol/L), or 24-h urinary free cortisol (24 hUFC) (100-379 nmol/24 h) were measured by electrochemiluminescence immunoassay.

RESULTS

Among 22 patients with active CS we found three cases affected by COVID-19. Nonspecific inflammation markers were within the reference range or slightly elevated in these patients. A 71-year-old woman with newly diagnosed CS (late-night serum cortisol >1750 nmol/L, LNSC 908.6 nmol/L) developed dyspnea as an only symptom and died from bilateral polysegmantal hemorrhagic pneumonia 7 days later. A 38-year-old woman with a 5-year medical history of active Cushing's disease (CD) (late-night serum cortisol 581.3 nmol/L, 24 hUFC 959.7 nmol/24-h) suffered from dyspnea, cough, fever (39.3 °C) and chest pain. Oxygen therapy, antibiotics and symptomatic treatments lead to full recovery 24 days later. A 66-year-old woman with a 4-year medical history of mild CD (late-night serum cortisol 603.4 nmol/L, LNSC 10.03 nmol/L) tested positive for COVID-19 in routine screening and remained asymptomatic.

CONCLUSIONS

The outcome of COVID-19 in patients with CS depends on the severity of hypercortisolism. Thus, severe hypercortisolism is a warning sign that CS affected by COVID-19 could require emergency care despite a lack of clinical presentations and low inflammation biomarkers.

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.

Reference ranges of late-night salivary cortisol and cortisone measured by LC-MS/MS and accuracy for the diagnosis of Cushing's syndrome

PURPOSE

International guidelines recommend salivary cortisol for the diagnosis of Cushing's syndrome. Despite mass spectrometry-based assays are considered the analytical gold-standard, there is still the need to define reference intervals and diagnostic accuracy of such methodology.

METHODS

100 healthy volunteers and 50 consecutive patients were enrolled to compare LC-MS/MS and electrochemiluminescence assay for the determination of late-night salivary cortisol and cortisone. Moreover, we aimed to determine reference intervals of salivary steroids in a population of healthy individuals and diagnostic accuracy in patients with suspected hypercortisolism and in a population including also healthy individuals.

RESULTS

Method comparison highlighted a positive bias (51.8%) of immunoassay over LC-MS/MS. Reference intervals of salivary cortisol (0.17-0.97 µg/L), cortisone (0.84-4.85 µg/L) and ratio (0.08-0.30) were obtained. The most accurate thresholds of salivary cortisol for the diagnosis of hypercortisolism were 1.15 µg/L in the population with suspected hypercortisolism (AUC 1) and 1.30 µg/L in the population including also healthy individuals (AUC 1). Cut-off values of salivary cortisone (7.23 µg/L; Se 92.9%, Sp 97.2%, AUC 0.960 and Se 92.9%, Sp 99.1%, AUC 0.985 in suspected hypercortisolism and in overall population, respectively) and cortisol-to-cortisone ratio (0.20; Se 85.7%, Sp 80.6%, AUC 0.820 and Se 85.7%, Sp 85.5%, AUC 0.855 in suspected hypercortisolism and in overall population, respectively) were accurate and similar in both populations.

CONCLUSION

LC-MS/MS is the most accurate analytical platform for measuring salivary steroids. Obtained reference intervals are coherent with previously published data and diagnostic accuracy for diagnosis of overt hypercortisolism proved highly satisfactory.

Can Psychologic Stress Elevate Intraocular Pressure in Healthy Individuals?

PURPOSE

To investigate if a stress event can influence intraocular pressure (IOP) in a group of healthy individuals.

DESIGN

Case-control study.

PARTICIPANTS

A total of 28 healthy subjects were included: 17 in the stress group and 11 in the control group.

METHODS

The Trier Social Stress Test (TSST) is a tool to evaluate cortisol response to psychologic stimulation based on the stress induced by public speaking. All participants underwent a modified diurnal tension curve (DTC) 1 week before the TSST, with 3 IOP measurements performed between 8:00 am and 2:00 pm. We evaluated the response to the TSST measuring the levels of salivary cortisol, IOP, and heart rate before, immediately after, and 40 minutes after TSST. The State Trait Anxiety Inventory (STAI) was applied to evaluate the levels of anxiety at the same time intervals.

MAIN OUTCOME MEASURES

Changes in IOP (mmHg), salivary cortisol, heart rate, and STAI scores.

RESULTS

At baseline, there were no significant differences between case and controls regarding age (52.2 ± 6.26 vs. 53.8 ± 8.4 years, P = 0.661), gender (52.94% male vs. 45.45% female, P = 0.669), and ethnicity. Salivary cortisol (6.8 nmol/l, P < 0.001) and heart rate (7.2 beats/min, P = 0.035) increased significantly after the TSST. We observed a mean IOP increase of 1.0 mmHg (right eye, P = 0.003) and 1.1 mmHg (left eye, P = 0.004) when comparing IOP measurements obtained during the DTC and immediately after TSST. In addition, 35% (6/17) of the subjects in the TSST group showed an IOP increase higher than 2 mmHg after the test compared with 18% (2/11) in the control group. The STAI state score significantly increased after the stress event compared with baseline (P = 0.026) and decreased from poststress to the recovery period (P = 0.006) in the TSST group. The control group did not show significant changes in IOP, heart rate, salivary cortisol levels, and STAI scores.

CONCLUSIONS

Significant elevations of IOP, salivary cortisol, STAI scores, and heart rate occurred after inducing psychologic stress with TSST in a group of healthy individuals.

Assessment of exercise-induced stress by automated measurement of salivary cortisol concentrations within the circadian rhythm in Japanese female long-distance runners

Background

Overtraining syndrome, caused by prolonged excessive stress, results in reduced performance and cortisol responsiveness in athletes. It is necessary to collect saliva samples sequentially within circadian rhythm for assessing exercise stress by measuring cortisol concentrations, and automated cortisol measurements using electrochemiluminescence immunoassay (ECLIA) may be useful for measuring a large number of saliva samples. In this study, we evaluated the appropriate use of cortisol-based exercise stress assessment within the circadian rhythm, which may diagnose and prevent overtraining syndrome in athletes.

Methods

We collected saliva and sera from 54 healthy participants and analyzed the correlation between salivary cortisol concentrations measured by ECLIA and enzyme-linked immunosorbent assay (ELISA) or serum cortisol analysis. We also collected saliva continuously from 12 female long-distance runners on 2 consecutive days involving different intensities and types of exercise early in the morning and in the afternoon and measured salivary cortisol concentrations using ECLIA. Each exercise intensity of runners was measured by running velocities, Borg Scale score, and rate of change in the pulse rate by exercise.

Results

ECLIA-based salivary cortisol concentrations correlated positively with those detected by ELISA (ρ = 0.924, p < 0.001) and serum cortisol (ρ = 0.591, p = 0.001). In long-distance runners, circadian rhythm of salivary cortisol, including the peak after waking and the decrease promptly thereafter, were detected on both days by continuous saliva sampling. The rates of change in salivary cortisol concentrations were significantly lower after an early morning exercise than after an afternoon exercise on both days (day 1, p = 0.002, and day 2, p = 0.003). In the early morning exercise, the rate of change in salivary cortisol concentration was significantly higher on day 1 than on day 2 (p = 0.034), similar to a significant difference in running velocities (p = 0.001).

Conclusions

Our results suggest that automated ECLIA-based salivary cortisol measurements are able to detect the athletes’ circadian rhythm and compare the exercise stress intensities at the same times on different days, even in the early morning, possibly leading to the prevention of overtraining syndrome.

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.

Patients with morbid obesity should not be routinely screened for Cushing's syndrome: Results of retrospective study of patients attending a specialist weight management service

Cushing's syndrome (CS) is a rare condition which results in multi-system involvement and can lead to significant morbidity and mortality. Screening for CS in patients with obesity has been suggested to identify undiagnosed or occult cases. This study was performed to determine whether CS screening is indicated in a tier 3 weight management centre in the UK. A retrospective review of all patients referred to the weight management service between 2013 and 2016 inclusive was undertaken. A final cohort of 569 patients was obtained. Clinic letters and laboratory databases were used to obtain demographic information, patient characteristics and biochemical results. A total of 387 patients were screened using the 1 mg overnight dexamethasone suppression test (ODST) and 182 patients were screened with two 24-hour urinary free cortisol (UFC) collections. A total of 27 patients had an initial abnormal result, of which 16 underwent further testing and had normal results. Six were reviewed and did not demonstrate any clinical features of CS. Five did not attend their clinic appointments but there were neither concerning features within their referrals, nor subsequent diagnoses of CS made. No patients from this cohort were diagnosed with CS. This study does not support routine CS screening of patients affected by severe obesity referred to a specialist tier 3 weight management service. Clinical assessment should be undertaken first and further investigations performed only if deemed necessary.

Circulating Plasma microRNA to Differentiate Cushing's Disease From Ectopic ACTH Syndrome

Corticotropinomas and adrenocorticotropic hormone (ACTH)-secreting neuroendocrine tumors exhibit differential levels of some microRNAs (miRs) compared to normal tissue. Because miRs can be released from tissues into circulation, they offer promise as novel disease biomarkers. Objective: To evaluate whether miRs are differentially detected in plasma samples of patients with ACTH-dependent Cushing's syndrome (CS). Design: Case-control study. Methods: Morning fasting plasma samples were collected from 41 consecutive patients with confirmed ACTH-dependent CS and 11 healthy subjects and stored at -80°C. Twenty-one miRs previously reported to be differentially expressed in ACTH-secreting tumors vs. healthy tissue samples were quantified in plasma by qPCR. Results: Among enrolled subjects, 28 were confirmed to have Cushing's disease (CD), 13 had ectopic ACTH secretion (EAS) and 11 were healthy controls. We found statistically significant differences in the circulating levels of miR-16-5p [45.04 (95% CI 28.77-61.31) in CD vs. 5.26 (2.65-7.87) in EAS, P < 0.001; q = 0.001], miR-145-5p [0.097 (0.027-0.167) in CD vs. undetectable levels in EAS, P = 0.008; q = 0.087] and differences in miR-7g-5p [1.842 (1.283-2.400) in CD vs. 0.847 (0.187-1.507) in EAS, P = 0.02; q = 0.14]. The area under the receiver-operator (ROC) curve was 0.879 (95% CI 0.770-0.987), p < 0.001, when using miR-16-5p to distinguish between CD and EAS. Circulating levels of miR-16-5p in the healthy control group differed from that of both the CD and EAS groups. Conclusions: Plasma miR levels differ in patients with CD and EAS. In particular, miR-16-5p, miR-145-5p and miR-7g-5p are promising biomarkers for further research to differentiate ACTH-dependent CS.

Midnight salivary cortisol secretion associated with high systolic blood pressure in type 1 diabetes

OBJECTIVE

To explore associations between high midnight salivary cortisol (MSC) secretion and high blood pressure (BP) in type 1 diabetes (T1D).

METHODS

Cross-sectional study of 196 adult patients with T1D (54% men). Associations between high MSC (≥9.3 nmol/L) and high systolic BP (>130 mmHg), and high diastolic BP (>80 mmHg) were explored for all patients, users and non-users of antihypertensive drugs (AHD). Adjustments were performed for age, sex, diabetes-related variables, p-creatinine, smoking, physical inactivity, depression and medication.

RESULTS

The prevalence of high MSC differed between patients with high and low systolic BP in all 196 patients: 39 vs 13% (P = 0.001); in 60 users of AHD: 37 vs 12% (P = 0.039), and in 136 non-users of AHD: 43 vs 13% (P = 0.012). Significant associations with high systolic BP were for all patients: physical inactivity (adjusted odds ratio (AOR) 6.5), high MSC (AOR 3.9), abdominal obesity (AOR 3.7), AHD (AOR 2.9), age (per year) (AOR 1.07), and p-creatinine (per µmol/L) (AOR 1.03); for 60 users of AHD: high MSC (AOR 4.1) and age (per year) (AOR 1.11); for 136 non-users of AHD: abdominal obesity (AOR 27.4), physical inactivity (AOR 14.7), male sex (AOR 9.0), smoking (AOR 7.9), and age (per year) (AOR 1.08). High MSC was not associated with high DBP.

CONCLUSIONS

In adult patients with T1D, high systolic BP was associated with physical inactivity, high MSC secretion, abdominal obesity, p-creatinine, age, and AHD, the latter indicating treatment failure.

The diagnostic accuracy of increased late night salivary cortisol for Cushing's syndrome: a real-life prospective study

INTRODUCTION AND AIM

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).

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Development of competitive lateral flow immunoassay coupled with silver enhancement for simple and sensitive salivary cortisol detection

Cortisol is known as a stress biomarker. The measurement of cortisol levels is an early warning indicator for health conditions and diagnosis of stress-related diseases. Herein, a lateral flow immunoassay using a gold nanoparticle label with a silver enhancement system was developed for the simple, sensitive and rapid detection of cortisol. The developed assay was based on a competitive platform of which cortisol-BSA conjugate was immobilized at the test zone to compete with an analyte. The quantitative analysis was performed using gold nanoparticles (AuNPs) as signal labeling. Sequentially, the silver enhancement solution was applied in order to enhance the sensitivity of the assay with the results easily seen by the naked eye. Using this system, the limit of detection (LOD) was found to be 0.5 ng/mL with a 3.6 fold more sensitive detection than without the enhancement system (LOD = 1.8 ng/mL). The salivary cortisol analysis was in the range of 0.5-150 ng/mL (R² = 0.9984), which is in the clinical acceptable range. For the semi-quantitative analysis, the intensity color of the results was analyzed using an image processing program. The proposed method was successfully applied to detect cortisol in saliva. In addition, the results from our method also complied with the ones of those obtained by using the commercial enzyme-linked immunosorbent assay (ELISA). This developed assay offers great promise for a non-invasive screening test of salivary cortisol.

Specificity of late-night salivary cortisol measured by automated electrochemiluminescence immunoassay for Cushing's disease in an obese population

PURPOSE

Data about the specificity of late-night salivary cortisol (LNSC) in obese subjects are still conflicting. Therefore, with this study, we aimed to evaluate the specificity of LNSC measurement in an obese cohort with or without type 2 diabetes mellitus (T2DM) using an automated electrochemiluminescence immunoassay (ECLIA).

METHODS

A total number of 157 patients involving 40 healthy subjects (HS) with BMI < 25 kg/m², 83 obese subjects (OS) with BMI ≥ 35 kg/m², and 34 histopathologically proven Cushing's disease (CD) were included. All patients underwent LNSC testing. Salivary cortisol was measured at 11 p.m. for all groups using an ECLIA. Reference range was established using values of LNSCs of HS and ROC curves were used to determine diagnostic cutoffs.

RESULTS

In the HS group, mean LNSC was 4.7 nmol/l (SD ± 3.1), while the OS group had a mean value of 10.9 nmol/l (SD ± 7.5) and the CD group of 19.9 nmol/l (SD ± 15.4). All groups differed significantly (p < 0.001). The ROC analysis of CD against HS alone showed a sensitivity of 85.3% and a specificity of 87.5% with a cut-off value of 8.3 nmol/l. The ROC analysis between OS and CD showed a maximum sensitivity of 67.6% and specificity of 78.3% for a cut-off value of 12.3 nmol/l. Taken both (HS and OS) groups together against the CD group, ROC analysis showed a maximum sensitivity of 67.6% and specificity of 85.4% for a cut-off value of 12.3 nmol/l. No correlation was found between BMI, T2DM, and LNSC for all groups.

CONCLUSIONS

In our obese cohort, we found that LNSC assayed by ECLIA had a low specificity in the diagnosis of CD.

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.

Effects of endogenous hypercortisolism on bone mRNA and microRNA expression in humans

Hypercortisolism in humans suppresses osteoblastogenesis and osteoblast function through the upregulation of Wnt-signaling antagonists (sclerostin, Dkk1) and changes in microRNAs levels (miR-125b-5p, miR-218-5p, miR-34a-5p, miR-188-3p, miR-199a-5p) which are associated with mesenchymal stem-cell commitment to adipocytes or cartilage cells over the osteoblasts.

INTRODUCTION

The purpose of this study was to evaluate the responses of bone to chronic glucocorticoid (GC) excess by measuring the levels of selected mRNA and microRNA (miR) in bone samples of patients with Cushing's disease (CD).

METHODS

Bone samples were obtained during transsphenoidal adenomectomy from the sphenoid bone (sella turcica) from 16 patients with clinically and biochemically evident CD and 10 patients with clinically non-functioning pituitary adenomas (NFPA) matched by sex, age, and body mass index. Quantitative polymerase chain reactions (qPCR) were used to examine the expression of genes (mRNA and miRs) known to be involved in bone remodeling regulation based on studies in animals and cell culture.

RESULTS

Hypercortisolism was associated with the downregulation of genes involved in osteoblast function and maturation (ACP5, ALPL, BGLAP, COL1A1, COL1A2, BMP2, RUNX2, TWIST1). An excess of GC caused increased expression of Wnt-signaling antagonists (Dkk1, SOST) and changes in the levels of miRs that are known to suppress osteoblastogenesis (miR-125b-5p, miR-218-5p, miR-34a-5p, miR-188-3p, miR-199a-5p) p < 0.05, q < 0.1. Interestingly, compensatory mechanisms were found in long-term hypercortisolism: upregulation of Wnt10b, LRP5, and LRP6; downregulation of SFRP4; changes in miRs involved in osteoblastogenesis (miR-210-5p, miR-135a-5p, miR-211, miR-23a-3p, miR-204-5p); and downregulation of genes associated with osteoclastogenesis. None of these changes prevented the suppression of bone formation.

CONCLUSIONS

An excess of endogenous GC in humans suppresses bone formation through the upregulation of Wnt-signaling antagonists and dysregulation of miRs involved in mesenchymal stem-cell commitment. Both Wnt-signaling antagonists and miRs seem to be promising targets for further research in therapeutic intervention in glucocorticoid-induced osteoporosis.

Diagnostic performance of osteocalcin measurements in patients with endogenous Cushing's syndrome

The aim of this study was to evaluate the diagnostic performance of osteocalcin (OC), as measured by automated electrochemiluminescence immunoassay (ECLIA), in identifying Cushing's syndrome (CS) in two separate populations: among obese and overweight subjects and among women of postmenopausal age with osteoporosis. Among the 106 referral patients with obesity, CS was confirmed in 42 cases. The patients of the referred population provided late-night salivary cortisol (LNSC), underwent low-dose dexamethasone suppression testing (DST) and were further evaluated until CS was pathologically confirmed. A threshold of OC-8.3 ng ml(-1) differentiated CS among obese and overweight subjects with a sensitivity of 73.8% (95% confidence interval (CI) 58.9-84.7) and a specificity of 96.9% (95% CI 89.3-99.1). The total area under the receiver operating characteristic curve (AUC) was 0.859 (95% CI 0.773-0.945), which was lower than LNSC or DST (P=0.01). In the retrospective portion of the study, the OC levels were evaluated in 67 subjects with newly diagnosed postmenopausal osteoporosis and in 23 patients (older than 45) with newly diagnosed CS and osteoporosis (presence of low traumatic fractures or T-score P-2.5). The diagnostic performance of OC for osteoporosis due to CS was within an AUC of 0.959 (95% CI 0.887-1.00). A threshold for OC of 8.3 ng ml-1 yielded a sensitivity of 95.4% (95% CI 78.2-99.2%) and a specificity of 98.5% (95% CI 92.0-99.7%). Thus, osteocalcin could be used in the diagnostic testing for endogenous hypercortisolism in patients referred to exclude CS and to identify CS among patients of postmenopausal age with osteoporosis.

Recommendations of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism for the diagnosis of Cushing's disease in Brazil

Although it is a rare condition, the accurate diagnosis and treatment of Cushing's disease is important due to its higher morbidity and mortality compared to the general population, which is attributed to cardiovascular diseases, diabetes mellitus and infections. Screening for hypercortisolism is recommended for patients who present multiple and progressive clinical signs and symptoms, especially those who are considered to be more specific to Cushing's syndrome, abnormal findings relative to age (e.g., spinal osteoporosis and high blood pressure in young patients), weight gain associated with reduced growth rate in the pediatric population and for those with adrenal incidentalomas. Routine screening is not recommended for other groups of patients, such as those with obesity or diabetes mellitus. Magnetic resonance imaging (MRI) of the pituitary, the corticotropin-releasing hormone (CRH) test and the high-dose dexamethasone suppression test are the main tests for the differential diagnosis of ACTH-dependent Cushing's syndrome. Bilateral and simultaneous petrosal sinus sampling is the gold standard method and is performed when the triad of initial tests is inconclusive, doubtful or conflicting. The aim of this article is to provide information on the early detection and establishment of a proper diagnosis of Cushing's disease, recommending follow-up of these patients at experienced referral centers. Arch Endocrinol Metab. 2016;60(3):267-86.

Affect school and script analysis versus basic body awareness therapy in the treatment of psychological symptoms in patients with diabetes and high HbA1c concentrations: two study protocols for two randomized controlled trials

Background

Depression is linked with alexithymia, anxiety, high HbA1c concentrations, disturbances of cortisol secretion, increased prevalence of diabetes complications and all-cause mortality. The psycho-educational method ‘affect school with script analysis’ and the mind-body therapy ‘basic body awareness treatment’ will be trialled in patients with diabetes, high HbA1c concentrations and psychological symptoms. The primary outcome measure is change in symptoms of depression. Secondary outcome measures are changes in HbA1c concentrations, midnight salivary cortisol concentration, symptoms of alexithymia, anxiety, self-image measures, use of antidepressants, incidence of diabetes complications and mortality.

Methods

Two studies will be performed. Study I is an open-labeled parallel-group study with a two-arm randomized controlled trial design. Patients are randomized to either affect school with script analysis or to basic body awareness treatment. According to power calculations, 64 persons are required in each intervention arm at the last follow-up session. Patients with type 1 or type 2 diabetes were recruited from one hospital diabetes outpatient clinic in 2009. The trial will be completed in 2016. Study II is a multicentre open-labeled parallel-group three-arm randomized controlled trial. Patients will be randomized to affect school with script analysis, to basic body awareness treatment, or to treatment as usual. Power calculations show that 70 persons are required in each arm at the last follow-up session. Patients with type 2 diabetes will be recruited from primary care. This study will start in 2016 and finish in 2023. For both studies, the inclusion criteria are: HbA1c concentration ≥62.5 mmol/mol; depression, alexithymia, anxiety or a negative self-image; age 18–59 years; and diabetes duration ≥1 year. The exclusion criteria are pregnancy, severe comorbidities, cognitive deficiencies or inadequate Swedish. Depression, anxiety, alexithymia and self-image are assessed using self-report instruments. HbA1c concentration, midnight salivary cortisol concentration, blood pressure, serum lipid concentrations and anthropometrics are measured. Data are collected from computerized medical records and the Swedish national diabetes and causes of death registers.

Discussion

Whether the “affect school with script analysis” will reduce psychological symptoms, increase emotional awareness and improve diabetes related factors will be tried, and compared to “basic body awareness treatment” and treatment as usual.

Trial registration

ClinicalTrials.gov: NCT01714986

The risk factors for fractures and trabecular bone-score value in patients with endogenous Cushing's syndrome

In a cohort study of 182 consecutive patients with active endogenous Cushing's syndrome, the only predictor of fracture occurrence after adjustment for age, gender bone mineral density (BMD) and trabecular bone score (TBS) was 24-h urinary free cortisol (24hUFC) levels with a threshold of 1472 nmol/24 h (odds ratio, 3.00 (95% confidence interval (CI), 1.52-5.92); p = 0.002).

INTRODUCTION

The aim was to estimate the risk factors for fracture in subjects with endogenous Cushing's syndrome (CS) and to evaluate the value of the TBS in these patients.

METHODS

All enrolled patients with CS (n = 182) were interviewed in relation to low-traumatic fractures and underwent lateral X-ray imaging from T4 to L5. BMD measurements were performed using a DXA Prodigy device (GEHC Lunar, Madison, Wisconsin, USA). The TBS was derived retrospectively from existing BMD scans, blinded to clinical outcome, using TBS iNsight software v2.1 (Medimaps, Merignac, France). Urinary free cortisol (24hUFC) was measured by immunochemiluminescence assay (reference range, 60-413 nmol/24 h).

RESULTS

Among enrolled patients with CS (149 females; 33 males; mean age, 37.8 years (95% confidence interval, 34.2-39.1); 24hUFC, 2370 nmol/24 h (2087-2632), fractures were confirmed in 81 (44.5%) patients, with 70 suffering from vertebral fractures, which were multiple in 53 cases; 24 patients reported non-vertebral fractures. The mean spine TBS was 1.207 (1.187-1.228), and TBS Z-score was -1.86 (-2.07 to -1.65); area under the curve (AUC) was used to predict fracture (mean spine TBS) = 0.548 (95% CI, 0.454-0.641)). In the final regression model, the only predictor of fracture occurrence was 24hUFC levels (p = 0.001), with an increase of 1.041 (95% CI, 1.019-1.063), calculated for every 100 nmol/24-h cortisol elevation (AUC (24hUFC) = 0.705 (95% CI, 0.629-0.782)).

CONCLUSIONS

Young patients with CS have a low TBS. However, the only predictor of low traumatic fracture is the severity of the disease itself, indicated by high 24hUFC levels.

Cushing’s disease: the clinical features, diagnostics, differential diagnostics, and methods of treatment

The present guidelines on diagnostics, differential diagnostics, and methods of treatment of Cushing’s disease have been developed by a group of Russian specialists.

Cushing's syndrome in type 2 diabetes patients with poor glycemic control

Cushing's syndrome may be more frequent in some specific patient groups such as type 2 diabetes and obesity. The aim of this study was to investigate the prevalence of Cushing's syndrome in outpatients with type 2 diabetes with poor glycemic control despite at least 3-months insulin therapy. Outpatients with type 2 diabetes whose glycemic control is poor (Hb Alc value >7 %) despite receiving at least 3-months long insulin treatment (insulin alone or insulin with oral antidiabetics) were included. Patients with classic features of Cushing's syndrome were excluded. Overnight 1 mg dexamethasone suppression test (DST) was performed as a screening test. A total of 277 patients with type 2 diabetes whose glycemic control is poor (Hb Alc value >7 %) despite insulin therapy were included. Two of the 277 patients with type 2 diabetes were diagnosed with Cushing's syndrome (0.72 %). Hypertension was statistically more frequent in the patients with cortisol levels ≥1.8 μg/dL than the patients with cortisol levels <1.8 μg/dL after overnight 1 mg DST (p = 0.041). Statistically significant correlation was determined between cortisol levels after 1 mg DST and age, daily insulin dose (r = 0.266 and p < 0.001, r = 0.163 and p = 0.008, respectively). According to our findings, the prevalence of Cushing's syndrome among patients with type 2 diabetes with poor glycemic control despite insulin therapy is much higher than in the general population. The patients with type 2 diabetes with poor glycemic control despite at least three months of insulin therapy should be additionally tested for Cushing's syndrome if they have high dose insülin requirements.

Depression, smoking, physical inactivity and season independently associated with midnight salivary cortisol in type 1 diabetes

BACKGROUND

Disturbances of the circadian rhythm of cortisol secretion are associated with depression, coronary calcification, and higher all-cause and cardiovascular mortality.The primary aim of this study was to test the associations between midnight salivary cortisol (MSC), depression and HbA1c, and control for behavioural, environmental and intra individual factors with possible impact on cortisol secretion, like smoking, physical inactivity, season, medication, diabetes duration, severe hypoglycemia episodes, age and gender in patients with type 1 diabetes. Secondary aims were to present MSC levels for a reference group of non-depressed type 1 diabetes patients with a healthy life style (physically active and non-smoking), and to explore seasonal variations.

METHODS

A cross-sectional population based study of 196 patients (54% men and 46% women) aged 18-59 years that participated in a randomized controlled trial targeting depression in type 1 diabetes. Depression was assessed by the Hospital Anxiety and Depression Scale-depression subscale. MSC, HbA1c, serum-lipids, blood pressure, waist circumference and data from medical records and the Swedish National Diabetes Registry were collected.

RESULTS

Thirty four patients (17%) had MSC ≥9.3 nmol/L, which was associated with smoking (AOR 5.5), spring season (AOR 4.3), physical inactivity (AOR 3.9), self-reported depression (AOR 3.1), and older age (per year) (AOR 1.08). HbA1c >70 mmol/mol (>8.6%) (AOR 4.2) and MSC ≥9.3 nmol/L (AOR 4.4) were independently linked to self-reported depression. Season was strongly associated with MSC levels and no other variables studied showed seasonal variations. In a reference group of 137 non-depressed patients with a healthy life style (physically active, non-smoking) the median MSC level was 4.6 nmol/L (range 1.9-23.0).

CONCLUSIONS

In this study of patients with type 1 diabetes high MSC was linked to smoking, physical inactivity, depression, season and older age. Thus a high cortisol value identified three major targets for treatment in type 1 diabetes.

Harmful effects of functional hypercortisolism: a working hypothesis

Functional hypercortisolism (FH) is caused by conditions able to chronically activate hypothalamic-pituitary-adrenal axis and usually occurs in cases of major depression, anorexia nervosa, bulimia nervosa, alcoholism, diabetes mellitus, simple obesity, polycystic ovary syndrome, obstructive sleep apnea syndrome, panic disorder, generalized anxiety disorder, shift work, and end-stage renal disease. Most of these states belong to pseudo-Cushing disease, a condition which is difficult to distinguish from Cushing's syndrome and characterized not only by biochemical findings but also by objective ones that can be attributed to hypercortisolism (e.g., striae rubrae, central obesity, skin atrophy, easy bruising, etc.). This hormonal imbalance, although reversible and generally mild, could mediate some systemic complications, mainly but not only of a metabolic/cardiovascular nature, which are present in these states and are largely the same as those present in Cushing's syndrome. In this review we aim to discuss the evidence suggesting the emerging negative role for FH.

Pathogenesis of hepatic steatosis: The link between hypercortisolism and non-alcoholic fatty liver disease

Based on the available literature, non alcoholic fatty liver disease or generally speaking, hepatic steatosis, is more frequent among people with diabetes and obesity, and is almost universally present amongst morbidly obese diabetic patients. Non alcoholic fatty liver disease is being increasingly recognized as a common liver condition in the developed world, with non alcoholic steatohepatitis projected to be the leading cause of liver transplantation. Previous data report that only 20% of patients with Cushing’s syndrome have hepatic steatosis. Aiming at clarifying the reasons whereby patients suffering from Cushing’s syndrome - a condition characterized by profound metabolic changes - present low prevalence of hepatic steatosis, the Authors reviewed the current concepts on the link between hypercortisolism and obesity/metabolic syndrome. They hypothesize that this low prevalence of fat accumulation in the liver of patients with Cushing’s syndrome could result from the inhibition of the so-called low-grade chronic-inflammation, mainly mediated by Interleukin 6, due to an excess of cortisol, a hormone characterized by an anti-inflammatory effect. The Cushing’s syndrome, speculatively considered as an in vivo model of the hepatic steatosis, could also help clarify the mechanisms of non alcoholic fatty liver disease.

Recent advances in cortisol sensing technologies for point-of-care application

Everyday lifestyle related issues are the main cause of psychological stress, which contributes to health disparities experienced by individuals. Prolonged exposure to stress leads to the activation of signaling pathways from the brain that leads to release of cortisol from the adrenal cortex. Various biomarkers have been affected by psychological stress, but cortisol "a steroid hormone" is known as a potential biomarker for its estimation. Cortisol can also be used as a target analyte marker to determine the effect of exposure such as organophosphates on central nervous system, which alters the endocrine system, leading to imbalance in cortisol secretion. Cortisol secretion of individuals depends on day-night cycle and field environment hence its detection at point-of-care (POC) is deemed essential to provide personalized healthcare. Chromatographic techniques have been traditionally used to detect cortisol. The issues relating to assay formation, system complexity, and multistep extraction/purification limits its application in the field. In order to overcome these issues and to make portable and effective miniaturized platform, various immunoassays sensing strategies are being explored. However, electrochemical immunosensing of cortisol is considered as a recent advancement towards POC application. Highly sensitive, label-free and selective cortisol immunosensor based on microelectrodes are being integrated with the microfluidic system for automated diurnal cortisol monitoring useful for personalized healthcare. Although the reported sensing devices for cortisol detection may have a great scope to improve portability, electronic designing, performance of the integrated sensor, data safety and lifetime for point-of-care applications, This review is an attempt to describe the various cortisol sensing platforms and their potential to be integrated into a wearable system for online and continuous monitoring of cortisol rhythm at POC as a function of one's environment.

Update on late-night salivary cortisol for the diagnosis of Cushing's syndrome: methodological considerations

Late-night salivary cortisol (LNSC) is now considered the best approach to screen patients suspected of having endogenous hypercortisolism (Cushing's syndrome). As the use of LNSC increases, new preanalytic and analytic issues have arisen. The routine immunoassay for salivary cortisol seems to have better diagnostic performance than liquid chromatograph/tandem mass spectrometry, although measurement of normal salivary cortisone concentrations with the latter technique is very useful in identifying samples contaminated with topical hydrocortisone. LNSC is very useful in screening for Cushing's syndrome in women with increased corticosteroid-binding globulin resulting from estrogen therapy or pregnancy. Two LNSCs from each patient is recommended for routine screening, although one adequate saliva sample seems to perform well. The overnight dexamethasone suppression test remains superior to LNSC in the evaluation of potential subclinical hypercortisolism in patients with adrenal incidentalomas. Periodic assessment of LNSC is extremely useful in monitoring patients for recurrence of Cushing's disease after pituitary surgery. With the large increase in the number LNSCs being ordered around the world, it is likely that more preanalytic and analytic issues will arise, which laboratorians and clinical chemists will need to resolve.

Serum extracellular secreted antagonists of the canonical Wnt/β-catenin signaling pathway in patients with Cushing's syndrome

Patients with endogenous hypercortisolism have higher sclerostin, but do not differ in Dickkopf 1 (Dkk1) or secreted frizzled-related protein 1 (SFRP1) levels as compared to healthy control.

INTRODUCTION

Endogenous Cushing's syndrome (CS), usually affecting young and otherwise healthy patients, is a good model to validate the effects of supraphysiological levels of glucocorticoids in humans. This study evaluates circulating levels of extracellular antagonists of the Wnt/β-catenin signaling pathway (sclerostin, Dkk1, SFRP1) in patients with CS versus healthy individuals.

METHODS

Forty patients with clinically and biochemically evident CS and 40 sex-, age-, and body mass index-matched healthy subjects provided fasting serum samples for sclerostin, SFRP1 and Dkk1, along with bone turnover markers.

RESULTS

Patients with CS had higher sclerostin levels (34.5 (30.3-37.1) pmol/L) versus healthy individuals (29.9 (24.3-36.8) pmol/L) (p = 0.032). Differences in sclerostin were due to the lack of lower sclerostin values rather than an increase in protein levels above the upper limits of the healthy control. The odds of sclerostin levels being higher than 30 pmol/L were greater in patients with CS as compared with the odds in healthy subjects (odds ratio = 3.81 95 % confidence interval 1.45-10.02) (p = 0.01). It coexisted with suppressed bone formation and unchanged bone resorption markers. Dkk1, SFRP1 did not differ from the control group.

CONCLUSIONS

Of all the tested proteins (sclerostin, Dkk1, SFRP1), only sclerostin showed a significant difference when contrasting CS with healthy subjects. Hypercortisolism might prevent the down-regulation of sclerostin. Targeting sclerostin seems to be a promising therapeutic approach to treating osteoporosis in patients with CS.

Double pituitary adenomas

Double pituitary adenomas represent up to 2.6 % of pituitary adenomas in large surgical series and up to 3.3 % of patients with Cushing's disease have been found to have double or multiple pituitary adenomas. We report the case of a 60-year-old male patient whose medical history began in 2002 with erectile dysfunction; hyperprolactinemia was found and MRI showed a 6-mm area of delayed enhancement in the lateral portion of the right pituitary lobe. Treatment with cabergoline was started with normalization of prolactin levels; the following MRI, performed in 2005 and 2008, showed shrinkage of the pituitary lesion. In 2005, the patient began to manifest weight gain, hypertension, and facial plethora, but no further evaluations were done. In January 2010, the patient came to our attention and underwent multiple tests that suggested Cushing's disease. A new MRI was negative. Bilateral inferior petrosal sinus sampling showed significant pituitary-to-peripheral ratio and, in May 2010, the patient underwent exploratory pituitary surgery with evidence of a 1-2-mm white-coloured midline area compatible with pituitary adenoma that was surgically removed. Post-operatively, the patient's clinical conditions improved with onset of secondary hypoadrenalism. The histologic examination confirmed a pituitary adenoma (immunostaining was found to be positive for ACTH and negative for prolactin). We report the case of an ACTH-producing microadenoma metachronous to a prolactin secreting microadenoma although not confirmed histologically, shrunk by medical treatment. A review of data in the literature regarding double or multiple pituitary adenomas has also been done.

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.

Circadian rhythm of salivary cortisol in infants with congenital heart disease

Children with congenital heart disease (CHD) have associated extracardiac co-morbidities at the time of surgery and during ongoing growth and development. Perioperative events include disrupted glucose homeostasis, capillary leak, and fluid retention. The hypothalamic-pituitary-adrenal (HPA) axis has an important role in homeostasis in that the secretion of cortisol contributes to the response to stress, glucose regulation, blood volume control, and immune regulation. We investigated the diurnal rhythm of the HPA axis in infants with CHD by measuring salivary cortisol in the morning (0600-0900 h-circadian peak) and evening (2100-2400 h-circadian nadir). Twenty-nine infants aged 12 weeks to 1 year were included: 16 with acyanotic disease (SpO₂ ≥ 90 %) and 13 with cyanotic disease (SpO2 < 90 %). Morning salivary cortisol was similar between the two groups [acyanotic 7.0 nmol/L (1.8-23.1); cyanotic 9.7 nmol/L (0.9-15.6); p = 0.68]. Evening salivary cortisol was similar between the two groups [acyanotic 0.9 nmol/L (0.2-8.5); cyanotic 1.4 nmol/L (0.5-14.9); p = 0.32]. Both cyanotic and acyanotic groups demonstrated an intact diurnal rhythm. In conclusion, chronic hypoxia secondary to cyanotic CHD does not affect the circadian rhythm of the HPA axis. By 12 weeks of age, infants with hypoxia secondary to cyanotic CHD have a normal cortisol diurnal rhythm.