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

Cushing Syndrome in Childhood

We describe a 15-year-old boy who presented with low back pain due to vertebral compression fractures, growth deceleration, excessive weight gain, rounded facies, dorsocervical fat pad, and hypertension. He was diagnosed as having Cushing syndrome (CS) due to primary pigmented nodular adrenocortical disease resulting in excess cortisol produced by the adrenal glands, leading to disruption of the hypothalamic-pituitary-adrenal axis. The most common cause of CS is exogenous glucocorticoids, with endogenous causes being extremely rare, often leading to delay in diagnosis or misdiagnosis. Herein, we review clinical presentation, screening for hypercortisolism, and decision-making in the diagnosis of CS, as well as therapeutic approaches. The wide range of clinical presentations in pediatric CS and the rarity of the condition can lead to difficulty in the recognition, diagnosis, and subsequent management of these patients. CS can be difficult to differentiate from more common exogenous obesity, and outpatient screening of cortisol excess is challenging. Early recognition and treatment of CS is necessary to avoid multisystemic complications, and patients with suspected endogenous CS should be referred to a tertiary care center with experienced pediatric endocrinology and surgery specialists. Further confirmatory diagnostic tests are necessary to distinguish corticotropin-independent from corticotropin-dependent forms of CS, including a high-dose dexamethasone suppression test, a corticotropin-releasing hormone stimulation test, and imaging. There can be challenges to the evaluation of CS, including complex inpatient testing and difficulty with localization on imaging. Long-term sequelae of CS, including adrenal insufficiency, obesity, hypertension, and mental health disorders, may remain despite definitive surgical treatment, meriting close follow-up with the primary care clinician and subspecialists.

Salivary cortisol and cortisone in diagnosis of Cushing's syndrome - a comparison of six different analytical methods

OBJECTIVES

Salivary cortisol and cortisone at late night and after dexamethasone suppression test (DST) are increasingly used for screening of Cushing's syndrome (CS). We aimed to establish reference intervals for salivary cortisol and cortisone with three liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques and for salivary cortisol with three immunoassays (IAs), and evaluate their diagnostic accuracy for CS.

METHODS

Salivary samples at 08:00 h, 23:00 h and 08:00 h after a 1-mg DST were collected from a reference population (n=155) and patients with CS (n=22). Sample aliquots were analyzed by three LC-MS/MS and three IA methods. After establishing reference intervals, the upper reference limit (URL) for each method was used to calculate sensitivity and specificity for CS. Diagnostic accuracy was evaluated by comparing ROC curves.

RESULTS

URLs for salivary cortisol at 23:00 h were similar for the LC-MS/MS methods (3.4-3.9 nmol/L), but varied between IAs: Roche (5.8 nmol/L), Salimetrics (4.3 nmol/L), Cisbio (21.6 nmol/L). Corresponding URLs after DST were 0.7-1.0, and 2.4, 4.0 and 5.4 nmol/L, respectively. Salivary cortisone URLs were 13.5-16.6 nmol/L at 23:00 h and 3.0-3.5 nmol/L at 08:00 h after DST. All methods had ROC AUCs ≥0.96.

CONCLUSIONS

We present robust reference intervals for salivary cortisol and cortisone at 08:00 h, 23:00 h and 08:00 h after DST for several clinically used methods. The similarities between LC-MS/MS methods allows for direct comparison of absolute values. Diagnostic accuracy for CS was high for all salivary cortisol and cortisone LC-MS/MS methods and salivary cortisol IAs evaluated.

Endogenous Cushing's syndrome during pregnancy

Endogenous Cushing's syndrome (CS) is rare during pregnancy, probably because hypercortisolism induces anovulation and infertility. To date, slightly above 200 cases have been reported in the literature. The most frequent etiology of CS diagnosed during gestation is from primary adrenal causes, namely adrenal adenomas and an entity called pregnancy-induced CS. The latter can be secondary to the aberrant adrenal expression of luteinizing hormone/human chorionic gonadotropin receptor (LHCGR) in the adrenal lesions. Diagnosis of CS during pregnancy is extremely challenging, as a consequence of the physiologic hypercortisolism normally present during pregnancy. Assessment of excess cortisol production tests should be interpreted cautiously using adapted upper limits of normal criteria for pregnant patients and a high index of suspicion is required for diagnosis. Imaging is also limited due to high risk of radiation exposure with computed tomography and teratogenicity with contrast agents. The optimal treatment strategy is surgical resection of adrenal adenoma or pituitary adenoma, ideally before 24 weeks of gestation to reduce the risk of maternal and fetal complications. In mild cases, surgery can be postponed until after delivery and treatment should focus on controlling metabolic complications of hypercortisolism, such as hypertension and dysglycemia. Maternal and fetal outcomes of excess cortisol exposure, except fetal loss, are not readily improved by successful treatment of hypercortisolism.

Salivary Steroid Collection in Children Under Conditions Replicating Home Sampling

CONTEXT

Measurement of salivary glucocorticoids is an accepted method for testing adrenal function but there are few data on stability during home collection. Current salivary collection techniques require active participation or present a choking hazard and are unsuitable for young children.

OBJECTIVE

We sought to compare different salivary collection methods; assess the stability of salivary glucocorticoids under conditions replicating home collection; and assess patient tolerability and caregiver acceptability of a salivary collection device for young children, a swab encased in an infant pacifier (SaliPac).

METHODS

Six healthy adults collected salivary samples using a Salivette Cortisol, passive drool, and SalivaBio at night, waking, and 3 Pm for five days. Time to collect 1-mL saliva using the SalivaBio and SaliPac and caregiver acceptability were assessed in 30 children younger than 6 years. Saliva was stored at 4 °C, room temperature (RT), and 50 °C for 24, 48, 72 hours and 1 week to replicate potential postage conditions. Salivary cortisol and cortisone concentrations were measured by mass spectrometry.

RESULTS

There was no difference in salivary glucocorticoid concentrations using the 3 collection methods. Salivary cortisol and cortisone were stable for 72 hours at RT and 4 °C, and repeated freeze-thaw cycles did not cause significant degradation. In children younger than 6 years the SalivaBio and SaliPac were well tolerated and collected sufficient saliva for salivary steroid analysis in less than 4 minutes.

CONCLUSION

Salivette, passive drool, and SalivaBio collect samples with comparable salivary cortisol and cortisone concentrations, which are stable under conditions replicating home collection. SaliPac is an acceptable device for salivary sampling in young children.

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.

Assessment of dim light melatonin onset based on plasma and saliva samples

Melatonin (MELA) is a nocturnal hormone involved in the regulation of the circadian rhythm. MELA can be detected in plasma and saliva, and its salivary concentration strongly correlates with its plasma concentration. Dim light melatonin onset (DLMO) is considered to be the most accurate objective marker for assessing the circadian phase. The purpose of the study was to establish a method for the determination of MELA in plasma and saliva based on the liquid chromatography with tandem mass spectrometry (LC-MS/MS) and compare DLMO using both plasma and saliva matrices. The validation of the LC-MS/MS methods was performed in accordance with the European Medicines Agency (EMA) guideline. The study was conducted on a group of 21 volunteers, male and females, aged 26-54 years. Plasma and saliva were collected at five time points: between 20:00 and 00:00 hours. The MELA concentration was determined by the LC-MS/MS. The DLMO was considered as the point in time when MELA concentration exceeds 20 pg/mL in plasma and 7 pg/mL in saliva. The correlation coefficient between the plasma and salivary MELA concentration was r = 0.764 (p < .001). The ratio of the plasma/saliva MELA concentrations was 2.87. The mean time of the DLMO in the plasma was 21:30 ± 0:45 hours, and in the saliva was as follows: 21:34 ± 1:00 hours. The correlation between the DLMO, calculated based on the plasma and saliva MELA profiles, was r = 0.679 (p < .05). The determination of salivary MELA concentration using LC-MS/MS allows for the determination of the DLMO. Our method may be applied in clinical practice for the diagnosis and monitoring of circadian rhythm disorders.Abbreviations: CE: Collision Energy; CID: Collision-Induced Dissociation; DL: Desolvation Module; DLMO: Dim Light Melatonin Onset; EFSA: European Food Safety Authority; EMA: European Medicines Agency; ESI: electrospray ionization; HB: heat block; HPLC: high performance liquid chromatography; IS: internal standard; K₃EDTA: ethylenediaminetetraacetic acid tripotassium salt; LC-MS/MS: liquid chromatography with tandem mass spectrometry; LLE: liquid-liquid extraction; LLOQ: lower limit of quantification; MELA: melatonin; MELA-D₄: melatonin-d₄; MRM: multiple reaction monitoring; Q1: quadrupole 1; Q3: quadrupole 3; RE: relative error; RIA: radioimmunoassay; RSD: relative standard deviation; SD: standard deviation; ULOQ: upper limit of quantification.

Diagnosis and treatment outcomes of Cushing's disease during pregnancy

PURPOSE

We report a case of a pregnant woman with Cushing's disease (CD) and performed a systematic review of literature on diagnosis, treatment, maternal and fetal outcomes of CD in pregnancy.

METHODS

A PubMed search was performed for manuscripts in English language from inception till June 2020. Cases of CD with hypercortisolism during pregnancy were included and categorized into three groups based on treatment received. Data on diagnostic modalities, CD remission, materno-fetal outcomes were analysed.

RESULTS

Fifty-five patients of CD with 62 pregnancies were analysed. 24-h urinary free cortisol(UFC) was elevated by a mean of 5.4 ± 4.2 fold upper limit of normal non-pregnant level. 12/19 (63.1%) CD patients had more than threefold elevation of UFC measured during pregnancy. Mean midnight serum cortisol was 753.7 ± 270.5 nmol/l. At a midnight serum cortisol cut off of 440 nmol/l, 15/16 patients were correctly identified as CD. 23.2% underwent trans-sphenoidal surgery (group 1), 16.1% received only medical treatment (group 2) while 60.7% received no treatment (group 3) during pregnancy. Remission rates for CD in groups 1 and 2 were 76.9% and 77.8%, respectively. Adverse maternal and fetal outcomes were seen in 53.9% and 59.3% of the patients, respectively and were not significantly different between groups, although, lesser live births and greater pregnancy losses were seen in group 3.

CONCLUSION

Midnight serum cortisol had better sensitivity than UFC for diagnosing hypercortisolism due to CD during pregnancy. In general, CD should be treated during pregnancy in order to optimize maternal and fetal outcomes as a trend towards increased live births is seen in treated subjects.

Low-dose short synacthen test with salivary cortisol in patients with suspected central adrenal insufficiency

CONTEXT

The low-dose short synacthen test (LDSST) is recommended for patients with suspected central adrenal insufficiency (AI) if their basal serum cortisol (F) levels are not indicative of an intact hypothalamic-pituitary-adrenal (HPA) axis.

OBJECTIVE

To evaluate diagnostic threshold for salivary F before and 30 min after administering 1 μg of synacthen, performed before 09:30 h.

DESIGN

A cross-sectional study from 2014 to 2020.

SETTING

A tertiary referral university hospital.

PATIENTS

In this study, 174 patients with suspected AI, 37 with central AI and 137 adrenal sufficient (AS), were included.

MAIN OUTCOME MEASURE

The diagnostic accuracy (sensitivity (SE), specificity (SP)) of serum and salivary F levels measured, respectively, by chemiluminescence immunoassay and liquid chromatography-tandem mass spectrometry.

RESULTS

Low basal serum or salivary F levels could predict AI. For the LDSST, the best ROC-calculated threshold for serum F to differentiate AI from AS was 427 nmol/L (SE 79%, SP 89%), serum F > 500 nmol/L reached SP 100%. A salivary F peak > 12.1 nmol/L after administering synacthen reached SE 95% and SP 84% for diagnosing central AI, indicating a conclusive reduction in the likelihood of AI. This ROC-calculated threshold for salivary F was similar to the 2.5th percentile of patients with a normal HPA axis, so it was considered sufficient to exclude AI. Considering AS those patients with salivary F > 12.1 nmol/L after LDSST, we could avoid unnecessary glucocorticoid treatment: 99/150 subjects (66%) had an inadequate serum F peak after synacthen, but salivary F was >12.1 nmol/L in 79 cases, who could, therefore, be considered AS.

CONCLUSIONS

Salivary F levels > 12.1 nmol/L after synacthen administration can indicate an intact HPA axis in patients with an incomplete serum F response, avoiding the need to start glucocorticoid replacement treatment.

Two-day low-dose dexamethasone suppression test more accurate than overnight 1-mg in women taking oral contraceptives

Introduction

Late-night salivary cortisol (LSaC) and 24-h urinary free cortisol measurement, and overnight 1-mg dexamethasone suppression test (1 mg-DST) are the first-line screening tests recommended for Cushing's syndrome. Through elevations in the level of cortisol-binding globulin, oral contraceptive agents lead to increases in the total plasma cortisol concentration, yielding false-positive 1 mg-DST results.

Objective

To compare the accuracy of the overnight 1-mg DST and two-day low-dose DST (2d-DST) in female volunteers taking combined oestrogen-progestin oral contraceptives (COCs).

Methods

This prospective study enrolled 30 healthy participants. Their plasma cortisol response levels were compared after the 1-mg DST and 2d-DST and classified into three categories: normal (≤50 nmol/L), doubtful (51-138 nmol/L) and abnormal (>138 nmol/L). Salivary cortisol was also measured at late night and after the DSTs.

Results

Following the 1-mg DST and 2d-DST, the plasma cortisol concentrations decreased to a median of 69 nmol/L and 37 nmol/L, respectively (p < 0.001). A statistically significant higher proportion of unclear or abnormal results were observed after the 1-mg DST (63%) than after the 2d-DST (27%) (p = 0.004). None of the values were >138 nmol/L after the 2d-DST, while 11% of them were abnormal after the 1-mg DST (p = 0.25). No LSaC value was abnormal.

Conclusion

Our results suggest that, when late-night salivary cortisol is not available, the 2d-DST could be a better screening option than the 1-mg DST for women taking oral contraceptive agents who are reluctant to stop them. This finding requires confirmation in those with a suspicion of hypercortisolism.

Bedtime Salivary Cortisol as a Screening Test for Cushing Syndrome in Children

Background

Diagnosing Cushing syndrome (CS) can be challenging. The 24-hour urine free cortisol (UFC) measurement is considered gold standard. This is a laborious test, dependent on correct urine collection. Late-night salivary cortisol is easier and is used as a screening test for CS in adults, but has not been validated for use in children.

Objective

To define liquid chromatography tandem mass spectrometry (LC-MS/MS)-based cutoff values for bedtime and morning salivary cortisol and cortisone in children, and validate the results in children with and without CS.

Methods

Bedtime and morning salivary samples were collected from 320 healthy children aged 4 to 16 years. Fifty-four patients from the children’s outpatient obesity clinic and 3 children with pituitary CS were used for validation. Steroid hormones were assayed by LC-MS/MS. Cutoff levels for bedtime salivary cortisol and cortisone were defined by the 97.5% percentile in healthy subjects.

Results

Bedtime cutoff levels for cortisol and cortisone were 2.4 and 12.0 nmol/L, respectively. Applying these cutoff levels on the verification cohort, 1 child from the obesity clinic had bedtime salivary cortisol exceeding the defined cutoff level, but normal salivary cortisone. All 3 children with pituitary CS had salivary cortisol and cortisone far above the defined bedtime cutoff levels. Healthy subjects showed a significant decrease in salivary cortisol from early morning to bedtime.

Conclusions

We propose that bedtime salivary cortisol measured by LC-MS/MS with a diagnostic threshold above 2.4 nmol/L can be applied as a screening test for CS in children. Age- and gender-specific cutoff levels are not needed.

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.

Stress and Metabolomics for Prediction of Spontaneous Preterm Birth: A Prospective Nested Case-Control Study in a Tertiary Hospital

Spontaneous preterm birth (sPTB) is the leading cause of infant morbidity and mortality worldwide. Deficiency of effective predict methods is an urgent problem that needs to be solved. Numbers of researchers spare no efforts to investigate differential indicators. To evaluate the value of the differential indicators, a prospective nested case-control study was carried out. Among an overall cohort of 1,050 pregnancies, 20 sPTB pregnancies, and 20 full-term pregnancies were enrolled in this study. Participants were followed-up until labor. The psychological profile was evaluated utilizing the Zung Self-Rating Depression Scale at 11-14 weeks. Stress-related biomarker-cortisol and metabolites were detected by Electrochemiluminescence Immunoassay (ECLIA) and Gas Chromatography-Mass Spectrometry (GC-MS) in serum samples during pregnancy, respectively. The expression level of cortisol was up-regulated in serum and the score of the Zung Self-Rating Depression Scale was significantly higher in the sPTB group when compared to the control group. Note that, 29 metabolomics were differentially expressed between the sPTB group and the control group. The scores of the Zung Self-Rating Depression Scale, the level of cortisol, Eicosane, methyltetradecanoate, and stearic acid in serum were selected to establish the model with lasso logistic regression. Validation of the model yielded an optimum corrected AUC value of 89.5%, 95% CI: 0.8006-0.9889 with a sensitivity of 100.0%, and specificity of 78.9%. In conclusion, this study establishes a prediction model of sPTB with five variables, which may predict sPTB more accurately and sensitively in the second trimester.

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 Disease

In patients with Cushing's disease (CD), prompt diagnosis and treatment are essential for favorable long-term outcomes, although this remains a challenging task. The differential diagnosis of CD is still difficult in some patients, even with an organized stepwise diagnostic approach. Moreover, despite the use of high-resolution magnetic resonance imaging (MRI) combined with advanced fine sequences, some tumors remain invisible. Surgery, using various surgical approaches for safe maximum tumor removal, still remains the first-line treatment for most patients with CD. Persistent or recurrent CD after unsuccessful surgery requires further treatment, including repeat surgery, medical therapy, radiotherapy, or sometimes, bilateral adrenalectomy. These treatments have their own advantages and disadvantages. However, the most important thing is that this complex disease should be managed by a multidisciplinary team with collaborating experts. In addition, a personalized and individual-based approach is paramount to achieve high success rates while minimizing the occurrence of adverse events and improving the patients' quality of life. Finally, the recent new insights into the pathophysiology of CD at the molecular level are highly anticipated to lead to the introduction of more accurate diagnostic tests and efficacious therapies for this devastating disease in the near future.

Central adrenal insufficiency: open issues regarding diagnosis and glucocorticoid treatment

Background

Central adrenal insufficiency (CAI) is characterized by impaired adrenocorticotropin (ACTH) secretion because of a disease or injury to the hypothalamus or the pituitary, leading to a reduced cortisol production. CAI suspicion arises more frequently in patients with pituitary tumors, cranial irradiation/surgery/injury/infections, as well as after exogenous glucocorticoid withdrawal. Nevertheless, a late diagnosis is not uncommon because CAI may present with nonspecific signs or symptoms, as fatigue or hyponatremia.

Content

The PubMed database was searched (years 1980–2018), using “central adrenal insufficiency” and “ACTH deficiency” as keywords. Subsequently, reference sections of the retrieved articles were searched.

Summary

Dynamic tests are needed when morning basal cortisol levels are not sufficient to exclude or to confirm CAI. Short Synacthen Test (SST) is the most used, and Endocrine Society’s guidelines recommend a cortisol peak >500 nmol/L to exclude CAI. Despite thresholds, understanding the pretest probability of ACTH deficiency (the clinical background of the patient) is essential because the diagnostic accuracy of SST in case of a negative result is suboptimal. Glucocorticoid replacement therapy, able to replicate cortisol circadian rhythm, is required in patients with CAI; fludrocortisone treatment is not necessary. Short-acting glucocorticoid drugs (hydrocortisone or cortisone acetate) are the most used; lower doses than previously used are nowadays recommended to reduce cortisol-related comorbidities. Promising results have been obtained with modified-release hydrocortisone, especially regarding glucose metabolism in patients with primary adrenal insufficiency.

Outlook

An accurate clinical diagnosis and a careful individualized therapy are mandatory in patients with CAI.

Wearable sensors for monitoring the physiological and biochemical profile of the athlete

Athletes are continually seeking new technologies and therapies to gain a competitive edge to maximize their health and performance. Athletes have gravitated toward the use of wearable sensors to monitor their training and recovery. Wearable technologies currently utilized by sports teams monitor both the internal and external workload of athletes. However, there remains an unmet medical need by the sports community to gain further insight into the internal workload of the athlete to tailor recovery protocols to each athlete. The ability to monitor biomarkers from saliva or sweat in a noninvasive and continuous manner remain the next technological gap for sports medical personnel to tailor hydration and recovery protocols per the athlete. The emergence of flexible and stretchable electronics coupled with the ability to quantify biochemical analytes and physiological parameters have enabled the detection of key markers indicative of performance and stress, as reviewed in this paper.

Clinical translation of biomedical sensors for sports medicine

The digital health field has seen a surge in product development over the last decade, with product introductions ranging from wrist monitors, epidermal electronics, electronic pills and smart garments, much of these precipitated through the commercialisation and commoditisation of sensor technology. The emergence of wearable technology has recently garnered heightened interest by physicians and the general public. The convenient use of wireless technology to track and monitor physiological parameters, such as heart rate, distance, sleep and stress, has emerged to become relevant to patient care and human performance assessment. However, collecting data is not enough to inform clinical decision-making. It is essential to translate the acquired data into information relevant to clinicians. Our experiences tell us that team competencies must mirror the interdisciplinary technology itself. Thus, an interdisciplinary team blending expertise from engineering, medicine, and nursing is believed to be essential in translating wearable technology into the field. This review discusses the application of wearable sensors to monitor human performance assessment in domains necessitating accurate, reliable, and timely transmission of acquired bio-metric and bio-vital data. A key result disseminating from our investigations is the need to develop predictive models based off of the data acquired from wearable devices to necessitate the development of athlete-centred treatment plans to expedite the return-to-play time and to maximise performance.

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.

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.

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.

Cushing's Syndrome in Pediatrics: An Update

Cushing syndrome (CS) is a multisystem disorder resulting from the prolonged exposure to excess glucocorticoids. In children, CS most commonly results from the exogenous administration of steroids and the typical presentation is height deceleration concomitant with weight gain. Endogenous and ectopic causes are rare. CS in children may be associated with distinct germline and somatic mutations. Clinical practice guidelines are available assist clinicians. Patients should be referred to multidisciplinary centers of excellence with experience in endocrinology and surgery. Early detection and treatment is essential to reduce associated acute and long-term morbidity and potential death.

Epidemiology, clinical presentation and diagnosis of non-functioning pituitary adenomas

PURPOSE

Non-functioning pituitary adenomas (NFPAs) are benign pituitary neoplasms that do not cause a hormonal hypersecretory syndrome. An improved understanding of their epidemiology, clinical presentation and diagnosis is needed.

METHOD

A literature review was performed using Pubmed to identify research reports and clinical case series on NFPAs.

RESULTS

They account for 14-54% of pituitary adenomas and have a prevalence of 7-41.3/100,000 population. Their standardized incidence rate is 0.65-2.34/100,000 and the peak occurence is from the fourth to the eighth decade. The clinical spectrum of NFPAs varies from being completely asymptomatic to causing significant hypothalamic/pituitary dysfunction and visual field compromise due to their large size. Most patients present with symptoms of mass effect, such as headaches, visual field defects, ophthalmoplegias, and hypopituitarism but also hyperprolactinaemia due to pituitary stalk deviation and less frequently pituitary apoplexy. Non-functioning pituitary incidentalomas are found on brain imaging performed for an unrelated reason. Diagnostic approach includes magnetic resonance imaging of the sellar region, laboratory evaluations, screening for hormone hypersecretion and for hypopituitarism, and a visual field examination if the lesion abuts the optic nerves or chiasm.

CONCLUSION

This article reviews the epidemiology, clinical behaviour and diagnostic approach of non-functioning pituitary adenomas.

Chemical analysis in saliva and the search for salivary biomarkers – a tutorial review

A review of the uses of saliva biomarkers, detection methods and requirements for new biomarkers.

Simultaneous assay of cortisol and dexamethasone improved diagnostic accuracy of the dexamethasone suppression test

OBJECTIVES

The overnight dexamethasone (DXM) suppression test (DST) has high sensitivity, but moderate specificity, for diagnosing hypercortisolism. We have evaluated if simultaneous measurement of S-DXM may correct for variable DXM bioavailability and increase the diagnostic performance of DST, and if saliva (sa) is a feasible adjunct or alternative to serum.

DESIGN AND METHODS

Prospective study of DST was carried out in patients with suspected Cushing's syndrome (CS) (n = 49), incidentaloma (n = 152) and healthy controls (n = 101). Cortisol, cortisone and DXM were assayed by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

Three hundred and two subjects underwent DST; S-cortisol was ≥50 nmol/L in 83 patients, of whom 11 had CS and 27 had autonomous cortisol secretion. The lower 2.5 percentile of S-DXM in subjects with negative DST (n = 208) was 3.3 nmol/L, which was selected as the DXM cut-off level. Nine patients had the combination of low S-DXM and positive DST. Of these, three had been misdiagnosed as having autonomous cortisol secretion. DST results were highly reproducible and confirmed in a replication cohort (n = 58). Patients with overt CS had significantly elevated post-DST sa-cortisol and sa-cortisone levels compared with controls; 23 of 25 with autonomous cortisol secretion had elevated sa-cortisone and 14 had elevated sa-cortisol.

CONCLUSIONS

Simultaneous measurement of serum DXM and cortisol reduced false-positive DSTs by 20% and improved the specificity. S-DXM >3.3 nmol/L is sufficient for the suppression of cortisol <50 nmol/L. Measurement of glucocorticoids in saliva is a non-invasive and easy procedure and post-DST sa-cortisone was found particularly useful in the diagnosis of CS.

The degree of urinary hypercortisolism is not correlated with the severity of cushing's syndrome

Cushing syndrome (CS) is characterized by increased morbidity and mortality compared to the general population. However, there are patients who have more clinical aggressive forms than others. Aim of the study is to evaluate whether the degree of hypercortisolism, defined by the number of times urinary free cortisol (UFC) levels exceed the upper limit of the normal range (ULN), is related to the worsening of phenotypic features, as well as metabolic and cardiovascular parameters, in a cohort of CS patients. A cross-sectional study was conducted on 192 patients with active CS, consecutively presenting at the outpatients' clinic of the University Hospitals of Ancona, Naples, and Palermo. Patients were grouped into mild (UFC not exceeding twice the ULN), moderate (2-5 times the ULN), and severe (more than 5 times the ULN) hypercortisolism. Thirty-seven patients (19.3 %) had mild, 115 (59.8 %) moderate, and 40 (20.9 %) severe hypercortisolism. A significant trend of increase among the three groups was demonstrated for 8-, 16-, and 24-h serum cortisol levels (p < 0.001) and serum cortisol after low dose of dexamethasone suppression test (p = 0.001). No significant trend of increase was found regarding phenotype and comorbidities. The degree of hypercortisolism by itself does not appear to be a sufficient parameter to express the severity of CS. Therefore, estimating the severity of CS according to biochemical parameters remains a challenge, while the clinical phenotype and the associated comorbidities might be more useful to assessing the severity of the CS.

Quantification of cortisol in human eccrine sweat by liquid chromatography - tandem mass spectrometry

Cortisol has long been recognized as the "stress biomarker" in evaluating stress related disorders. Plasma, urine or saliva are the current source for cortisol analysis. The sampling of these biofluids is either invasive or has reliability problems that could lead to inaccurate results. Sweat has drawn increasing attention as a promising source for non-invasive stress analysis. A sensitive HPLC-MS/MS method was developed for the quantitation of cortisol ((11β)-11,17,21-trihydroxypregn-4-ene-3,20-dione) in human eccrine sweat. At least one unknown isomer that has previously not been reported and could potentially interfere with quantification was separated from cortisol with mixed mode RP HPLC. Detection of cortisol was carried out using atmospheric pressure chemical ionization (APCI) and selected reaction monitoring (SRM) in positive ion mode, using cortisol-9,11,12,12-D4 as internal standard. LOD and LOQ were estimated to be 0.04 ng ml(-1) and 0.1 ng ml(-1), respectively. Linear range of 0.10-25.00 ng ml(-1) was obtained. Intraday precision (2.5%-9.7%) and accuracy (0.5%-2.1%), interday precision (12.3%-18.7%) and accuracy (7.1%-15.1%) were achieved. This method has been successfully applied to the cortisol analysis of human eccrine sweat samples. This is the first demonstration that HPLC-MS/MS can be used for the sensitive and highly specific determination of cortisol in human eccrine sweat in the presence of at least one isomer that has similar hydrophobicity as cortisol. This study demonstrated that human eccrine sweat could be used as a promising source for non-invasive assessment of stress biomarkers such as cortisol and other steroid hormones.

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.

Determination of nighttime salivary cortisol during pregnancy: comparison with values in non-pregnancy and Cushing's disease

PURPOSE

Nighttime salivary cortisol (NSC) has been proposed for the diagnosis of Cushing's syndrome during pregnancy. However, reference values for NCS in pregnant women have not been adequately determined. The aim of this study was to determine the reference values of NSC in the three gestational trimesters in order to help distinguish physiological from pathological hypercortisolism during pregnancy.

METHODS

This prospective and retrospective study evaluated 85 pregnant women in whom samples were collected in the first, second and/or third gestational trimester (pregnancy group), 33 non-pregnant women (control group), and 25 non-pregnant women with Cushing's disease (CD group). NSC was measured by enzyme-linked immunosorbent assay.

RESULTS

NSC increased progressively during pregnancy, reaching maximum levels on the third trimester (median 2.1-fold increase compared with controls, p < 0.001). Reference values for NSC were determined and the upper limits on each gestational trimester were: first trimester 0.25 µg/dL (6.9 nmol/L), second trimester 0.26 µg/dL (7.2 nmol/L), and third trimester 0.33 µg/dL (9.1 nmol/L). Cutoff values that separated the CD group from the three trimesters in the pregnancy groups were, respectively, 0.255 µg/dL (7.0 nmol/L), 0.260 µg/dL (7.2 nmol/L), and 0.285 µg/dL (7.9 nmol/L). Comparison of NSC cutoff values in pregnant women with CD patients showed high sensitivity and specificity in all three trimesters.

CONCLUSIONS

We established cutoff values for determination of NSC which can be useful for pregnant women with a diagnostic suspicion of CD.

Variability in laboratory parameters used for management of Cushing's syndrome

The progress in assay methodology, from the use of radioactive tracers to chemiluminescent signals, from competitive to chromatographic techniques and from serum or urine to saliva has considerably impacted on hormonal measurements. The clinician now may choose among multiple tests but the inherent variability in cortisol and ACTH secretion, coupled to lack of harmonization among assay procedures and normal ranges mandates careful interpretation of any result. The present review will examine factors which affect interpretation of cortisol and ACTH measurements and their impact on tests used for management of Cushing's syndrome.

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.

Cushing's syndrome

Chronic exposure to excess glucorticoids results in diverse manifestations of Cushing's syndrome, including debilitating morbidities and increased mortality. Genetic and molecular mechanisms responsible for excess cortisol secretion by primary adrenal lesions and adrenocorticotropic hormone (ACTH) secretion from corticotroph or ectopic tumours have been identified. New biochemical and imaging diagnostic approaches and progress in surgical and radiotherapy techniques have improved the management of patients. The therapeutic goal is to normalise tissue exposure to cortisol to reverse increased morbidity and mortality. Optimum treatment consisting of selective and complete resection of the causative tumour is necessay to allow eventual normalisation of the hypothalamic-pituitary-adrenal axis, maintenance of pituitary function, and avoidance of tumour recurrence. The development of new drugs offers clinicians several choices to treat patients with residual cortisol excess. However, for patients affected by this challenging syndrome, the long-term effects and comorbidities associated with hypercortisolism need ongoing care.

Cushing's syndrome: update on signs, symptoms and biochemical screening

Endogenous pathologic hypercortisolism, or Cushing's syndrome, is associated with poor quality of life, morbidity, and increased mortality. Early diagnosis may mitigate against this natural history of the disorder. The clinical presentation of Cushing's syndrome varies, in part related to the extent and duration of cortisol excess. When hypercortisolism is severe, its signs and symptoms are unmistakable. However, most of the signs and symptoms of Cushing's syndrome are common in the general population (e.g., hypertension and weight gain) and not all are present in every patient. In addition to classical features of glucocorticoid excess, such as proximal muscle weakness and wide purple striae, patients may present with the associated comorbidities that are caused by hypercortisolism. These include cardiovascular disease, thromboembolic disease, psychiatric and cognitive deficits, and infections. As a result, internists and generalists must consider Cushing's syndrome as a cause, and endocrinologists should search for and treat these comorbidities. Recommended tests to screen for Cushing's syndrome include 1  mg dexamethasone suppression, urine free cortisol, and late night salivary cortisol. These may be slightly elevated in patients with physiologic hypercortisolism, which should be excluded, along with exogenous glucocorticoid use. Each screening test has caveats and the choice of tests should be individualized based on each patient's characteristics and lifestyle. The objective of this review is to update the readership on the clinical and biochemical features of Cushing's syndrome that are useful when evaluating patients for this diagnosis.

Evaluation of steroidomics by liquid chromatography hyphenated to mass spectrometry as a powerful analytical strategy for measuring human steroid perturbations

This review presents the evolution of steroid analytical techniques, including gas chromatography coupled to mass spectrometry (GC-MS), immunoassay (IA) and targeted liquid chromatography coupled to mass spectrometry (LC-MS), and it evaluates the potential of extended steroid profiles by a metabolomics-based approach, namely steroidomics. Steroids regulate essential biological functions including growth and reproduction, and perturbations of the steroid homeostasis can generate serious physiological issues; therefore, specific and sensitive methods have been developed to measure steroid concentrations. GC-MS measuring several steroids simultaneously was considered the first historical standard method for analysis. Steroids were then quantified by immunoassay, allowing a higher throughput; however, major drawbacks included the measurement of a single compound instead of a panel and cross-reactivity reactions. Targeted LC-MS methods with selected reaction monitoring (SRM) were then introduced for quantifying a small steroid subset without the problems of cross-reactivity. The next step was the integration of metabolomic approaches in the context of steroid analyses. As metabolomics tends to identify and quantify all the metabolites (i.e., the metabolome) in a specific system, appropriate strategies were proposed for discovering new biomarkers. Steroidomics, defined as the untargeted analysis of the steroid content in a sample, was implemented in several fields, including doping analysis, clinical studies, in vivo or in vitro toxicology assays, and more. This review discusses the current analytical methods for assessing steroid changes and compares them to steroidomics. Steroids, their pathways, their implications in diseases and the biological matrices in which they are analysed will first be described. Then, the different analytical strategies will be presented with a focus on their ability to obtain relevant information on the steroid pattern. The future technical requirements for improving steroid analysis will also be presented.

The evaluation and treatment of endocrine forms of hypertension

Endocrine hypertension is an important secondary form of hypertension, identified in between 5% and 10% of general hypertensive population. Primary aldosteronism is the most common cause of endocrine hypertension, accounting for 1%-10% in uncomplicated hypertension and 7%-20% in resistant hypertension. Other less common causes of endocrine hypertension include Cushing syndrome, pheochromocytoma, thyroid disorders, and hyperparathyroidism. Diagnosis requires a high index of suspicion and the use of appropriate screening tests based on clinical presentation. Failure to make proper diagnosis may lead to catastrophic complications or irreversible hypertensive target organ damage. Accordingly, patients who are suspected to have endocrine hypertension should be referred to endocrinologists or hypertension specialists who are familiar with management of the specific endocrine disorders.

Pituitary tumor management in pregnancy

The improved management of pituitary adenomas has led to an increasing number of pregnancies in patients harboring pituitary adenomas. Therefore, adequate management of pregnant women with pituitary adenomas is of growing importance. Because pregnancy produces several physiologic changes to the endocrine system, especially to the pituitary gland, endocrinologists must be knowledgeable and skilled to effectively manage pregnant women with pituitary adenomas and to guarantee the wellbeing of the fetus.

Cushing syndrome: update on testing

Endogenous hypercortisolism (Cushing syndrome) is one of the most enigmatic diseases in clinical medicine. The diagnosis and differential diagnosis of Cushing syndrome depend on proper laboratory evaluation. In this review, an update is provided on selected critical issues in the diagnosis and differential diagnosis of Cushing syndrome: the use of late-night salivary cortisol in initial diagnosis and for postoperative surveillance, and the use of prolactin measurement to improve the performance of inferior petrosal sinus sampling to distinguish Cushing disease from ectopic adrenocorticotropic hormone (ACTH) syndrome during differential diagnosis of ACTH-dependent Cushing syndrome.

Late-night salivary cortisol has a better performance than urinary free cortisol in the diagnosis of Cushing's syndrome

CONTEXT

The comparison of variability, reproducibility, and diagnostic performance of late-night salivary cortisol (LNSF) and urinary free cortisol (UFC) using concurrent and consecutive samples in Cushing's syndrome (CS) is lacking. Objectives, Patients, and Methods: In a prospective study, we evaluated 3 simultaneous and consecutive samples of LNSF by RIA and UFC by liquid chromatography associated with tandem mass spectrometry in Cushing's disease (CD) patients (n = 43), adrenal CS patients (n = 9), and obese subjects (n = 18) to compare their diagnostic performances. In CS patients, we also performed a modified CS severity index.

RESULTS

There was no difference in the coefficient of variation (percentage) between LNSF and UFC among the 3 samples obtained for each patient with Cushing's disease (35 ± 26 vs 31 ± 24), adrenal CS (28 ± 14 vs 22 ± 14), and obesity (39 ± 37 vs 48 ± 20). LNSF confirmed the diagnosis of hypercortisolism even in the presence of normal UFC in 17.3% of CS, whereas the inverse situation was not observed for UFC. The area under the receiver-operating characteristic curves for LNSF was 0.999 (95% credible interval [CI] 0.990-1.00) and for UFC was 0.928 (95% CI 0.809-0.987). The ratio between areas under the curve was 0.928 (95% CI 0.810-0.988), indicating better performance of LNSF than UFC in diagnosing CS. There was no association between the CS severity index and the degree of biochemical hypercortisolism.

CONCLUSION

Our data show that despite similar variability between both methods, LNSF has a superior diagnostic performance than UFC and should be used as the primary biochemical diagnostic test for CS diagnosis.

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.

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.