Specificity of screening tests for Cushing's syndrome in an overweight and obese population

Cushing's syndrome screening with the 1-mg dexamethasone suppression test in metabolically healthy and unhealthy obesity phenotypes

BACKGROUND

The ongoing debate regarding the need for screening Cushing's syndrome (CS) in patients with obesity continues. The objectives of this study were to establish the prevalence of CS in the population with obesity and assess how metabolic health status influences cortisol levels following the 1 mg dexamethasone suppression test (DST).

METHODS

This retrospective study included 1008 patients with obesity who underwent screening with the 1 mg DST for CS. These patients were categorized into two groups as metabolically healthy obesity (MHO) and unhealthy obesity (MUO).

RESULTS

Out of the 1008 patients, 779 (77.3%) belonged to the MUO group. Within the entire study cohort, 12 (1.2%) patients exhibited a cortisol level of ≥ 1.8 after the 1 mg DST. Cortisol levels following the 1 mg DST were also significantly higher in the MUO group than in the MHO group (p = 0.001). Among these 12 patients, 11 were presenting a MUO phenotype. Hypercortisolism was definitively diagnosed in two patients, resulting in an overall prevalence of 0.2%. The 1 mg DST demonstrated a specificity of 99% and 100% sensitivity for screening for CS.

CONCLUSIONS

While the 1 mg DST is a practical screening test for CS with high specificity in obesity, the number of CS cases detected remains relatively low. Therefore, it may be more reasonable and applicable to screen patients with MUO phenotype rather than all individuals with obesity.

Nocturnal Salivary Cortisol Is an Accurate Non-Invasive Test to Assess Endogenous Hypercortisolism in Children with Obesity and a Clinical Phenotype Suspicious for Cushing's Syndrome

INTRODUCTION

Cushing's syndrome (CS) constitutes one of the most challenging diagnostic assessments for paediatric endocrinologists. The clinical presentation of some children with exogenous obesity overlaps with those observed in hypercortisolism states. Accurate, non-invasive first-line tests are necessary to avoid false-positive results in the obese. We aimed to evaluate the diagnostic accuracy of salivary cortisol to assess endogenous hypercortisolism in children with obesity and clinical overlapping signs of CS.

METHODS

Case-control study that included children aged 2-18 years, BMI-SDS ≥2.0 and a follow-up >2 years. Patients were assigned to three categories: group A, features strongly indicative of paediatric CS (growth failure combined with increasing weight); group B, features suggestive of CS (e.g., moon face and striae); and group C, less specific features overlapping with CS (e.g., hypertension, hirsutism, insulin resistance). Children in categories A and B formed the control group. Ten patients with confirmed CS were the case group. All children collected saliva samples on the same day in the morning between 7 and 8:00 a.m. (morning salivary cortisol: mSC) and at 11 p.m. (nocturnal salivary cortisol: nSC). The mSC and nSC results were used to calculate the percentage decrease of cortisol at night (%D). Main outcomes by receiver operating characteristic for nSC and the %D were sensitivity, specificity, positive (P) and negative (N) predictive values (PV) and their corresponding 95% CI. Salivary cortisol was measured by electrochemiluminescence assay (lower limit of quantification: 2.0 nmol/L).

RESULTS

75/112 children met the inclusion criteria, whereas 22/75 children were eligible for the control group. Only controls decreased nSC (median and interquartile range: 2.0 [2.0-2.5] nmol/L) compared to mSC (6.9 [4.8-10.4] nmol/L), p < 0.0001. A cut-off for nSC ≥8 nmol/L confirmed CS within a sensitivity: 1.0 (0.69-1.0), specificity: 1.0 (0.85-1.0), PPV: 1.0 (0.69-0.99), and NPV: 1.0(0.85-0.99), achieving a diagnostic efficiency of 100%. The cut-off obtained for %D was 50%. No child with CS had a %D ≥50%, but 6/22 children in the control group had a %D below the cut-off, resulting in a lower overall diagnostic accuracy of 81% compared to nSC.

CONCLUSION

Salivary cortisol at 11 p.m. is an accurate, feasible, and non-invasive first-line test to assess endogenous hypercortisolism in children with obesity and clinical suspicion of CS. The nSC was also useful in showing that the circadian rhythm of cortisol was preserved in children with exogenous obesity. In patients with nSC ≥8.0 nmol/L, other biochemical assessments and imaging studies are needed to further confirm the aetiology.

Severe Acute Pancreatitis Rapidly Developed Into Pulmonary Edema and Diffuse Alveolar Hemorrhage Leading to Respiratory Failure: An Autopsy Case

Acute pancreatitis often results in life-threatening situations, making a prompt and accurate diagnosis cardinally important. To achieve these, it is crucial to correctly identify characteristic symptoms and test findings. However, when patients do not exhibit distinctive symptoms during a physician's examination, in addition to limited resources, these can become challenging. In this manuscript, we present an instructive case. A male in his twenties, who complained of generalized malaise, was admitted to our hospital. Unfortunately, however, he passed away within two days prior to undergoing detailed examinations or receiving therapeutic interventions. We performed an autopsy in order to ascertain the reasons for this outcome. The findings revealed that pulmonary edema and diffuse alveolar hemorrhage were the causative factors of his demise, with acute pancreatitis observed in the background. The occurrence of acute pancreatitis leading to death in youths is infrequent. Where could we have intervened to halt such an unfortunate course in a young individual? This patient probably had diabetic ketoacidosis and hyperlipidemia, both of which are known to be closely associated with acute pancreatitis. In retrospect, we should have noticed this point. In this case, the condition progressed too rapidly for appropriate therapeutic interventions. We believe that this case would provide educational instruction for similar situations that could arise in the future.

The Role of Serum Inflammation-Based Scores in Diagnosis and Assessing Remission in Cushing's Disease

Objectives

Chronic hypercortisolism causes diverse alterations in the immune system and inflammatory disruptions. Serum inflammation-based scores (SIBS) are indicators of systemic inflammatory status. This study aims to determine the role of SIBS in the diagnosis and evaluation of remission in patients with Cushing's disease (CD).

Methods

This retrospective cross-sectional study was conducted on 195 participants; 52 patients diagnosed and followed up after treatment with CD, 65 patients with subclinical Cushing's syndrome (SCS), and 78 healthy individuals whose complete blood counts (CBC) were obtained for analysis. Participants with additional diseases or drug use that could affect CBC were excluded from the study. SIBS of the three groups were compared. Scores considered were neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII). The correlations between SIBS and initial diagnostic tests for hypercortisolism were analyzed. The SIBS of patients with CD at the diagnosis were compared with those after remission. In addition, receiver operator characteristic curve analyses were used to determine the diagnostic accuracy, specificity, and sensitivity of the scores significantly high in the CD group.

Results

MLR and SII values were significantly higher in CD patients than in the healthy group (p<0.01). NLR and SII were significantly higher in patients with CD than those with SCS (p<0.05). There were no significant differences between the SCS and the control groups in all SIBS. We determine significant, positive, and moderately correlated findings between SIBS and initial diagnostic tests for hypercortisolism in the CD group (0.30

Conclusion

The SIBS, which can be easily calculated with the data obtained from CBC and do not have additional costs, can contribute to the diagnosis and assessment of remission in patients with CD.

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Key Words

• Cushing’s disease
• monocyte-to-lymphocyte ratio
• neutrophil-to-lymphocyte ratio
• platelet-to-lymphocyte ratio
• serum inflammation-based scores
• systemic immune-inflammation index

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MESH Headings Collapse

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Affiliation(s)

Muhammed Masum Canat Department of Endocrinology and Metabolism, University of Health Sciences Türkiye, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye
Ceren Yarkutay Turkkan Department of Internal Medicine, University of Health Sciences Türkiye, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye
Hazan Erhan Department of Internal Medicine, University of Health Sciences Türkiye, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye
Feyza Yener Ozturk Department of Endocrinology and Metabolism, University of Health Sciences Türkiye, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye
Yuksel Altuntas Department of Endocrinology and Metabolism, University of Health Sciences Türkiye, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye

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Effects of very low-calorie ketogenic diet on hypothalamic-pituitary-adrenal axis and renin-angiotensin-aldosterone system

BACKGROUND

The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system involved in controlling stress responses in humans under physiological and pathological conditions; cortisol is the main hormone produced by the HPA axis. It is known that calorie restriction acts as a stressor and can lead to an increase in cortisol production. Renin-angiotensin-aldosterone system (RAAS) is a complex endocrine network regulating blood pressure and hydrosaline metabolism, whose final hormonal effector is aldosterone. RAAS activation is linked to cardiometabolic diseases, such as heart failure and obesity. Obesity has become a leading worldwide pandemic, associated with serious health outcomes. Calorie restriction represents a pivotal strategy to tackle obesity. On the other hand, it is well known that an increased activity of the HPA may favour visceral adipose tissue expansion, which may jeopardize a successful diet-induced weight loss. Very low-calorie ketogenic diet (VLCKD) is a normoprotein diet with a drastic reduction of the carbohydrate content and total calorie intake. Thanks to its sustained protein content, VLCKD is extremely effective to reduce adipose tissue while preserving lean body mass and resting metabolic rate.

PURPOSE

The purpose of this narrative review is to gain more insights on the effects of VLCKD on the HPA axis and RAAS, in different phases of weight loss and in different clinical settings.

Molecular Derangements and the Diagnosis of ACTH-Dependent Cushing's Syndrome

Endogenous Cushing's syndrome (CS) is associated with morbidities (diabetes, hypertension, clotting disorders) and shortens life because of infections, pulmonary thromboembolism, and cardiovascular disease. Its clinical presentation is immensely variable, and diagnosis and treatment are often delayed. Thus, there are many opportunities for basic and clinical research leading to better tests, faster diagnosis, and optimized medical treatments. This review focuses on CS caused by excessive adrenocorticotropin (ACTH) production. It describes current concepts of the regulation of ACTH synthesis and secretion by normal corticotropes and mechanisms by which dysregulation occurs in corticotrope (termed "Cushing's disease") and noncorticotrope (so-called ectopic) ACTH-producing tumors. ACTH causes adrenal gland synthesis and pulsatile release of cortisol; the excess ACTH in these forms of CS leads to the hypercortisolism of endogenous CS. Again, the differences between healthy individuals and those with CS are highlighted. The clinical presentations and their use in the interpretation of CS screening tests are described. The tests used for screening and differential diagnosis of CS are presented, along with their relationship to cortisol dynamics, pathophysiology, and negative glucocorticoid feedback regulation in the two forms of ACTH-dependent CS. Finally, several gaps in current understanding are highlighted in the hope of stimulating additional research into this challenging disorder.

Whom Should We Screen for Cushing Syndrome? The Endocrine Society Practice Guideline Recommendations 2008 Revisited

CONTEXT

Cushing syndrome (CS) is a rare and serious disease with high mortality. Patients are often diagnosed late in the course of the disease.

OBJECTIVE

This work investigated whether defined patient populations should be screened outside the at-risk populations defined in current guidelines.

METHODS

As part of the prospective German Cushing registry, we studied 377 patients with suspected CS. The chief complaint for CS referral was documented. Using urinary free cortisol, late-night salivary cortisol, and the 1-mg dexamethasone suppression test as well as long-term clinical observation, CS was confirmed in 93 patients and ruled out for the remaining 284.

RESULTS

Patients were referred for 18 key symptoms, of which 5 were more common in patients with CS than in those in whom CS was ruled out: osteoporosis (8% vs 2%; P = .02), adrenal incidentaloma (17% vs 8%, P = 0.01), metabolic syndrome (11% vs 4%; P = .02), myopathy (10% vs 2%; P < .001), and presence of multiple symptoms (16% vs 1%; P < .001). Obesity was more common in patients in whom CS was ruled out (30% vs 4%, P < .001), but recent weight gain was prominent in those with CS. A total of 68 of 93 patients with CS (73%) had typical chief complaints, as did 106 of 284 of patients with ruled-out CS status (37%) according to the Endocrine Society practice guideline 2008.

CONCLUSION

The 2008 Endocrine Society Practice guideline for screening and diagnosis of CS defined at-risk populations that should undergo testing. These recommendations are still valid in 2022.

Clinical presentation and etiology of Cushing's syndrome: Data from ERCUSYN

This review presents the data on clinical presentation at diagnosis in 1564 patients included in the European Registry on Cushing's syndrome (ERCUSYN), of whom 1045 (67%) had pituitary-dependent Cushing's syndrome (CS) (PIT-CS), 385 (25%) had adrenal dependent CS (ADR-CS) and 89 (5%) had ectopic adrenocorticotropic hormone syndrome (ECT-CS). The most frequent symptoms in the overall series were weight gain (83%), hypertension (79%), skin alterations (76%) and myopathy (70%). Diabetes mellitus was present in 32% and depression in 35% of patients. Skin alterations, menstrual irregularities and reduced libido were more prevalent in PIT-CS patients compared to ADR-CS patients, whereas patients with ECT-CS more frequently had diabetes mellitus, myopathy, hirsutism and vertebral fractures compared to the other etiologies, consistent with a more severe clinical scenario. Reduced libido and bone fractures were more prevalent in men compared to women. Quality of life was poor at diagnosis, irrespective of the etiology of CS, and also associated with the presence of depression at baseline. A delay of 2 years between the onset of symptoms and diagnosis was also observed, with a high number of specialists consulted, who often missed the correct diagnosis. To develop strategies aimed at shortening the time elapsed to diagnosis, it is important to rapidly start treatment and reduce the burden of the disease on patient psychophysical health and longevity.

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.

The promising role of risk scoring system for Cushing syndrome: Time to reconsider current screening recommendations

Despite the current screening approach for Cushing syndrome (CS), delayed diagnosis is common due to broad spectrum of presentation, poor discriminant symptoms featured in diabetes and obesity, and low clinical index of suspicion. Even if initial tests are recommended to screen CS, divergent results are not infrequent. As global prevalence of type 2 diabetes and obesity increases, CS may not be frequent enough to back routine screening to avoid false-positive results. This represents a greater challenge in countries with limited health resources. The development of indexes incorporates clinical features and biochemical data that are largely used to provide a tool to predict the presence of disease. In clinical endocrinology, indexes have been used in Graves' ophthalmology, hirsutism, and hypothyroidism. The use of clinical risk scoring system may assist clinicians in discriminating CS in the context of at-risk populations and, thus, may provide a potential intervention to decrease time to diagnosis. Development and validation of clinical model to estimate pre-test probability of CS in different geographic source population may help to establish regional prediction model for CS. Here, we review on the latest progress in clinical risk scoring system for CS and attempt to raise awareness for the use, validation, and/or development of clinical risk scores in CS.

Hypercortisolism and altered glucose homeostasis in obese patients in the pre-bariatric surgery assessment

AIMS

Hypothalamus-pituitary-adrenal (HPA) axis hyperactivity was suggested to be associated with the metabolic syndrome (MS), obesity and diabetes. The aim of this study was to test whether hypercortisolism was associated with altered glucose homeostasis and insulin resistance, hypertension and dyslipidemia in a homogeneous population of obese patients.

MATERIALS/METHODS

In retrospective analysis of a set of data about obese patients attending the outpatient service of a single obesity centre between January 2013 and January 2020, 884 patients with BMI >30 kg/m² were segregated in two subgroups: patients with urinary free cortisol (UFC) higher than normal (UFC+; n = 129) or within the normal range (UFC-; n = 755).

RESULTS

The overall prevalence of UFC+ was 14.6% and double test positivity (morning cortisol >1.8 mcg/dL following overnight dexamethasone suppression test, ODST) was detected in 1.0% of patients. Prediabetes (OR 1.74; 95%CI 1.13-2.69; p = 0.012) and diabetes (OR 2.03; 95%CI 1.21-3.42; p = 0.008) were associated with higher risk of UFC+ when analysis was adjusted for confounding variables. Conversely, hypertension and dyslipidemia were not related to UFC+. Within the individuals with normal FPG and HbA1c, those with higher estimated insulin resistance (HOMA2-IR) maintained a higher risk of UFC+ (OR 2.84, 95%CI 1.06-7.63; p = 0.039) and this relationship was weakened only when the body fat percentage was included into the model.

CONCLUSIONS

In obese patients, hypercortisolism was more frequent across the entire spectrum of altered glucose homeostasis including the very early stages; this relation could not be detected for the other criteria of the MS, as waist, hypertension and atherogenic dyslipidemia.

Pituitary-adrenal axis and peripheral cortisol metabolism in obese patients

BACKGROUND AND AIM

A close relationship between adiposity and increased cortisol levels is well established in patients with endogenous hypercortisolism. Nevertheless, hypothalamic-pituitary-adrenal (HPA) axis regulation in overweight subjects is still a matter of concern. We studied free cortisol (urinary free cortisol, UFC and late night salivary cortisol, LNSC), pituitary feedback (serum cortisol after 1 mg dexamethasone suppression test, 1 mg DST) and peripheral cortisol metabolism (urinary cortisol to cortisone ratio, F/E^ratio) in a large series of overweight subjects without Cushing's Syndrome.

MATERIALS AND METHODS

We considered 234 patients divided in 5 BMI classes, matched for age and gender (BMI ≤ 25 kg/m²n = 38; 25-30 n = 58; 30-35 n = 52; 35-40 n = 52; >40 n = 34). UFC, LNSC and urinary F/E^ratio were assessed with LC-MS.

RESULTS

We collected 183 LNSC, 176 UFC, 152 1 mg DST and 64 F/E^ratio tests. UFC levels were higher in lean subjects, and they decreased according to the BMI classes (p = 0.022). Non-suppressed cortisol levels (>50 nmol/L) after 1 mg DST were observed especially in patients with normal weight or mild obesity. Patients with BMI ≥ 35 kg/m² revealed a reduced F/E^ratio (0.39 vs. 0.61, p = 0.006). The specificity of tests (false positive results) was higher considering 1 mg DST or UFC in obese patients, on the contrary impaired cortisol rhythm (LNSC above normality) was observed in 47 subjects, irrespective of weight.

CONCLUSIONS

Overweight and obese subjects are characterised by an original regulation of HPA axis (reduced UFC levels, increased suppression after 1 mg DST) and peripheral cortisol metabolism (reduced F/E^ratio), suggesting an effort to counteract hypercortisolism.

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.

Lack of adipose-specific hexose-6-phosphate dehydrogenase causes inactivation of adipose glucocorticoids and improves metabolic phenotype in mice

Excessive glucocorticoid (GC) production in adipose tissue promotes the development of visceral obesity and metabolic syndrome (MS). 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is critical for controlling intracellular GC production, and this process is tightly regulated by hexose-6-phosphate dehydrogenase (H6PDH). To better understand the integrated molecular physiological effects of adipose H6PDH, we created a tissue-specific knockout of the H6PDH gene mouse model in adipocytes (adipocyte-specific conditional knockout of H6PDH (H6PDHAcKO) mice). H6PDHAcKO mice exhibited almost complete absence of H6PDH expression and decreased intra-adipose corticosterone production with a reduction in 11β-HSD1 activity in adipose tissue. These mice also had decreased abdominal fat mass, which was paralleled by decreased adipose lipogenic acetyl-CoA carboxylase (ACC) and ATP-citrate lyase (ACL) gene expression and reduction in their transcription factor C/EBPα mRNA levels. Moreover, H6PDHAcKO mice also had reduced fasting blood glucose levels, increased glucose tolerance, and increased insulin sensitivity. In addition, plasma free fatty acid (FFA) levels were decreased with a concomitant decrease in the expression of lipase adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) in adipose tissue. These results indicate that inactivation of adipocyte H6PDH expression is sufficient to cause intra-adipose GC inactivation that leads to a favorable pattern of metabolic phenotypes. These data suggest that H6PDHAcKO mice may provide a good model for studying the potential contributions of fat-specific H6PDH inhibition to improve the metabolic phenotype in vivo. Our study suggests that suppression or inactivation of H6PDH expression in adipocytes could be an effective intervention for treating obesity and diabetes.

THE MULTIFARIOUS CUSHING'S - LESSONS FROM A CASE SERIES

Endogenous Cushing's syndrome is rare, with an incidence of 0.7-2.4 per a million people a year. Clinical presentation of Cushing syndrome can be pleomorphic, and establishing diagnosis can be difficult. Early recognition and rapid control of hypercortisolaemia are necessary to decrease morbidity and mortality in these patients. We report a series of 6 endogenous Cushing's syndromes of different etiologies (4 Cushing's disease and 2 adrenal Cushing's syndrome) assessed in our endocrine department over a decade (2009-2019). In order to highlight the diversity of clinical forms, diagnostic tools and specific management of this condition we labelled each case suggestively: the typical Cushing's disease, the Pseudo Cushing's, the elusive Cushing's disease, the mild autonomous cortisol hypersecretion, Cushing's syndrome in pregnancy and Cushing's disease with thromboembolism. We discussed their particularities which were revelatory for the diagnosis, such as dermatologic, cardiovascular, musculoskeletal, neuropsychiatric, or reproductive signs, reviewing literature for each manifestation. We also discuss the commonalities and differences in laboratory and imagistic findings. Therapeutic approach can also differ with respect to the particular condition of each patient and the multiple choices of therapy will be reviewed.

Toward a Diagnostic Score in Cushing's Syndrome

Cushing's syndrome (CS) is a classical rare disease: it is often suspected in patients who do not have the disease; at the same time, it takes a mean of 3 years to diagnose CS in affected individuals. The main reason is the extreme rarity (1-3/million/year) in combination with the lack of a single lead symptom. CS has to be suspected when a combination of signs and symptoms is present, which together make up the characteristic phenotype of cortisol excess. Unusual fat distribution affecting the face, neck, and trunk; skin changes including plethora, acne, hirsutism, livid striae, and easy bruising; and signs of protein catabolism such as thinned and vulnerable skin, osteoporotic fractures, and proximal myopathy indicate the need for biochemical screening for CS. In contrast, common symptoms like hypertension, weight gain, or diabetes also occur quite frequently in the general population and per se do not justify biochemical testing. First-line screening tests include urinary free cortisol excretion, dexamethasone suppression testing, and late-night salivary cortisol measurements. All three tests have overall reasonable sensitivity and specificity, and first-line testing should be selected on the basis of the physiologic conditions of the patient, drug intake, and available laboratory quality control measures. Two normal test results usually exclude the presence of CS. Other tests and laboratory parameters like the high-dose dexamethasone suppression test, plasma ACTH, the CRH test, and the bilateral inferior petrosal sinus sampling are not part of the initial biochemical screening. As a general rule, biochemical screening should only be performed if the pre-test probability for CS is reasonably high. This article provides an overview about the current standard in the diagnosis of CS starting with clinical scores and screenings, the clinical signs, relevant differential diagnoses, the first-line biochemical screening, and ending with a few exceptional cases.

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.

Should Cushing's Syndrome be Considered as a Disease with High Cardiovascular Risk in Relevant Guidelines?

A considerable amount of data supports a 1.8-7.4-fold increased mortality associated with Cushing's syndrome (CS). This is attributed to a high occurrence of several cardiovascular disease (CVD) risk factors in CS [e.g. adiposity, arterial hypertension (AHT), dyslipidaemia and type 2 diabetes mellitus (T2DM)]. Therefore, practically all patients with CS have the metabolic syndrome (MetS), which represents a high CVD risk. Characteristically, despite a relatively young average age, numerous patients with CS display a 'high' or 'very high' CVD risk (i.e. risk of a major CVD event >20% in the following 10 years). Although T2DM is listed as a condition with a high CVD risk, CS is not, despite the fact that a considerable proportion of the CS population will develop T2DM or impaired glucose tolerance. CS is also regarded as a risk factor for aortic dissection in current guidelines. This review considers the evidence supporting listing CS among high CVD risk conditions.

Diagnosis of Cushing's Syndrome in the Modern Era

Four challenges complicate the evaluation for Cushing syndrome. These challenges include increasing global prevalence of obesity and diabetes; increasing use of exogenous glucocorticoids, which cause a Cushing syndrome phenotype; the confusion caused by nonpathologic hypercortisolism not associated with Cushing syndrome, which may present with symptoms consistent with Cushing syndrome; and difficulty identifying pathologic hypercortisolism when it is extremely mild or cyclic or in renal failure, incidental adrenal masses, and pregnancy. Careful choice of screening tests, consideration of confounding conditions, and repeated testing when the results are ambiguous improve the accuracy of diagnosis.

Recent Updates on the Diagnosis and Management of Cushing's Syndrome

Cushing's syndrome, a potentially lethal disorder characterized by endogenous hypercortisolism, may be difficult to recognize, especially when it is mild and the presenting features are common in the general population. However, there is a need to identify the condition at an early stage, as it tends to progress, accruing additional morbidity and increasing mortality rates. Once a clinical suspicion is raised, screening tests involve timed measurement of urine, serum or salivary cortisol at baseline or after administration of dexamethasone, 1 mg. Each test has caveats, so that the choice of tests must be individualized for each patient. Once the diagnosis is established, and the cause is determined, surgical resection of abnormal tumor/tissue is the optimal treatment. When this cannot be achieved, medical treatment (or bilateral adrenalectomy) must be used to normalize cortisol production. Recent updates in screening for and treating Cushing's syndrome are reviewed here.

How useful is urinary-free cortisol in the clinic?

Measurement of 24-h urine-free cortisol is frequently employed as a first-line screening and disease-monitoring test in Cushing's syndrome (CS). The quest for ‘cortisol specificity’ has seen the emergence of mass spectrometry (MS) based assays, particularly liquid chromatography/tandem mass spectrometry. In contrast to traditional immunoassays, liquid chromatography/tandem mass spectrometry ‘free cortisol’ measurement is less susceptible to ‘interference’ from cortisol precursors and metabolites. However, detection of these conjugates is important in mild CS and therefore, missed by MS if cortisol alone is measured. MS assays nevertheless are capable of measuring broad steroid profiles, including the potential to distinguish benign from malignant adrenal-based CS and detection of exogenous glucocorticoids. Until this is routine practice, we recommend against abandoning immunoassays measurement of urine-free cortisol.

AN INDIVIDUALIZED APPROACH TO THE EVALUATION OF CUSHING SYNDROME

Cushing syndrome (CS) is caused by chronic exposure to excess glucocorticoids. Early recognition and treatment of hypercortisolemia can lead to decreased morbidity and mortality. The diagnosis of CS and thereafter, establishing the cause can often be difficult, especially in patients with mild and cyclic hypercortisolism. Surgical excision of the cause of excess glucocorticoids is the optimal treatment for CS. Medical therapy (steroidogenesis inhibitors, medications that decrease adrenocorticotropic hormone [ACTH] levels or glucocorticoid antagonists) and pituitary radiotherapy may be needed as adjunctive treatment modalities in patients with residual, recurrent or metastatic disease, in preparation for surgery, or when surgery is contraindicated. A multidisciplinary team approach, individualized treatment plan and long-term follow-up are important for optimal management of hypercortisolemia and the comorbidities associated with CS.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone; BIPSS = bilateral inferior petrosal sinus sampling; CBG = corticosteroid-binding globulin; CD = Cushing disease; CRH = corticotropin-releasing hormone; CS = Cushing syndrome; Dex = dexamethasone; DST = dexamethasone suppression test; EAS = ectopic ACTH syndrome; FDA = U.S. Food & Drug Administration; HDDST = high-dose DST; IPS/P = inferior petrosal sinus to peripheral; MRI = magnetic resonance imaging; NET = neuroendocrine tumor; PET = positron emission tomography; UFC = urinary free cortisol.

Incidence of Cushing's syndrome in patients with significant hypercortisoluria

OBJECTIVE

To investigate the incidence of Cushing's syndrome (CS) in patients with significant hypercortisoluria and the performance of urinary free cortisol (UFC) screening.

DESIGN

Retrospective file review.

METHODS

The computerized database of a publicly funded health maintenance organization (HMO) in Israel was searched for all patients who underwent 24-h UFC testing in 2005-2014 with a result of more than twice the upper limit of normal (ULN). The patients' medical files were reviewed for a subsequent diagnosis of CS by an expert endocrinologist. Findings were evaluated for patterns in CS diagnosis and UFC testing over time.

RESULTS

Of 41 183 individuals tested, 510 (1.2%) had UFC >2× ULN (214 >3× ULN). Eighty-five (16.7%) individuals were diagnosed with CS (63 female and mean age 47.2 ± 15.1 years), mainly Cushing's disease (55.3%) or adrenal Cushing's syndrome (37.6%). The number of UFC tests increased steadily, from 1804 in 2005 to 6464 in 2014; yet, the resultant detection rate of CS remained generally stable. The calculated incidence of CS in the general HMO-insured population based only on the patients identified in the present cohort was 4.5 new cases/million/year (median 4.9/million/year, range 1.7-5.9/million/year), which was also relatively stable. The most common reason for referral for UFC screening was obesity. Of the 148 patients before bariatric surgery with UFC >2× ULN, 2 were diagnosed with CS.

CONCLUSIONS

The incidence of CS is higher than previously suggested. The consistently increasing number of UFC tests being performed has not been accompanied by a similar increase in CS detection rate. The expected yield of routine UFC testing before bariatric surgery is low.

A Probabilistic Model for Cushing's Syndrome Screening in At-Risk Populations: A Prospective Multicenter Study

CONTEXT

Cushing's syndrome (CS) is challenging to diagnose. Increased prevalence of CS in specific patient populations has been reported, but routine screening for CS remains questionable. To decrease the diagnostic delay and improve disease outcomes, simple new screening methods for CS in at-risk populations are needed.

OBJECTIVE

To develop and validate a simple scoring system to predict CS based on clinical signs and an easy-to-use biochemical test.

DESIGN

Observational, prospective, multicenter.

SETTING

Referral hospital.

PATIENTS

A cohort of 353 patients attending endocrinology units for outpatient visits.

INTERVENTIONS

All patients were evaluated with late-night salivary cortisol (LNSC) and a low-dose dexamethasone suppression test for CS.

MAIN OUTCOME MEASURES

Diagnosis or exclusion of CS.

RESULTS

Twenty-six cases of CS were diagnosed in the cohort. A risk scoring system was developed by logistic regression analysis, and cutoff values were derived from a receiver operating characteristic curve. This risk score included clinical signs and symptoms (muscular atrophy, osteoporosis, and dorsocervical fat pad) and LNSC levels. The estimated area under the receiver operating characteristic curve was 0.93, with a sensitivity of 96.2% and specificity of 82.9%.

CONCLUSIONS

We developed a risk score to predict CS in an at-risk population. This score may help to identify at-risk patients in non-endocrinological settings such as primary care, but external validation is warranted.

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

BACKGROUND

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

AIM

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Discovery of Cushing's Syndrome After Bariatric Surgery: Multicenter Series of 16 Patients

PURPOSE

The aim of this study is to demonstrate the importance of considering Cushing's syndrome (CS) as a potential etiology for weight gain and metabolic complications in patients undergoing bariatric surgery (BS).

DESIGN AND METHODS

This is a retrospective chart review case series of patients (n = 16) with CS from five tertiary care centers in the USA who had BS.

RESULTS

Median age at BS surgery was 35.5 years (median 2.5 years between BS and CS surgery). CS was not identified in 12 patients prior to BS. Four patients had CS surgery prior to BS, without recognition of recurrent or persistent CS until after BS. Median body mass index (BMI) values before BS, nadir after BS, prior to surgery for CS, and after surgery for CS were 47, 31, 38, and 35 kg/m(2), respectively. Prior to BS, 55 % of patients had hypertension and 55 % had diabetes mellitus. Only 17 % had resolution of hypertension or diabetes mellitus after BS.

CONCLUSION

CS may be under-recognized in patients undergoing BS. Testing for CS should be performed prior to BS in patients with features of CS and in post-operative BS patients with persistent hypertension, diabetes mellitus, or excessive weight regain. Studies should be conducted to determine the role of prospective testing for CS in subjects considering BS.

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.

Performance of the 1 mg dexamethasone suppression test in patients with severe obesity

OBJECTIVE

To analyze the performance of the 1 mg dexamethasone suppression test (DST) in patients with obesity. Special attention was paid to the influence of interfering medication on DST.

METHODS

In this prospective cohort study (Mannheim Obesity Study), patients with obesity were evaluated before bariatric surgery. For evaluation of hypercortisolism, a 1 mg dexamethasone-suppression test (DST) in all subjects was performed. Medication was assessed for possible interference.

RESULTS

Two hundred seventy-eight patients with a mean age of 42.3 years (68.8% women) and a mean BMI of 47.9 ± 8.4 kg/m(2) were screened. Insufficient suppression of cortisol after DST was found in 24 patients (8.6%). In two patients hypercortisolism was confirmed. The specificity for DST was calculated at 92.0%. Only CYP3A4 inducers (n = 22, 7.9%) and estrogen therapy (n = 17, 6.1%) were significantly associated with falsely elevated cortisol after DST. Regression analysis excluded any interrelation between DST and anthropometry.

CONCLUSIONS

Low prevalence of hypercortisolism (0.7 or <1.8%) was found. Specificity of DST in this cohort typically screened for hypercortisolism was 92.0% (≤ 50 nmol/L). DST should be avoided in patients taking CYP3A4 inducers or estrogen therapy, due to their significant interaction. In summary, the 1 mg DST is an adequate test for screening for hypercortisolism even in patients with extreme obesity.

Urinary glucocorticoid metabolites: biomarkers to classify adrenal incidentalomas?

OBJECTIVE

Total urinary cortisol metabolites represent cortisol production and metabolism. We hypothesized that to assay metabolites could add some information to the one provided by a sole cortisol assay.

DESIGN AND PATIENTS

We set up an inexpensive multiplex mass spectrometry assay to quantify cortisol metabolites. We investigated 43 patients with benign secreting (AT+) or silent (AT-) adrenal tumours compared to 48 lean (Nl) or 143 obese (Ob) subjects, and to 26 patients with a Cushing's disease (CD). The initial investigation included immunoreactive quantification of urinary free cortisol (UFC).

RESULTS

Cortisol metabolites were overexcreted in CD but not in Ob subjects. Nl and Ob were thus pooled in a control population (Ctl). Cortisol, tetrahydrocortisol (THF) and tetrahydrocortisone (THE) excretions were significantly increased in AT compared to Ctl subjects, whereas immunoreactive UFC was similar. A logistic regression retaining cortisol, THF, and α- and β-cortolone as significant analytes allowed the construction of a receiver-operating characteristics (ROC) curve significantly better than the curve generated by cortisol alone (area under the curve (AUC) 0·927 vs 0·729, respectively; P < 0·0001). More importantly, although there was no significant difference between Ctl vs AT- subjects for cortisol metabolites, a logistic regression retaining cortisol, allo-THF, and α- and β-cortolone as significant analytes generated a ROC curve performing significantly better than cortisol alone (AUC 0·910 vs 0·635, respectively; P < 0·0001).

CONCLUSION

Cortisol metabolite excretion is modified in AT, including AT-, patients even without modification of UFC. Clinical usefulness of these biomarkers has to be investigated in prospective studies following up patients with AT.

Is it worthwhile to screen patients with type 2 diabetes mellitus for subclinical Cushing's syndrome?

Variable prevalence of subclinical Cushing's syndrome (SCS) has been reported in patients with type 2 diabetes mellitus (T2DM), making the need for screening in this population uncertain. It is unknown if this variability is solely due to study-related methodological differences or a reflection of true differences in ethnic predisposition. The objective of this study is to explore the prevalence of SCS in Asian Indian patients with T2DM. In this prospective single center study conducted in a tertiary care referral center, 993 T2DM outpatients without any discriminatory clinical features (easy bruising, facial plethora, proximal muscle weakness, and/or striae) of hypercortisolism underwent an overnight 1 mg dexamethasone suppression test (ODST). ODST serum cortisol ≥1.8 μg/dl was considered positive, and those with positive results were subjected to 48 h, 2 mg/day low dose DST (LDDST). A stepwise evaluation for endogenous hypercortisolism was planned for patients with LDDST serum cortisol ≥1.8 μg/dl. Patients with positive ODST and negative LDDST were followed up clinically and re-evaluated a year later for the development of clinically evident Cushing's syndrome (CS). In this largest single center study reported to date, we found 37 out of 993 (3.72%) patients had ODST serum cortisol ≥1.8 μg/dl. None of them had LDDST cortisol ≥1.8 μg/dl, nor did they develop clinically evident CS over a follow-up period of 1 year. Specificity of ODST for screening of CS was 96.3% in our cohort. None of the T2DM outpatients in our cohort had SCS, hence cautioning against routine biochemical screening for SCS in this cohort. We suggest screening be based on clinical suspicion only.

Diagnostic use of facial image analysis software in endocrine and genetic disorders: review, current results and future perspectives

Cushing's syndrome (CS) and acromegaly are endocrine diseases that are currently diagnosed with a delay of several years from disease onset. Novel diagnostic approaches and increased awareness among physicians are needed. Face classification technology has recently been introduced as a promising diagnostic tool for CS and acromegaly in pilot studies. It has also been used to classify various genetic syndromes using regular facial photographs. The authors provide a basic explanation of the technology, review available literature regarding its use in a medical setting, and discuss possible future developments. The method the authors have employed in previous studies uses standardized frontal and profile facial photographs for classification. Image analysis is based on applying mathematical functions evaluating geometry and image texture to a grid of nodes semi-automatically placed on relevant facial structures, yielding a binary classification result. Ongoing research focuses on improving diagnostic algorithms of this method and bringing it closer to clinical use. Regarding future perspectives, the authors propose an online interface that facilitates submission of patient data for analysis and retrieval of results as a possible model for clinical application.

Residual manifestations of hypercortisolemia following surgical treatment in a patient with Cushing syndrome

Context

Cushing Syndrome is difficult to diagnose, and the comorbidities and persistent late effects of hypercortisolemia after treatment of the primary disease are challenging for the patient and the endocrinologist.

Objective

To report the case of a girl with obesity and hypertension, ultimately diagnosed with Cushing syndrome due to primary pigmented nodular adrenocortical disease. In this case, the complications of hypercortisolism persisted short term despite surgical intervention.

Patient

A 4 year old morbidly obese African-American girl with developmental delay presented with hypertensive emergency in the ER and 18-month history of progressive weight gain. Her previous history included premature adrenarche, hypertension, seizures and a random high cortisol with suppressed ACTH. She was subsequently stabilized, and a diagnostic work-up persistently demonstrated elevated cortisol and suppressed ACTH. An abdominal MRI showed bilateral adrenal multinodular disease, consistent with multinodular hyperplasia of the adrenal glands. Based on these findings the patient underwent a bilateral adrenalectomy, which confirmed primary pigmented nodular adrenocortical disease. The patient had a complicated, protracted post-operative course requiring adjustment of therapy for persistent hypertension. Two months after surgery, she was readmitted to the Emergency Department with hyperpyrexia and hypertension and succumbed to the complications of sepsis.

Conclusions and outcome

This case highlights the significant diagnostic and therapeutic challenges in treating children with Cushing syndrome. Resolution of the source of hypercortisolemia does not imply regression of hypertension or recovery of the immune system. Although the child underwent bilateral adrenalectomy, persistent consequences of prolonged severe hypercortisolism contributed to her death two months later.

Cushing's syndrome: epidemiology and developments in disease management

Cushing’s syndrome is a rare disorder resulting from prolonged exposure to excess glucocorticoids. Early diagnosis and treatment of Cushing’s syndrome is associated with a decrease in morbidity and mortality. Clinical presentation can be highly variable, and establishing the diagnosis can often be difficult. Surgery (resection of the pituitary or ectopic source of adrenocorticotropic hormone, or unilateral or bilateral adrenalectomy) remains the optimal treatment in all forms of Cushing’s syndrome, but may not always lead to remission. Medical therapy (steroidogenesis inhibitors, agents that decrease adrenocorticotropic hormone levels or glucocorticoid receptor antagonists) and pituitary radiotherapy may be needed as an adjunct. A multidisciplinary approach, long-term follow-up, and treatment modalities customized to each individual are essential for optimal control of hypercortisolemia and management of comorbidities.

Screening for Cushing's syndrome: is it worthwhile?

INTRODUCTION

Cushing's syndrome (CS) is a rare disease characterized by a collection of signs and symptoms, also common in the general population without elevated cortisol secretion. During the last years more patients with CS are identified earlier and with milder disease. Many of these patients are diagnosed during screening efforts performed for certain or isolated complaints like weight gain, diabetes mellitus (DM), hypertension, osteoporosis, elevated white blood cell counts and more.

METHODS

In this review article the most popular screening test performed in the studies cited was the 1-mg dexamethasone suppression test.

CONCLUSIONS

Cushing is not frequent enough to support the use of routine screening in patients with morbid obesity and type 2 DM. Also only 1% of hypertensive patients have secondary hypertension due to CS. However, screening should be considered in young patients with resistant DM and/or hypertension. Among patients with osteoporosis and vertebral fractures up to 5% were diagnosed with subclinical hypercortisolism; most of these had adrenal adenoma. Screening for CS is important in subjects with adrenal incidentaloma, and many studies show a high prevalence (~10%) of Cushing or subclinical CS in these patients.

Physiological basis for the etiology, diagnosis, and treatment of adrenal disorders: Cushing's syndrome, adrenal insufficiency, and congenital adrenal hyperplasia

The hypothalamic-pituitary-adrenal (HPA) axis is a classic neuroendocrine system. One of the best ways to understand the HPA axis is to appreciate its dynamics in the variety of diseases and syndromes that affect it. Excess glucocorticoid activity can be due to endogenous cortisol overproduction (spontaneous Cushing's syndrome) or exogenous glucocorticoid therapy (iatrogenic Cushing's syndrome). Endogenous Cushing's syndrome can be subdivided into ACTH-dependent and ACTH-independent, the latter of which is usually due to autonomous adrenal overproduction. The former can be due to a pituitary corticotroph tumor (usually benign) or ectopic ACTH production from tumors outside the pituitary; both of these tumor types overexpress the proopiomelanocortin gene. The converse of Cushing's syndrome is the lack of normal cortisol secretion and is usually due to adrenal destruction (primary adrenal insufficiency) or hypopituitarism (secondary adrenal insufficiency). Secondary adrenal insufficiency can also result from a rapid discontinuation of long-term, pharmacological glucocorticoid therapy because of HPA axis suppression and adrenal atrophy. Finally, mutations in the steroidogenic enzymes of the adrenal cortex can lead to congenital adrenal hyperplasia and an increase in precursor steroids, particularly androgens. When present in utero, this can lead to masculinization of a female fetus. An understanding of the dynamics of the HPA axis is necessary to master the diagnosis and differential diagnosis of pituitary-adrenal diseases. Furthermore, understanding the pathophysiology of the HPA axis gives great insight into its normal control.

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.

Routine Screening for Cushing's Syndrome Is Not Required in Patients Presenting with Obesity

Background. Cushing's syndrome (CS) is a relatively unusual condition that resembles many of the phenotypic features of obesity. Our aim was to evaluate the frequency of CS in obese patients. Materials and Methods. This study included 354 consecutive patients (87.9% female, age 37.8 ± 13.4 years) who presented with simple obesity. All the patients were evaluated for the clinical signs of CS. Lipid parameters, fasting glucose (FPG) and insulin, 75 gr oral glucose tolerance test, basal cortisol and ACTH were measured. 1 mg overnight DST was performed. Results. The mean weight of the patients was 102.4 ± 20.1 kg and BMI 40 ± 7.35 kg/m². 34.5% of the patients were hypertensive. 36.2% of the patients had central obesity, 72% dorsocervical fat accumulation, 28.8% abdominal striae and 23.2% acne. 49.4% of the women had hirsutism. 46.5% had prediabetes and 12.0% had type 2 diabetes, 72.6% had dyslipidemia. The mean cortisol and ACTH levels were as follows: 9.28 ± 3.53 μg/dL and 17.02 ± 10.43 pg/mL. Seven patients failed to suppress plasma cortisol to less than 1.8 μg/dL. Biochemical confirmation tests were performed in these patients and 2 of them were diagnosed glucocorticoid-secreting adrenal adenoma. Conclusions. Routine screening for CS in obese patients is not required.

A direct comparison of quality of life in obese and Cushing's syndrome patients

OBJECTIVE

Obese (OB) individuals and patients with Cushing's syndrome (CS) often have similar clinical presentations. While each group has reduced health-related quality of life (HRQL), it is not known whether the degree of impairment is different and might distinguish between them. The objective of this study was to compare HRQL in these two populations.

DESIGN

Cross-sectional study.

METHODS

Three hundred and twenty-seven OB patients (48.1±11.7 years; 72.5% women) with weight gain and at least two features of CS were recruited from an outpatient weight management clinic. Sixty-six untreated patients with CS (41.6±13.2 years; 78.8% women) presented to the NIH Clinical Center for evaluation. Subjects completed the SF-36 survey and a locally created symptom questionnaire.

RESULTS

After adjusting for symptom count, OB patients had a significantly higher (better HRQL) mean physical component summary (PCS) score than CS patients (44.9±0.6 vs 35.4±1.5, P<0.0001). However, the mean mental component summary (MCS) score was lower (worse HRQL) in the OB group (41.6±0.6 vs 50.7±1.6, P<0.0001). Symptom count showed significant correlations with PCS and MCS scores. BMI correlated with PCS (r=-0.29) in OB but not in CS patients. BMI was not associated with MCS in either group.

CONCLUSION

HRQL is significantly different between OB and CS patients. Surprisingly, after adjusting for symptom count, OB patients showed worse mental health scores than the CS population. Significant differences in HRQL and symptom count may suggest which OB patients should be screened for CS.

Metabolic complications of endogenous Cushing: patient selection for screening

Aims: this study evaluates the most common associations of symptoms and complications in patients with Cushing’s syndrome (CS) in order to choose a potential population to be screened for CS and estimates the diagnostic accuracy of first line screening tests (cortisol, ACTH) to differentiate ACTH-ectopic CS from Cushing’s disease. Materials and Methods: The clinical data of 259 patients with proven CS during 2001–2011 was analyzed. The clinical presentations of 197 patients (159 Cushing’s disease, 28 ACTH-ectopic CS and 10 cases of benign cortisol-secreting adrenal adenoma) were compared according to the cause of hypercortisolism. ROC-analysis was performed to estimate the diagnostic accuracy of the first line tests (cortisol, ACTH) to suggest ACTH-ectopic CS. A threshold for the test with the highest area under the curves was chosen based on the maximum sum of the sensitivity and specificity. Results: The most frequent complaints were related to fatigue, muscle weakness, weight gain and changes in appearance (facial plethora and fullness, striae). Among the complications of CS the most frequent were being overweight or obese (71%), hypertension (63%), dislipoproteinemia (41%), low traumatic fractures (43%) and steroid-induced diabetes (31%). In women, 16% were older than 50, in those who were younger amenorrhea was registered in 43%. The patients with ACTH-ectopic CS had higher rate of low traumatic fractures (p=0.04), increased serum late-night cortisol, 24 hours urinary free cortisol, morning and evening ACTH and lower levels of potassium (p0.01 for all parameters). Plasma late-night ACTH measurements showed the highest AUC (0,811 (95% CI 0,712–0,909)) to differentiate ACTH-ectopic CS from Cushing’s disease. A cut off value of 108.9 pg/ml for late-night ACTH yielded a sensitivity of 60,7% and a specificity of 79%. Conclusions: patients with a coexistence of obesity, muscle weakness, fatigue, some components of metabolic syndrome and especially low traumatic fractures should be screened for CS. High plasma late night ACTH values in patients with proven CS value suggest ACTH-ectopic syndrome.

Routine screening for Cushing's syndrome is not required in patients presenting with hirsutism

CONTEXT

Prevalence of Cushing's syndrome (CS) in patients presenting with hirsutism is not well known.

OBJECTIVE

Screening of CS in patients with hirsutism.

SETTING

Referral hospital.

PATIENTS AND OTHER PARTICIPANTS

This study was carried out on 105 patients who were admitted to the Endocrinology Department with the complaint of hirsutism.

INTERVENTION

All the patients were evaluated with low-dose dexamethasone suppression test (LDDST) for CS.

MAIN OUTCOME MEASURE

Response to LDDST in patients presenting with hirsutism.

RESULTS

All the patients had suppressed cortisol levels following low-dose dexamethasone administration excluding CS. The etiology of hirsutism was polycystic ovary syndrome in 79%, idiopathic hirsutism in 13%, idiopathic hyperandrogenemia in 6%, and nonclassical congenital hyperplasia in 2% of the patients.

CONCLUSION

Routine screening for CS in patients with a referral diagnosis of hirsutism is not required. For the time being, diagnostic tests for CS in hirsute patients should be limited to patients who have accompanying clinical stigmata of hypercortisolism.

Cortisol, obesity, and the metabolic syndrome: a cross-sectional study of obese subjects and review of the literature

OBJECTIVE

Circulating cortisol and psychosocial stress may contribute to the pathogenesis of obesity and metabolic syndrome (MS). To evaluate these relationships, a cross-sectional study of 369 overweight and obese subjects and 60 healthy volunteers was performed and reviewed the previous literature.

DESIGN AND METHODS

Overweight and obese subjects had at least two other features of Cushing's syndrome. They underwent measurements representing cortisol dynamics (24 h urine cortisol excretion (UFC), bedtime salivary cortisol, 1 mg dexamethasone suppression test) and metabolic parameters (BMI, blood pressure (BP); fasting serum triglycerides, HDL, insulin, and glucose). Subjects also completed the Perceived Stress Scale (PSS). UFC, salivary cortisol, and weight from 60 healthy volunteers were analyzed.

RESULTS

No subject had Cushing's syndrome. UFC and dexamethasone responses were not associated with BMI or weight. However, salivary cortisol showed a trend to increase as BMI increased (P < 0.0001), and correlated with waist circumference (WC) in men (rs = 0.28, P = 0.02) and systolic BP in women (rs = 0.24, P = 0.0008). Post-dexamethasone cortisol levels were weak to moderately correlated with fasting insulin (rs = -0.31, P = 0.01) and HOMA-IR (rs = -0.31, P = 0.01) in men and systolic (rs = 0.18, P = 0.02) and diastolic BP (rs = 0.20, P = 0.009) in women. PSS results were higher in obese subjects than controls, but were not associated with cortisol or metabolic parameters. As expected, WC correlated with fasting insulin, HOMA-IR, and systolic BP (adjusted for BMI and gender; P < 0.01). Literature showed inconsistent relationships between cortisol and metabolic parameters.

CONCLUSION

Taken together, these data do not support a strong relationship between systemic cortisol or stress and obesity or MS.

Prevalence and associated factors of subclinical hypercortisolism in patients with resistant hypertension

BACKGROUND

Subclinical hypercortisolism is a secondary cause of hypertension that had never been evaluated in resistant hypertensive patients, a subgroup of general hypertensive individuals with an expected high prevalence of secondary hypertension.

METHODS

Four hundred and twenty-three patients with resistant hypertension and ages up to 80 years were screened for the presence of subclinical hypercortisolism by morning serum cortisol after a midnight 1 mg dexamethasone suppression test (DST). Those with morning cortisol of at least 50  nmol/l had hypercortisolism confirmed by two salivary cortisol of at least 3.6  nmol/l collected at 2300  h. Statistical analysis included bivariate tests between those with positive and negative screening test and with and without confirmed hypercortisolism, and logistic regressions to assess their independent correlates.

RESULTS

One hundred and twelve patients (prevalence 26.5%, 95% confidence interval 22.0-31.9%) had the screening test positive for suspected hypercortisolism. None had overt Cushing syndrome. Patients with positive screening were older, more frequently males, had higher prevalences of diabetes and target-organ damage and higher nighttime SBPs than patients with normal screening test results. Thirty-four patients (total prevalence 8.0%, 95% confidence interval: 5.7-11.2%) had confirmed hypercortisolism. Independent correlates of a positive DST were older age (P = 0.007), male sex (P = 0.012) and presence of cardiovascular diseases (P = 0.002) and chronic kidney disease (P = 0.016). Correlates of confirmed subclinical hypercortisolism were older age (P = 0.020), diabetes (P = 0.06) and a nondipping pattern on ambulatory blood pressure monitoring (P = 0.04).

CONCLUSION

Patients with resistant hypertension had a relatively high prevalence of subclinical hypercortisolism, and its presence is associated with several markers of worse cardiovascular prognosis.

The hypothalamic-pituitary-adrenal axis and sex hormones in chronic stress and obesity: pathophysiological and clinical aspects

Obesity, particularly the abdominal phenotype, has been ascribed to an individual maladaptation to chronic environmental stress exposure mediated by a dysregulation of related neuroendocrine axes. Alterations in the control and action of the hypothalamic-pituitary-adrenal axis play a major role in this context, with the participation of the sympathetic nervous system. The ability to adapt to chronic stress may differ according to sex, with specific pathophysiological events leading to the development of stress-related chronic diseases. This seems to be influenced by the regulatory effects of sex hormones, particularly androgens. Stress may also disrupt the control of feeding, with some differences according to sex. Finally, the amount of experimental data in both animals and humans may help to shed more light on specific phenotypes of obesity, strictly related to the chronic exposure to stress. This challenge may potentially imply a different pathophysiological perspective and, possibly, a specific treatment.