Is subclinical Cushing's syndrome an entity or a statistical fallout from diagnostic testing? Consensus surrounding the diagnosis is required before optimal treatment can be defined

Frequently asked questions and answers (if any) in patients with adrenal incidentaloma

PURPOSE

Adrenal incidentalomas (AIs) are incidentally discovered adrenal masses, during an imaging study undertaken for other reasons than the suspicion of adrenal disease. Their management is not a minor concern for patients and health-care related costs, since their increasing prevalence in the aging population. The exclusion of malignancy is the first question to attempt, then a careful evaluation of adrenal hormones is suggested. Surgery should be considered in case of overt secretion (primary aldosteronism, adrenal Cushing's Syndrome or pheochromocytoma), however the management of subclinical secretion is still a matter of debate.

METHODS

The aim of the present narrative review is to offer a practical guidance regarding the management of AI, by providing evidence-based answers to frequently asked questions.

CONCLUSION

The clinical experience is of utmost importance: a personalized diagnostic-therapeutic approach, based upon multidisciplinary discussion, is suggested.

Approach to the Patient with an Incidental Adrenal Mass

Adrenal masses are frequently incidentally identified from cross-sectional imaging studies, which are performed for other reasons. The intensity of the approach to the patient with such a mass is tailored to the clinical situation, ranging from a quick evaluation to a detailed work-up. In all cases, the three components of the evaluation are clinical assessment, review of the images, and biochemical testing with the goal of ruling out malignancy and identifying hormonally active lesions. This article incorporates recent information to produce a logical, systematic assessment of these patients with risk stratification and proportionate follow-up.

Cardiovascular and metabolic risk factors in patients with subclinical Cushing

PURPOSE

Adrenal incidentalomas (AI) are discovered after work-up unrelated to adrenal gland diseases; up to 30% of AI show subclinical endogenous cortisol excess (SH), frequently associated to hypertension, obesity, metabolic disorders and increased incidence of cardiovascular events (CVEs).

METHODS

We analysed 628 AI patients divided into two groups: 471 non-functional adrenal adenoma (NFA) and 157 SH. All patients underwent complete examinations, 24-h ambulatory blood pressure monitoring, biohumoral parameters and vascular damage markers, such as c-IMT and ankle brachial index. After long-term follow-up, we registered newly onset of CVEs such as myocardial infarction (MI), percutaneous stenting and surgical bypass (PTA/CABG), stroke, overall/cardiovascular mortality. Moreover, SH patients underwent to surgical (SSH) or pharmacological treatment (MSH).

RESULTS

SH patients showed higher prevalence of metabolic syndrome, diabetes mellitus, and previous CVEs respect NFA at baseline. After follow-up MSH group showed higher recurrence of major CV events compared with NFA and SSH (RR 2.27 MSH vs NFA for MI; RR 2.30 MSH vs NFA for PTA/CABG; RR 2.41 MSH vs NFA for stroke). In SSH there was a significant reduction of the number of antihypertensive medications needed to reach target blood pressure levels (2.3 ± 1.0 to 1.5 ± 0.4 drugs). None differences were found in SH patients, distinguished in relation to cortisol plasma levels after dexamethasone suppression test (1.8-5 µg/dL, above 5 µg/dL).

CONCLUSIONS

SH is linked to relevant cardiovascular and metabolic alterations, leading to worsen clinical outcomes. In eligible patients, adrenalectomy is valid and safe option to treat SH, reducing cardiometabolic abnormalities.

Primary aldosteronism concurrent with subclinical Cushing's syndrome: a case report and review of the literature

Background

The prevalence of primary aldosteronism concurrent with subclinical Cushing’s syndrome was higher than previously thought. Through analyzing a rare clinical case, we summarized the diagnosis and management of primary aldosteronism with subclinical Cushing’s syndrome.

Case presentation

A 54-year-old Chinese man of Han nationality was diagnosed as having primary aldosteronism with subclinical Cushing’s syndrome. An abdominal computed tomography scan revealed a mass in his left adrenal gland and a mass in his right adrenal gland. After finishing sequential adrenal venous sampling without adrenocorticotropic hormone, the result reminded us that the left and right nodules were responsible for hypercortisolism and aldosterone hypersecretion, respectively. Right and left adrenalectomy were performed successively. The pathological diagnosis was adrenocortical adenoma for both. Histological findings revealed that the right one had positive immunostaining for CYP11B2 and the left one had positive immunostaining for CYP11B1. The immunohistochemistry result helped us to confirm the diagnosis. Somatic KCNJ5 mutation (Leu168Arg) was found in the right tumor; there was no KCNJ5 mutation in the left adrenal tumor.

Conclusions

We suggest that patients with primary aldosteronism should have a low-dose overnight dexamethasone suppression test to screen for hypercortisolism. It can help avoid misdiagnoses and contribute to proper understanding of the adrenal vein sampling result. Making sure of the nidus of aldosterone and cortisol secretion is crucial for the therapy of patients with primary aldosteronism and subclinical Cushing’s syndrome.

Plasma Steroid Profiles in Subclinical Compared With Overt Adrenal Cushing Syndrome

CONTEXT

Diagnosis of subclinical adrenal hypercortisolism is based on several tests of the hypothalamic-pituitary-adrenal axis to establish mild alterations of cortisol secretion and dysregulated cortisol physiology.

OBJECTIVE

We assessed whether plasma steroid profiles might assist diagnosis of subclinical Cushing syndrome (SC).

DESIGN

Retrospective cross-sectional study.

SETTING

Two tertiary medical centers.

PATIENTS

Of 208 patients tested for hypercortisolism, disease was excluded in 152 and confirmed in 21 with overt adrenal Cushing syndrome (AC) compared to 35 with SC. Another 277 age- and sex-matched hypertensive and normotensive volunteers were included for reference.

MAIN OUTCOME MEASURES

A panel of 15 plasma steroids was measured by mass spectrometry, with classification by discriminant analysis.

RESULTS

Patients with SC had lower plasma concentrations of dehydroepiandrosterone and dehydroepiandrosterone-sulfate than subjects without SC (P < 0.05). The largest increases (P < 0.001) in plasma steroids among patients with SC were observed for 11-deoxycortisol and 11-deoxycorticosterone. Nevertheless, concentrations of 11-deoxycorticosterone, 11-deoxycortisol, and pregnenolone in patients with AC were higher (P < 0.05) than in those with SC. Patients with SC or AC could be distinguished from subjects without disease using this combination of steroids as precisely as with use of measurements of serum cortisol after administration of dexamethasone. The steroid combination provided superior diagnostic performance compared with each of the other routine biochemical tests.

CONCLUSION

Distinct plasma steroid profiles in patients with SC may provide a simple and reliable screening method for establishing the diagnosis.

Adrenalectomy was recommended for patients with subclinical Cushing's syndrome due to adrenal incidentaloma

OBJECTIVE

To assess whether adrenalectomy may improve biochemical and metabolic impairment for patients with subclinical Cushing syndrome (SCS) due to adrenal incidentaloma (AI) compared with conservative management.

METHODS

A total of 87 patients with SCS due to AI in Peking Union Medical College Hospital between September 2011 and January 2016 have been treated. Forty-eight patients underwent laparoscopic adrenalectomy (operative group), whereas 39 were managed conservatively (control group).

RESULTS

The duration of follow-up was 32.5 ± 10.6 months in operative group, and 30.1 ± 13.1 months in control group, respectively. In the operative group, laboratory corticosteroid parameters normalized in all patients but not in the control group. In the operative group, BP of hypertensive patients improved or normalized (22 of 48); to the contrary, in the control group, cure or improvement was never achieved among the patients with hypertension, whereas a worsening was observed in 5 patients (P= 0.004). No significant difference was found in glycemic control and blood lipid change between the two groups. However, a decrease in triglyceridaemia and HBA1c was found in operative group compared with the control group (P= 0.011 and P= 0.017, respectively). Substitutive corticosteroid treatment was administered in 3 patients due to postoperative adrenal insufficiency during hospital stay, and the duration of treatment was 9 weeks, 10 weeks and 12 weeks, respectively.

CONCLUSIONS

Laparoscopic adrenalectomy should be performed for patients with SCS due to AI.

Do the diagnostic criteria for subclinical hypercortisolism exist?

"Subclinical hypercortisolism" (SH) refers to a condition associated with a mild chronic increase in cortisol secretion. By definition, patients with SH do not exhibit specific symptoms of overt Cushing's syndrome (such as purple striae, easy bruising, proximal muscle weakness), SH has been preferred to "subclinical Cushing's syndrome", a semantic ambiguity since Cushing's syndrome is, by definition, a set of symptoms; and to the term "preclinical Cushing syndrome" because the progression toward overt clinical hypercortisolism is very rare. However, SH still is misnomer as a number of studies suggest that this condition may induce long-term non-specific adverse conditions related to the mild cortisol excess (i.e. diabetes, hypertension, obesity, and osteoporosis). Various attempts have been made to define SH that remains a matter of controversies and uncertainties.

Six controversial issues on subclinical Cushing's syndrome

Subclinical Cushing's syndrome is a condition of hypercortisolism in the absence of signs specific of overt cortisol excess, and it is associated with an increased risk of diabetes, hypertension, fragility fractures, cardiovascular events and mortality. The subclinical Cushing's syndrome is not rare, being estimated to be between 0.2-2 % in the adult population. Despite the huge number of studies that have been published in the recent years, several issues remain controversial for the subclinical Cushing's syndrome screening, diagnosis and treatment. The Altogether to Beat Cushing's syndrome Group was founded in 2012 for bringing together the leading Italian experts in the hypercortisolism-related diseases. This document represents the Altogether to Beat Cushing's syndrome viewpoint regarding the following controversial issues on Subclinical Cushing's syndrome (SCS): (1) Who has to be screened for subclinical Cushing's syndrome? (2) How to screen the populations at risk? (3) How to diagnose subclinical Cushing's syndrome in patients with an adrenal incidentaloma? (4) Which consequence of subclinical Cushing's syndrome has to be searched for? (5) How to address the therapy of choice in AI patients with subclinical Cushing's syndrome? (6) How to follow-up adrenal incidentaloma patients with subclinical Cushing's syndrome surgically or conservatively treated? Notwithstanding the fact that most studies that faced these points may have several biases (e.g., retrospective design, small sample size, different criteria for the subclinical Cushing's syndrome diagnosis), we believe that the literature evidence is sufficient to affirm that the subclinical Cushing's syndrome condition is not harmless and that the currently available diagnostic tools are reliable for identifying the majority of individuals with subclinical Cushing's syndrome.

THERAPY OF ENDOCRINE DISEASE: Improvement of cardiovascular risk factors after adrenalectomy in patients with adrenal tumors and subclinical Cushing's syndrome: a systematic review and meta-analysis

OBJECTIVE

Beneficial effects of adrenalectomy on cardiovascular risk factors in patients with subclinical Cushing's syndrome (SCS) are uncertain. We sought to conduct a systematic review and meta-analysis with the following objectives: (i) determine the effect of adrenalectomy compared with conservative management on cardiovascular risk factors in patients with SCS and (ii) compare the effect of adrenalectomy on cardiovascular risk factors in patients with SCS vs those with a nonfunctioning (NF) adrenal tumor.

METHODS

MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE and Cochrane Central Register of Controlled Trial were searched on 17 November 2015. Reviewers extracted data and assessed methodological quality in duplicate.

RESULTS

We included 26 studies reporting on 584 patients with SCS and 457 patients with NF adrenal tumors. Studies used different definitions of SCS. Patients with SCS undergoing adrenalectomy demonstrated an overall improvement in cardiovascular risk factors (61% for hypertension, 52% for diabetes mellitus, 45% for obesity and 24% for dyslipidemia). When compared with conservative management, patients with SCS undergoing adrenalectomy experienced improvement in hypertension (RR 11, 95% CI: 4.3-27.8) and diabetes mellitus (RR 3.9, 95% CI: 1.5-9.9), but not dyslipidemia (RR 2.6, 95% CI: 0.97-7.2) or obesity (RR 3.4, 95% CI: 0.95-12). Patients with NF adrenal tumors experienced improvement in hypertension (21/54 patients); however, insufficient data exist for comparison to patients with SCS.

CONCLUSIONS

Available low-to-moderate-quality evidence from heterogeneous studies suggests a beneficial effect of adrenalectomy on cardiovascular risk factors in patients with SCS overall and compared with conservative management.

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.

Serum Adiponectin Level as a Predictor of Subclinical Cushing's Syndrome in Patients with Adrenal Incidentaloma

Subclinical Cushing's syndrome (SCS) is a condition of slight but chronic cortisol excess in patients with adrenal incidentaloma (AI) without typical signs and symptoms of Cushing's syndrome. Adiponectin has potent roles in modulating energy balance and metabolic homeostasis and acts in opposition to glucocorticoids. This study aimed to evaluate adiponectin level in SCS and nonfunctional AI (NAI) patients and its relation with metabolic parameters. Patients with AI (n = 40) and metabolically healthy controls (n = 30) were included. In AI patients and controls, detailed medical history assessment, physical examinations, anthropometric measurements, and laboratory measurements were performed. Age, body mass index, waist circumference, and lipid profiles were significantly higher and waist-to-hip ratio and adiponectin level were significantly lower in the AI patients than in the controls. The midnight cortisol and urinary free cortisol levels were significantly higher in the SCS patients (n = 8) than in the NAI patients (n = 32). Adiponectin level of the SCS group was significantly lower than those of the NAI and control groups. The sensitivity and specificity for an adiponectin level of ≤13.00 ng/mL in predicting the presence of SCS were 87.5% and 77.4%, respectively. In conclusion, adiponectin is valuable in predicting the presence of SCS in AI patients.

Adrenal mild hypercortisolism

Adrenal incidentalomas have become detected more often as the use of abdominal imaging has increased. Up to one-third of these may be secreting low levels of cortisol, known as mild hypercortisolism or subclinical Cushing syndrome. These low levels of cortisol have been found to be associated with an increased in the metabolic syndrome, osteoporosis, cardiovascular events, and mortality. This article discusses in detail the epidemiology, diagnosis, clinical associations, and treatment options of mild hypercortisolism.

Subclinical hypercortisolism in adrenal incidentaloma

PURPOSE OF REVIEW

The article aims to update the reader on current developments in the area of adrenal incidentaloma complicated by subclinical hypercortisolism. We will discuss different diagnostic strategies and complications associated with this disease, and address the conflicting opinions related to the treatment of these patients.

RECENT FINDINGS

Depending on diagnostic criteria used, between 30 and 50% of patients with adrenocortical incidentaloma have biochemical hypercortisolism, but lack classical external features of Cushing's syndrome. The challenge facing the clinician is that in the sixth and seventh decade of life hypertension, diabetes, osteoporosis and obesity are common and establishing whether these are directly related to the low-grade excess cortisol secretion in a given individual is not straightforward. Nevertheless, this subclinical hypercortisolism has been found to be associated with multiple cardiovascular risk factors, an increased predisposition to cardiovascular events and a higher mortality rate. The dilemma is that it is not established whether surgical excision of the adrenal adenoma in a given individual will improve these complications, and data demonstrate that surgical studies are conflicting.

SUMMARY

Subclinical hypercortisolism is associated with multiple complications and definite guidelines for diagnosis are necessary. Prospective, randomized controlled studies are needed to ascertain whether medical or surgical interventions are justified, and in which patients.

Update on subclinical Cushing's syndrome

PURPOSE OF REVIEW

The present review summarizes recent findings in the diagnosis and treatment of subclinical Cushing's syndrome, a condition of subtle cortisol dysregulation with a spectrum of clinical and biochemical abnormalities.

RECENT FINDINGS

The diagnosis of subclinical Cushing's syndrome is suggested by abnormal suppression to dexamethasone in a patient with an adrenal mass. The natural history of this disorder includes progression in a minority of cases, and increased cardiovascular disease in patients with more severe and progressive disease, much as is found in overt Cushing's syndrome. In patients with an abnormal response to dexamethasone, additional biochemical and metabolic features increase confidence in the ability of adrenalectomy to reverse clinical abnormalities. In addition, bilateral masses and larger masses are more likely to be associated with hypercortisolism.

SUMMARY

We review the recent literature on subclinical cortisol secretion and suggest that additional studies are needed to define optimal diagnostic and therapeutic approaches.

Pathophysiology, diagnosis, and treatment of mineralocorticoid disorders

The renin-angiotensin-aldosterone system (RAAS) is a major regulator of blood pressure control, fluid, and electrolyte balance in humans. Chronic activation of mineralocorticoid production leads to dysregulation of the cardiovascular system and to hypertension. The key mineralocorticoid is aldosterone. Hyperaldosteronism causes sodium and fluid retention in the kidney. Combined with the actions of angiotensin II, chronic elevation in aldosterone leads to detrimental effects in the vasculature, heart, and brain. The adverse effects of excess aldosterone are heavily dependent on increased dietary salt intake as has been demonstrated in animal models and in humans. Hypertension develops due to complex genetic influences combined with environmental factors. In the last two decades, primary aldosteronism has been found to occur in 5% to 13% of subjects with hypertension. In addition, patients with hyperaldosteronism have more end organ manifestations such as left ventricular hypertrophy and have significant cardiovascular complications including higher rates of heart failure and atrial fibrillation compared to similarly matched patients with essential hypertension. The pathophysiology, diagnosis, and treatment of primary aldosteronism will be extensively reviewed. There are many pitfalls in the diagnosis and confirmation of the disorder that will be discussed. Other rare forms of hyper- and hypo-aldosteronism and unusual disorders of hypertension will also be reviewed in this article.

Systematic review of surgical treatment of subclinical Cushing's syndrome

BACKGROUND

Subclinical Cushing's syndrome (SCS) is a condition of biochemical cortisol excess without the classical clinical features of overt hypercortisolism; it may be associated with some consequences of metabolic syndrome. The most appropriate treatment remains controversial. This study aimed to assess the outcomes of adrenalectomy for SCS.

METHODS

A systematic review was performed. MEDLINE, Embase and Cochrane Databases (1980-2013) were searched for studies reporting the outcomes of unilateral adrenalectomy with respect to hypertension, diabetes, dyslipidaemia, obesity and osteoporosis in patients with SCS. Studies with a questionable diagnosis of SCS, bilateral adrenal involvement and insufficient data were excluded.

RESULTS

Of the 105 papers screened, seven were selected; there were six retrospective studies and one randomized clinical trial, including 230 patients. Data analysis was limited by heterogeneity in definition of SCS and endpoints. Hypercortisolism was cured in all operated patients. Laparoscopy was the preferred approach, with a morbidity rate of 0·8 per cent. A beneficial effect of surgery on blood pressure, glucometabolic control and obesity was evident in all studies, with cure or improvement in 72, 46 and 39 per cent of patients respectively, compared with conservative management. The results for lipid metabolism were equivocal, because of a decrease in triglyceridaemia but discordant effects on cholesterol metabolism among the different studies. No beneficial effects on osteoporosis were found.

CONCLUSION

Laparoscopic adrenalectomy seems to be beneficial in reversing several metabolic effects of hypercortisolism, with a low morbidity rate. However, the heterogeneity and low quality of the available studies preclude definitive recommendations.

Cortisol as a marker for increased mortality in patients with incidental adrenocortical adenomas

CONTEXT

Incidental benign adrenocortical adenomas, adrenal incidentalomas are found in 4.5% of abdominal computed tomography scans, with the incidence increasing to 10% in patients older than 70 years of age. These incidentalomas frequently show evidence of excess cortisol secretion but without overt Cushing's syndrome. The mortality rate is increased in Cushing's syndrome.

OBJECTIVE

This study sought to investigate whether patients with adrenal incidentalomas have an increased mortality.

DESIGN

This was a retrospective, longitudinal cohort study.

SETTING

The study was carried out in an Endocrine Investigation Unit in a University Teaching Hospital.

PATIENTS

Two hundred seventy-two consecutive patients with an incidental adrenal mass underwent a dedicated diagnostic protocol, which included dexamethasone testing for hypercortisolism between 2005 and 2013. Overall survival was assessed in 206 patients with a benign, adrenocortical adenoma.

MAIN OUTCOME MEASURES

Survival analysis was carried out by using Kaplan-Meier curves and the effect of dexamethasone cortisol estimated by Cox-regression analysis. Cause-specific mortality was ascertained from death certificates and compared with local and national data.

RESULTS

Eighteen of 206 patients died and the mean time (SD) from diagnosis to death was 3.2 (1.7) years. Seventeen of 18 patients who died had a post dexamethasone cortisol >1.8 μg/dL and there was a significant decrease in survival rate with increasing dexamethasone cortisol levels (P = .001). Compared with the <1.8 μg/dL group, the hazard ratio (95% confidence interval) for the 1.8-5 μg/dL group was 12.0 (1.6-92.6) whereas that of the >5 μg/dL group was 22.0 (2.6-188.3). Fifty percent and 33% of deaths were secondary to circulatory or respiratory/infective causes, respectively.

CONCLUSIONS

PATIENTS with adrenal incidentalomas and a post-dexamethasone serum cortisol >1.8 μg/dL have increased mortality, mainly related to cardiovascular disease and infection.

Cushing's disease, pseudo-Cushing states and the dexamethasone test: a historical and critical review

The dexamethasone (DXM) test has been widely used for diagnosing Cushing's disease (CD). The purpose of this paper is to review its diagnostic merit based on calculation of data extracted from earlier publications. Studies presenting individual values for patients with CD and normal subjects were identified through PubMed searches and references in pertinent studies. Calculation of the retrieved data demonstrated huge variation in the relative suppressibility, negative suppression being common. Furthermore, in almost each study retrieved, the pre and post DXM values were closely correlated. Finally, the generally accepted view that DXM causes less suppression in Cushing's disease than in euadrenal controls appears unfounded. A central issue in the definition of so-called "pseudo-Cushing's states" is failure to suppress cortisol secretion with DXM. From analysis of the literature it appears quite possible that this does not reflect a specific endocrine deficit, but a physiological "stress" reaction. The above issues question the diagnostic value of the test, in particular in clinically and biochemically borderline cases.

Patients with apparently nonfunctioning adrenal incidentalomas may be at increased cardiovascular risk due to excessive cortisol secretion

CONTEXT

Although adrenal incidentalomas (AIs) are associated with a high prevalence of cardiovascular risk (CVR) factors, it is not clear whether patients with nonfunctioning AI (NFAI) have increased CVR.

OBJECTIVE

Our objective was to investigate CVR in patients with NFAI.

DESIGN AND SETTING

This case-control study was performed in a tertiary general hospital.

SUBJECTS

SUBJECTS included 60 normotensive euglycemic patients with AI and 32 healthy controls (C) with normal adrenal imaging.

MAIN OUTCOME MEASURES

All participants underwent adrenal imaging, biochemical and hormonal evaluation, and the following investigations: 1) measurement of carotid intima-media thickness (IMT) and flow-mediated dilatation, 2) 2-hour 75-gram oral glucose tolerance test and calculation of insulin resistance indices (homeostasis model assessment, quantitative insulin sensitivity check, and Matsuda indices), 3) iv ACTH stimulation test, 4) low-dose dexamethasone suppression test, and 5) NaCl (0.9%) post-dexamethasone saline infusion test.

RESULTS

Based on cutoffs obtained from controls, autonomous cortisol secretion was documented in 26 patients (cortisol-secreting AI [CSAI] group), whereas 34 exhibited adequate cortisol and aldosterone suppression (NFAI group). IMT measurements were higher and flow-mediated vasodilatation was lower in the CSAI group compared with both NFAI and C and in the NFAI group compared with C. The homeostasis model assessment index was higher and quantitative insulin sensitivity check index and Matsuda indices were lower in the CSAI and NFAI groups compared with C as well as in CSAI compared with the NFAI group. The area under the curve for cortisol after ACTH stimulation was higher in the CSAI group compared with the NFAI group and C and in the NFAI group compared with C. In the CSAI group, IMT correlated with cortisol, urinary free cortisol, and cortisol after a low-dose dexamethasone suppression test, whereas in the NFAI group, IMT correlated with area under the curve for cortisol after ACTH stimulation and urinary free cortisol.

CONCLUSIONS

Patients with CSAI without hypertension, diabetes, and/or dyslipidemia exhibit adverse metabolic and CVR factors. In addition, NFAIs are apparently associated with increased insulin resistance and endothelial dysfunction that correlate with subtle but not autonomous cortisol excess.

Visceral fat accumulation and postdexamethasone serum cortisol levels in patients with adrenal incidentaloma

OBJECTIVE

Visceral fat is a significant cardiovascular risk factor. Because visceral fat has not been measured systematically in patients with adrenal incidentalomas, we have tested the hypothesis that visceral fat volume may be associated with cutoffs for serum cortisol levels post dexamethasone.

DESIGN

This was a retrospective, cross-sectional study.

SETTING

The study was conducted at the Endocrine Investigation Unit, University Teaching Hospital.

PARTICIPANTS

Seventy-three women and 52 men diagnosed with adrenal incidentalomas and 9 patients with overt Cushing's syndrome participated in this study.

MAIN OUTCOME MEASURES

The following was measured for serum cortisol level after dexamethasone suppression and visceral fat ratios: visceral-subcutaneous (V:S) and visceral-total volume (V:TV) measured by computed tomography.

RESULTS

Sixty-eight patients with a postdexamethasone serum cortisol greater than 1.8 μg/dL (50 nmol/L) showed a significantly higher mean V:S and V:TV fat ratio compared with those whose serum cortisol was less than 1.8 μg/dL: women, lnV:S, -0.45 vs -0.69 [mean difference 0.24 (95% confidence interval [CI] 0.08-0.41); P = .004] and V:TV, 0.39 vs 0.34 [mean difference 0.05 (95% CI 0.02-0.09); P = .004]; men, lnV:S, 0.64 vs 0.29 [mean difference 0.35 95% CI 0.08-0.63); P = .01] and V:TV, 0.65 vs 0.57 [mean difference 0.08 (95% CI 0.02-0.14); P = .02]. By ANOVA and post hoc analysis (Fisher's least significant differences), there was no difference in fat ratios between the postdexamethasone serum cortisol groups [1.8-2.9 μg/dL (50-82 nmol/L), 3.0-5.0 μg/dL (83-137 nmol/L), > 5.0 μg/dL (>138 nmol/L) and Cushing's syndrome (mean V:TV: 0.38, 0.40, 0.40, 0.41, respectively)], but they all differed significantly from the less than the 1.8-μg/dL group (V:TV: 0.34, P = .03).

CONCLUSION

Visceral fat is increased in patients with adrenal incidentalomas and a postdexamethasone serum cortisol of greater than 1.8 μg/dL and is similar to that found in patients with overt Cushing's syndrome.

Mifepristone reduces insulin resistance in patient volunteers with adrenal incidentalomas that secrete low levels of cortisol: a pilot study

Background

Incidental adrenal masses are commonly detected during imaging for other pathologies. 10% of the elderly population has an ‘adrenal incidentaloma’, up to 20% of these show low-grade autonomous cortisol secretion and 60% of patients with autonomous cortisol secretion have insulin resistance. Cortisol excess is known to cause insulin resistance, an independent cardiovascular risk marker, however in patients with adrenal incidentalomas it is unknown whether their insulin resistance is secondary to the excess cortisol and therefore potentially reversible. In a proof of concept study we examined the short-term effects of glucocorticoid receptor (GR) antagonism in patients with an adrenal incidentaloma to determine whether their insulin resistance was reversible.

Methodology/Principal Findings

In a prospective open-label pilot study, six individuals with adrenal incidentalomas and autonomous cortisol secretion were treated with mifepristone (a GR antagonist) 200 mg twice daily and studied for 4 weeks on a Clinical Research Facility. Insulin resistance at four weeks was assessed by insulin resistance indices, lnHOMA-IR and lnMatsuda, and AUC insulin during a 2-hour glucose tolerance test. Biochemical evidence of GR blockade was shown in all individuals and across the group there was a significant reduction in insulin resistance: lnHOMA-IR (1.0vs0.6; p = 0.03), lnHOMA-%beta (4.8vs4.3; p = 0.03) and lnMatsuda (1.2vs1.6; p = 0.03). Five out of six individuals showed a reduction in insulin AUC >7237 pmol/l.min, and in two patients this showed a clinically significant cardiovascular benefit (as defined by the Helsinki heart study).

Conclusions

Short-term GR antagonism is sufficient to reduce insulin resistance in some individuals with adrenal incidentalomas and mild cortisol excess. Further assessment is required to assess if the responses may be used to stratify therapy as adrenal incidentalomas may be a common remediable cause of increased cardiovascular risk.

Trial Registration

ClinicalTrials.gov NCT00721201

The role of salivary cortisol measured by liquid chromatography-tandem mass spectrometry in the diagnosis of subclinical hypercortisolism

OBJECTIVE

The use of late-night salivary cortisol (LNSalC) for diagnosing subclinical hypercortisolism (SH) is debated. No data are available regarding the role of LNSalC as measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in SH diagnosis. The aim of this study was to evaluate the diagnostic accuracy of LNSalC measured by LC-MS/MS in SH.

DESIGN

Cross-sectional prospective study of outpatients.

METHODS

In 70 consecutive patients with adrenal incidentalomas (AI), without signs and symptoms of hypercortisolism, we diagnosed SH in the presence of at least two of the following: cortisol after 1 mg overnight dexamethasone suppression test (1  mg DST) >83  nmol/l, 24-h urinary free cortisol (UFC) >193  nmol/24  h, and morning ACTH <2.2  pmol/l. The LNSalC levels by LC-MS/MS at 2300  h (normal values <2.8  nmol/l) and the presence of hypertension, type 2 diabetes mellitus (T2DM), and osteoporosis (OP) were assessed.

RESULTS

The increased LNSalC levels (>2.8  nmol/l) had an 83.3% specificity (SP) and a 31.3% sensitivity (SN) for predicting the biochemical diagnosis of SH. The increased LNSalC had an 85.2% SP and a 55.6% SN for predicting the presence of hypertension, T2DM, and OP, while the combination of LNSalC >1.4  nmol/l (cutoff with 100% SN) plus 1 mg DST >50  nmol/l had an 88.9% SN and an 85.2% SP (similar to SH criterion at enrollment).

CONCLUSIONS

In AI patients, LNSalC measured by LC-MS/MS appears to be useful in combination with 1 mg DST for diagnosing SH, while it is not useful as a single criterion.

Diabetes mellitus type 2: a new indication for hypercortisolism screening?

Current review discusses novel data concerning prevalence of Cushing syndrome without characteristic clinical signs among patients with type 2 diabetes mellitus. We also provide detailed analysis of difficulties in diagnostics and management of this condition

Current status and controversies in adrenal incidentalomas

Adrenal incidentalomas (AI) are serendipitously discovered lesions during abdominal imaging studies that need to be investigated for evidence of hormonal hypersecretion and/or malignancy. Because imaging modalities can reliably identify lesions that carry a high risk of malignancy, we focus on the identification of hypersecretory lesions and those with subclinical activity, particularly Cushing syndrome. Because diverse diagnostic tests and cut-offs are employed, the prevalence of hypersecretory AI varies widely, and there is controversy regarding their long-term sequelae. In this article we provide information regarding current radiological means to define the nature of AI, and the most appropriate biochemical tests for delineating hypersecretory states. We also discuss the duration and intensity of AI follow-up as well as the identification of AI that require specific therapeutic intervention.

Subclinical Cushing's syndrome

The routine use of abdominal procedure has significantly increased the incidental finding of adrenal masses. The prevalence of these tumors, commonly defined as adrenal incidentalomas, ranges between 2-3% in autopsy and 4% in radiological series, reaching 5-8% in oncological studies and increasing with patients age. Although clinically silent, in 5-20% of cases, adrenal incidentalomas are responsible for a subtle cortisol overproduction, commonly defined as "subclinical Cushing's syndrome" (SCS). This term is used to describe autonomous cortisol secretion in patients who don't have the typical signs and symptoms of hypercortisolism. The optimal strategy for identification and management of SCS is unknown; the standard biochemical tests used to screen for overt Cushing's syndrome are generally ill-suited to the assessment of patients who have no, or only very mild signs of cortisol excess, then many tests aimed to study the hypothalamus-pituitary-adrenal axis (HPA) axis do not have sufficient sensitivity to recognize very mild degree of cortisol excess. An increased frequency of hypertension, central obesity, impaired glucose tolerance or diabetes, hyperlipemia and osteoporosis has been described in patients with SCS since patients are exposed to a chronic albeit slight, cortisol excess; however, there is not evidence-based demonstration of long term complications and, consequently, the management of this condition is largely empirical. Adrenalectomy or medical management of associated disease has been indicated as therapeutic options due to lack of data demonstrating the superiority of a surgical or non-surgical treatment.

Adrenal incidentaloma

Adrenal incidentaloma is a common clinical problem and its prevalence, in radiological studies, comes close to that of autoptic data as a result of imaging technological advances. The diagnostic challenge is to distinguish the majority of benign lesions from other masses, either malignant or hormone secreting, which require further therapy. The imaging evaluation (unenhanced CT and MRI) can differentiate malignant to benign lesions because the benign lesions have high lipid content. All patients should be tested for hypercortisolism and pheochromocytoma whereas aldosteronism should be tested in hypertensive patients only. The optimal diagnostic management for adrenal incidentaloma is still controversial, and the endocrinologist must devise a cost-effective approach taking into account the extensive endocrine work-up and imaging investigations that may be necessary. A tailored strategy may be based on the selection of patients at increased risk who require a careful and extensive follow-up among the vast majority of patients who require a simplified follow-up.

Adrenal incidentalomas

The term adrenal incidentaloma (AI) is usually defined as an adrenal mass unexpectedly detected through an imaging procedure performed for reasons a priori unrelated to adrenal dysfunction or suspected dysfunction. The preferred approach to their management in terms of diagnosis, follow-up, and treatment remain controversial despite a state-of-the-science conference sponsored by the U.S. National Institutes of Health. Although most experts' recommendations tend to be relatively minor variations of the conference's approach, dissenting voices have been heard. Despite their frequent appearance, the challenge remains to recognize and treat the small percentage of AI that do pose a significant risk, either because of their hormonal activity or because of their malignant histology, while leaving the rest alone. Although the differential diagnosis of an incidentally discovered mass is quite extensive, most AIs are non-secreting cortical adenomas. The noninvasive differentiation of benign and malignant lesions depends upon imaging characteristics, and sometimes radiologic diagnosis can be definitive, but often it is not, Among function lesions, autonomous cortisol production seems to be the most common and may be associated with increased cardiovascular risk and clinical features of the "metabolic syndrome." Follow-up of cases in which a specific diagnosis is not made initially involves assessment for growth and development of hormonal function, but even here, controversy about the extent of evaluation persists.

Subclinical Cushing's syndrome: definition and management

Subclinical Cushing's syndrome is an ill-defined endocrine disorder that may be observed in patients bearing an incidentally found adrenal adenoma. The concept of subclinical Cushing's syndrome stands on the presence of ACTH-independent cortisol secretion by an adrenal adenoma, that is not fully restrained by pituitary feed-back. A hypercortisolemic state of usually minimal intensity may ensue and eventually cause harm to the patients in terms of metabolic and vascular diseases, and bone fractures. However, the natural history of subclinical Cushing's syndrome remains largely unknown. The present review illustrates the currently used methods to ascertain the presence of subclinical Cushing's syndrome and the surrounding controversy. The management of subclinical Cushing's syndrome, that remains a highly debated issue, is also addressed and discussed. Most of the recommendations made in this chapter reflects the view and the clinical experience of the Authors and are not based on solid evidence.

Urine steroid metabolomics as a biomarker tool for detecting malignancy in adrenal tumors

CONTEXT

Adrenal tumors have a prevalence of around 2% in the general population. Adrenocortical carcinoma (ACC) is rare but accounts for 2-11% of incidentally discovered adrenal masses. Differentiating ACC from adrenocortical adenoma (ACA) represents a diagnostic challenge in patients with adrenal incidentalomas, with tumor size, imaging, and even histology all providing unsatisfactory predictive values.

OBJECTIVE

Here we developed a novel steroid metabolomic approach, mass spectrometry-based steroid profiling followed by machine learning analysis, and examined its diagnostic value for the detection of adrenal malignancy.

DESIGN

Quantification of 32 distinct adrenal derived steroids was carried out by gas chromatography/mass spectrometry in 24-h urine samples from 102 ACA patients (age range 19-84 yr) and 45 ACC patients (20-80 yr). Underlying diagnosis was ascertained by histology and metastasis in ACC and by clinical follow-up [median duration 52 (range 26-201) months] without evidence of metastasis in ACA. Steroid excretion data were subjected to generalized matrix learning vector quantization (GMLVQ) to identify the most discriminative steroids.

RESULTS

Steroid profiling revealed a pattern of predominantly immature, early-stage steroidogenesis in ACC. GMLVQ analysis identified a subset of nine steroids that performed best in differentiating ACA from ACC. Receiver-operating characteristics analysis of GMLVQ results demonstrated sensitivity = specificity = 90% (area under the curve = 0.97) employing all 32 steroids and sensitivity = specificity = 88% (area under the curve = 0.96) when using only the nine most differentiating markers.

CONCLUSIONS

Urine steroid metabolomics is a novel, highly sensitive, and specific biomarker tool for discriminating benign from malignant adrenal tumors, with obvious promise for the diagnostic work-up of patients with adrenal incidentalomas.

Clinical outcome of subclinical Cushing's syndrome after surgical and conservative treatment

Subclinical Cushing's syndrome (SCS), a subtle cortisol hypersecretion from an adrenal tumor, may be a common adrenal disease. However, the cardiovascular prognosis and the optimal surgical and conservative treatment in SCS remain elusive. The present study was undertaken to evaluate the prevalence of cardiovascular risk factors in 16 SCS cases, their relationships to cortisol secretory activities, and the clinical outcome after surgical and medical treatment. The prevalence of hypertension, impaired glucose tolerance (IGT), diabetes mellitus (DM), dyslipidemia and obesity in our SCS cases were 56%, 50%, 50%, and 19%, respectively, and 75% of cases were associated with two or more cardiovascular risk factors. In our series, 24-h urinary free-cortisol excretion showed a significant positive correlation with HbA1c and a negative correlation with high-density lipoprotein-cholesterol, but no correlation with age, body mass index, blood pressure or glycemic and lipid profile was found. Eight cases underwent unilateral adrenalectomy (operated (OP) group); the remaining eight cases were a conservative-treatment group (non-OP group). The number of cardiovascular risk factors decreased significantly in the OP group, but not in the non-OP group. In terms of differential changes in risk factors between the groups, more significant improvements of hypertension, dyslipidemia and IGT/DM were observed in the OP group than in the non-OP group. In conclusion, the present study showed the increased prevalence of cardiovascular risk factors in SCS patients with mild hypercortisolism related to impaired glucose/lipid metabolism. Adrenalectomy decreased accumulated cardiovascular risk factors in certain SCS patients, suggesting the possible involvement of mild hypercortisolism in the development of cardiovascular risk factors in SCS.

Endocrine incidentalomas--challenges imposed by incidentally discovered lesions

Endocrine glands are among the organs that most frequently harbor incidentally discovered lesions. Pituitary, thyroid, parathyroid and adrenal incidentalomas are increasingly encountered in everyday practice with variable clinical implications. The major concerns are the risks of malignancy and hormonal hypersecretion mostly in the form of subclinically functioning tumors. Pituitary incidentalomas are usually microadenomas and most of the time clinically unimportant; however, incidentally discovered larger lesions require a more careful diagnostic and therapeutic approach. Thyroid incidentalomas are extremely common; exclusion of malignancy is the main concern in this clinical setting. Although parathyroid adenomas are not uncommon, these lesions are frequently missed owing to their small size and due to clinical unawareness. Adrenal incidentalomas carry a small but finite risk of malignancy. An intriguing challenge regarding incidentally discovered adrenal lesions is that a substantial proportion is associated with hormonal alterations, mainly in the form of subtle cortisol excess. Although still largely controversial, evidence is emerging that so-called subclinical hypercortisolism may not be completely harmless. The best biochemical criterion of subtle cortisol excess remains elusive. Surgical intervention in selected cases results in some beneficial effects, but more data are required in order to routinely support surgery in this clinical setting. This Review provides a brief overview of the prevalence, clinical effect and management of endocrine incidentalomas with a focus on data regarding the diagnostic and therapeutic challenges imposed by incidentally discovered adrenal lesions.

Cohort study of patients with adrenal lesions discovered incidentally

Background

This prospective cohort study investigated the incidence, clinical features and natural history of incidentally discovered adrenal mass lesions (adrenal incidentaloma, AI) in an unselected population undergoing radiological examination.

Methods

During an 18-month period, all patients with AI were reported prospectively from all 19 radiology departments in western Sweden. Inclusion criteria were: incidentally discovered adrenal enlargement or mass lesion in patients without extra-adrenal malignancy on detection. Clinical and biochemical evaluation was performed on inclusion and after 24 months. Computed tomography (CT) of the adrenals was scheduled at 4, 12 and 24 months. Magnetic resonance imaging was performed for lesions larger than 20 mm. The indications for surgical excision were: hormone activity, lesion diameter more than 30 mm, lesion growth or other radiological features suspicious of malignancy.

Results

Of 534 patients assessed for eligibility, 226 (mean age 67 years, 62·4 per cent women; mean lesion diameter 23·9 mm, 22·6 per cent bilateral) fulfilled the inclusion criteria. Mean follow-up was 19·0 months. After baseline evaluation, 14 patients had surgery owing to primary hyperaldosteronism (3), catecholamine-producing tumour (1), tumour size (6), size and indication of subclinical hypercortisolism (3) and metastasis (1). No hypersecreting lesions were confirmed during follow-up; one patient underwent adrenalectomy for a suspected phaeochromocytoma (adrenocortical adenoma at histopathology). No primary adrenal malignancy was found.

Conclusion

In this prospective cohort study 6·6 per cent of patients with an AI had surgery and benign hormone-producing tumours were verified in 3·1 per cent. Repeat CT and hormone evaluation after 2 years did not increase the sensitivity for diagnosis of malignant or hormone-producing tumours.

Clinical review: Diagnosis and treatment of subclinical hypercortisolism

CONTEXT

Subclinical hypercortisolism (SH) is a condition of biochemical cortisol excess without the classical signs or symptoms of overt hypercortisolism. It is thought to be present in the 5-30% of patients with incidentally discovered adrenal mass (adrenal incidentalomas), which in turn are found in 4-7% of the adult population. Therefore, SH has been suggested to be present in 0.2-2.0% of the adult population. Some studies suggested that this condition is present in 1-10% of patients with diabetes or established osteoporosis. The present manuscript reviews the literature on diagnostic procedures and the metabolic effect of the recovery from SH.

EVIDENCE ACQUISITION

A PubMed search was used to identify the available studies. The most relevant studies from 1992 to November 2010 have been included in the review.

EVIDENCE SYNTHESIS

The available data suggest that SH may be associated with chronic complications, such as hypertension, diabetes mellitus, overweight/obesity, and osteoporosis. The available intervention studies suggest that the recovery from SH may lead to the improvement of hypertension and diabetes mellitus. A retrospective study suggests that this beneficial effect could be predicted before surgery.

CONCLUSIONS

SH is suggested to be associated with some chronic complications of overt cortisol excess. Recovery from this condition seems to improve these complications. However, a large, prospective, randomized study is needed to confirm this hypothesis and to establish the best diagnostic approach to identify patients with adrenal incidentalomas who can benefit from surgery.

High prevalence of subclinical hypercortisolism in patients with bilateral adrenal incidentalomas: a challenge to management

OBJECTIVE

The prevalence of subclinical hypercortisolism (SH) in unilateral incidentalomas (UI) has been extensively studied; however, patients with bilateral incidentalomas (BI) have not been thoroughly investigated. We therefore aimed to describe the characteristics of patients with BI compared to their unilateral counterparts. The surgical outcome in a small number of patients is reported.

DESIGN

Observational retrospective study in a single secondary/tertiary centre.

PATIENTS

One hundred and seventy-two patients with adrenal incidentalomas (41 with BI).

MEASUREMENTS

Morning cortisol (F), ACTH, dehydroepiandrosterone sulphate (DHEA-S), midnight F, 24-h urine collection for cortisol (UFC), low-dose dexamethasone suppression test (LDDST), fasting glucose, insulin, and oral glucose tolerance test (OGTT). Primarily, SH was defined as F-post-LDDST>70 nmol/l and one more abnormality; several diverse cut-offs were also examined.

RESULTS

No difference was noted in age, body mass index, or prevalence of diabetes and impaired glucose tolerance between patients with UI and those with BI. Patients with BI had higher F-post-LDDST (119·3 ± 112·8 vs 54·3 ± 71·5 nmol/l, P<0·001) and lower DHEA-S (1·6 ± 1·5 vs 2·5 ± 2·3 μmol/l, P=0·003) but similar UFC, ACTH and midnight F levels, compared to UI. SH was significantly more prevalent in BI (41·5%vs 12·2%, P<0·001). Fourteen patients were operated on; four underwent bilateral interventions. In 10 patients, unilateral adrenalectomy on the side of the largest lesion resulted in significant improvement in F-post-LDDST (P=0·008) and a decrease in midnight F (P=0·015) levels.

CONCLUSIONS

Subclinical hypercortisolism is significantly more prevalent in bilateral incidentaloma patients, posing great dilemmas for its optimum management.

Pros and cons of screening for occult Cushing syndrome

Systematic screening studies performed mainly in patients with diabetes mellitus have revealed an unexpectedly high prevalence of occult Cushing syndrome. Such studies may provide a rationale for systematically screening obese patients with type 2 diabetes mellitus. However, a screening strategy is only justified if it is supported by enough evidence of its efficacy and if the benefits will outweigh drawbacks. To date, the natural history of occult Cushing syndrome and its possible effect on long-term morbidity are unknown. The clinical spectrum of occult Cushing syndrome and its relatively low prevalence may potentially negatively affect the performance of endocrine tests used to diagnose overt Cushing syndrome and generate false positives. Whether the cure of occult Cushing syndrome favorably influences clinical outcomes and is more beneficial than treatment of diabetes mellitus and cardiovascular risk factors with currently available pharmacological tools remains to be demonstrated. Last, the acceptability of a screening program by professionals and the health-care system in terms of workload and costs is highly questionable. Thus, an assessment of the indications for and against screening for occult Cushing syndrome on the basis of currently available data suggests that, to date, the cons surpass the pros.

Accuracy of several parameters of hypothalamic-pituitary-adrenal axis activity in predicting before surgery the metabolic effects of the removal of an adrenal incidentaloma

CONTEXT

It is unknown whether the metabolic effects of the removal of an adrenal incidentaloma (AI) can be predicted by the assessment of cortisol hypersecretion before surgery.

OBJECTIVE

To evaluate the accuracy of several criteria of hypothalamic-pituitary-adrenal axis activity in predicting the metabolic outcome after adrenalectomy.

DESIGN

Retrospective longitudinal study.

PATIENTS

In 55 surgically treated AI patients (Group 1) before surgery and in 53 nontreated AI patients (Group 2) at the baseline, urinary free cortisol (UFC), cortisol after 1 mg overnight dexamethasone-suppression test (1 mg-DST), ACTH, and midnight serum cortisol (MSC) were measured. In Groups 1 and 2, metabolic parameters were evaluated before and 29.6 ± 13.8 months after surgery and at the baseline and after 35.2 ± 10.9 months respectively.

MAIN OUTCOME MEASURES

The improvement/worsening of weight, blood pressure, glucose, and cholesterol levels (endpoints) was defined by the presence of a >5% weight decrease/increase and following the European Society of Cardiology or the ATP III criteria respectively. The accuracy of UFC, 1 mg-DST, ACTH, and MSC, singularly taken or in combination, in predicting the improvement/worsening of ≥ 2 endpoints was calculated.

RESULTS

The presence of ≥ 2 among UFC>70 μg/24 h (193 nmol/l), ACTH<10 pg/ml (2.2 pmol/l), 1 mg-DST>3.0 μg/dl (83 nmol/l) (UFC-ACTH-DST criterion) had the best accuracy in predicting the endpoints' improvement (sensitivity (SN) 65.2%, specificity (SP) 68.8%) after surgery. In the nontreated AI patients, this criterion predicted the worsening of ≥ 2 endpoints (SN 55.6%, SP 82.9%).

CONCLUSIONS

The UFC-ACTH-DST criterion seems to be the best for predicting the metabolic outcome in surgically treated AI patients.

Is metabolic syndrome a mild form of Cushing's syndrome?

The Metabolic Syndrome is a diagnosis of increasing prevalence that is noted to share multiple clinical features with Cushing's syndrome. Several studies suggest abnormalities in the Hypothalamic-Pituitary-Adrenal axis to be associated with this disease and tissue-specific hypercortisolemia is being investigated as a possible contributing factor. More research is needed to explore the relation between cortisol and the metabolic syndrome which, if confirmed, will have major therapeutic and public health implications.

Adrenal incidentalomas and subclinical Cushing's syndrome

The issue of cortisol secretion by adrenal masses discovered incidentally in the course of evaluation for an unrelated reason (Subclinical Cushing's Syndrome) is among the most controversial and contentious issues in clinical endocrine practice. This derives from our relatively poor ability to accurately determine clinically those at increased risk among the majority who are not, the significant limitations of available diagnostic tests, the lack of a gold standard for diagnosis or even universally agreed criteria for diagnosis. A consensus for diagnostic criteria would be a good first step on which to base the kinds of studies needed to address our uncertainties. In the meantime, we must be careful to recognize the limitations of the current evidence avoid the pitfalls of overestimation of disease prevalence and of the benefits of therapy resulting from advances in diagnostic imaging and sophisticated laboratory testing. There remains an essential role for clinical judgment.