Endogenous subclinical hypercortisolism: Diagnostic uncertainties and clinical implications

Plasma Steroid Profiling Combined With Machine Learning for the Differential Diagnosis in Mild Autonomous Cortisol Secretion From Nonfunctioning Adenoma in Patients With Adrenal Incidentalomas

OBJECTIVE

To assess the diagnostic value of combining plasma steroid profiling with machine learning (ML) in differentiating between mild autonomous cortisol secretion (MACS) and nonfunctioning adenoma (NFA) in patients with adrenal incidentalomas.

METHODS

The plasma steroid profiles data in the laboratory information system were screened from January 2021 to December 2023. EXtreme Gradient Boosting was applied to establish diagnostic models using plasma 24-steroid panels and/or clinical characteristics of the subjects. The SHapley Additive exPlanation (SHAP) method was used for explaining the model.

RESULTS

Seventy-six patients with MACS and 86 patients with NFA were included in the development and internal validation cohort while the external validation cohort consisted of 27 MACS and 21 NFA cases. Among 5 ML models evaluated, eXtreme Gradient Boosting demonstrated superior performance with an area under the curve of 0.77 using 24 steroid hormones. The SHAP method identified 5 steroids that exhibited optimal performance in distinguishing MACS from NFA, namely dehydroepiandrosterone, 11-deoxycortisol, 11β-hydroxytestosterone, testosterone, and dehydroepiandrosteronesulfate. Upon incorporating clinical features into the model, the area under the curve increased to 0.88, with a sensitivity of 0.77 and specificity of 0.82. Furthermore, the results obtained through SHAP revealed that lower levels of testosterone, dehydroepiandrosterone, low-density lipoprotein cholesterol, body mass index, and adrenocorticotropic hormone along with higher level of 11-deoxycortisol significantly contributed to the identification of MACS in the model.

CONCLUSIONS

We have elucidated the utilization of ML-based steroid profiling to discriminate between MACS and NFA in patients with adrenal incidentalomas. This approach holds promise for distinguishing these 2 entities through a single blood collection.

Management of Adrenal Cortical Adenomas: Assessment of Bone Status in Patients with (Non-Functioning) Adrenal Incidentalomas

Our aim is to analyse the bone profile in adults with (non-functioning) adrenal incidentalomas (AIs), specifically addressing the impact of autonomous cortisol secretion (ACS). This narrative review, based on a PubMed search from inception to February 2023 (case reports, non-ACS, and other secondary causes of osteoporosis were excluded), included 40 original studies, a total of 3046 patients with female prevalence (female:male ratio of 1921:1125), aged between 20.5 and 95.5 years old. This three decade-based analysis showed that 37 studies provided dual-energy X-ray absorptiometry (DXA) information; another five studies reports results on bone micro-architecture, including trabecular bone score (TBS), spinal deformity index, and high-resolution peripheral quantitative computed tomography; 20 cohorts included data on bone turnover markers (BTMs), while four longitudinal studies followed subjects between 1 and 10.5 years old (surgical versus non-adrenalectomy arms). Post-dexamethasone suppression test (DST) cortisol was inversely associated with bone mineral density (BMD). TBS predicted incidental vertebral fractures (VFx) regardless of BMD, being associated with post-DST cortisol independently of age and BMD. Low BTMs were identified in ACS, but not all studies agreed. An increased prevalence of ACS-related osteoporosis was confirmed in most studies (highest prevalence of 87.5%), as well as of VFx, including in pre-menopause (42.5%), post-menopause (78.6%), and male patients (72.7%) depending on the study, with a 10-fold increased incidental VFx risk up to a 12-fold increased risk after a 2-year follow-up. No specific medication against osteoporosis is indicated in ACS, but adrenalectomy (according to four studies) should be part of the long-term strategy. This bone profile case sample-based study (to our knowledge, one of the largest of its kind) showed that AIs, including the subgroup designated as having ACS, embraces a large panel of osseous complications. The level of evidence remains far from generous; there are still no homogenous results defining ACS and identifying skeletal involvement, which might be a consequence of different investigation clusters underling adrenal and bone assessments over time. However, bone status evaluations and associated therapy decisions remain an essential element of the management of adults with AIs-ACS.

Cortisol and the Dexamethasone Suppression Test as a Biomarker for Melancholic Depression: A Narrative Review

The dexamethasone suppression test (DST) assesses the functionality of the HPA axis and can be regarded as the first potential biomarker in psychiatry. In 1981, a group of researchers at the University of Michigan published a groundbreaking paper regarding its use for diagnosing melancholic depression, reporting a diagnostic sensitivity of 67% and a specificity of 95%. While this study generated much enthusiasm and high expectations in the field of biological psychiatry, subsequent studies produced equivocal results, leading to the test being rejected by the American Psychiatric Association. The scientific reasons leading to the rise and fall of the DST are assessed in this review, suggestions are provided as to how the original test can be improved, and its potential applications in clinical psychiatry are discussed. An improved, standardized, and validated version of the DST would be a biologically meaningful and useful biomarker in psychiatry, providing a tool for clinicians caring for depressed patients in the areas of diagnosis, treatment, and prognosis, and predicting the risk of suicide. Additionally, such a test could be a crucial part in the generation of biologically homogenous patient cohorts, necessary for the successful development of new psychotropic medications.

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.

Cardiovascular complications of mild autonomous cortisol secretion

Adrenal incidentalomas (AI) may be associated with a mild autonomous cortisol secretion (MACS) in up to one third of cases. There is growing evidence that MACS patients actually present increased risk of cardiovascular disease and higher mortality rate, driven by increased prevalence of known cardiovascular risk factors, as well as accelerated cardiovascular remodelling. Adrenalectomy seems to have cardiometabolic beneficial effects in MACS patients but their management is still a debated topic due to the lack of high-quality studies. Several studies suggested that so called "non-functioning" AI may be actually "functioning" with an associated increased cardiovascular risk. Although the individual cortisol sensitivity and peripheral activation have been recently suggested to play a role in influencing the cardiovascular risk even in apparently eucortisolemic patients, to date the degree of cortisol secretion, as mirrored by the cortisol levels after dexamethasone suppression test remains the best predictor of an increased cardiovascular risk in AI patients. However, whether or not the currently used cut-off set at 50 nmol/L for cortisol levels after dexamethasone suppression could be considered completely reliable in ruling out hypercortisolism remains unclear.

Markers of Subclinical Cardiovascular Disease in Patients with Adrenal Incidentaloma

Due to the growing availability of imaging examinations the percentage of patients with incidentally diagnosed adrenal tumors has increased. The vast majority of these lesions are benign, non-functioning adenomas, although according to various estimates even up to 30%-50% of patients with adrenal incidentaloma may present biochemical hypercortisolemia, without typical clinical features of Cushing's syndrome. Adrenal adenomas secreting small amounts of glucocorticoids may cause morphological and functional changes in the myocardium and blood vessels. Early stages of cardiovascular remodeling may be observed among asymptomatic patients with adrenal adenoma. Vascular changes precede the development of cardiovascular diseases and can increase morbidity and mortality in patients with adrenal incidentaloma. This risk may result not only from the traditional risk factors. Seemingly hormonally inactive adrenal tumors can indeed produce small amounts of glucocorticoids that have metabolic implications. Therefore, evaluation of patients with incidental adrenal findings presenting with subclinical cardiovascular disease seems of particular importance.

Cardiometabolic profile of non-functioning and autonomous cortisol-secreting adrenal incidentalomas. Is the cardiometabolic risk similar or are there differences?

OBJECTIVE

To study the differences in the cardiometabolic profile between patients with non-functioning adrenal incidentalomas (NFAI) and incidentalomas with autonomous cortisol secretion (ACS).

METHODS

A total of 149 patients with adrenal incidentalomas were retrospectively evaluated and followed-up for a mean time of 34.6 months at Departments of Endocrinology and Metabolic Diseases Units of four tertiary Spanish hospitals. Patients were grouped as NFAI or ACS adenomas based on two cutoffs in the dexamethasone suppression test (DST): 3.0 µg/dl (NFAI_DST3 or ACS_DST3) and 1.8 µg/dl (ACS_DST1.8 and NFAI_DST1.8).

RESULTS

The mean age of both groups was 62.0 (10.31) and was similar in ACS and NFAI. The prevalence of diabetes, high blood pressure, cardiovascular, and cerebrovascular disease was higher in ACS than in NFAI, but differences only reached statistical significance for cerebrovascular disease using the 3.0 µg/dl cutoff (15.8% vs 2.3%, p = 0.01) and for diabetes using the 1.8 µg/dl cutoff (38.0% vs 22.0%, p = 0.04). No differences were found in the prevalence of dyslipidemia. The prevalence of obesity was lower in patients with ACS than in NFAI 26.3% vs 39.2%, p = 0.18 (NFAI_DST3 vs ACS_DST3) and 32.1% vs 40.6%, p = 0.56 (ACS_DST1.8 vs NFAI_DST1.8), but the differences did not reach statistical significance. Maximum adenoma diameter (R-squared = 0.15, p < 0.001) and cerebrovascular disease (OR = 1.59, p = 0.04) were the only parameters that could be predicted by the DST. The DST was an inadequate predictor of clinical (systolic and diastolic blood pressure, body mass index), hormonal (DHEAS, ACTH, UFC, and basal serum cortisol), biochemical (glucose, cholesterol, LDL, HDL, and triglycerides), and other radiological (laterality, lipid content) parameters. Throughout the follow-up, patients did not develop overt Cushing's Syndrome; three NFAI_DST3 developed ACS_DST3, eight NFAI_DST1.8 developed ACS_DST1.8, and one NFAI_DST1.8 progressed to ACS_DST3. In both groups (NFAI and ACS) the metabolic profile remained stable.

CONCLUSIONS

Our data suggest higher prevalence of diabetes and cerebrovascular disease in ACS patients compared with NFAI. However, probably because of the small sample size, the differences only reached statistical significance using the cutoffs of 1.8 µg/dl for diabetes and 3.0 µg/dl for cerebrovascular disease. Patients with ACS and NFAI rarely progress to more aggressive forms of hypercortisolism, and the metabolic profile usually remains stable during the follow-up.

Accuracy of new recommendations for adrenal incidentalomas in the evaluation of excessive cortisol secretion and follow-up

OBJECTIVE

To evaluate whether the 2016 European Society of Endocrinology (ESE) recommendations for the management of adrenal incidentalomas accurately classifies those patients who do not require further follow-up.

DESIGN AND METHODS

Single centre retrospective study. From 2010 to 2015, 130 patients with adrenal incidentaloma were evaluated and followed-up. Clinical, analytical and radiological data were recorded and the presence of comorbidities was assessed. Patients were grouped as nonfunctional or subclinical Cushing syndrome according to American guidelines; and nonfunctional, possible autonomous cortisol secretion and autonomous cortisol secretion, according to ESE guidelines.

RESULTS

Based on American guidelines, 94% of patients had nonfunctional adrenal incidentalomas and 6% had subclinical Cushing syndrome. Based on ESE guidelines, patients were classified into nonfunctional (54%), possible autonomous cortisol secretion (40%) and autonomous cortisol secretion (6%) groups. No differences were observed in demographic characteristics and comorbidities between groups in either classification. Following ESE guidelines, no patient in the nonfunctional group was reclassified into the possible autonomous or autonomous cortisol secretion groups during follow-up, but one patient in the possible autonomous cortisol secretion group was reclassified into the autonomous cortisol secretion group. Also, 30 patients included in the groups of possible autonomous or autonomous cortisol secretion experienced progression of a comorbidity associated with cortisol excess, with diabetes mellitus as the most frequent comorbidity observed.

CONCLUSION

Although adrenal incidentalomas with an excess of cortisol secretion were more frequently diagnosed with the new ESE recommendations, patients who did not require longer follow-up after first evaluation were accurately classified.

Nonfunctioning adrenal incidentaloma: A novel predictive factor for metabolic syndrome

CONTEXT

Although metabolic syndrome has been studied in patients with autonomous cortisol secretion, there are limited data for those with nonfunctioning adrenal incidentaloma (NFAI).

OBJECTIVE

To assess metabolic syndrome frequency in NFAI patients and controls without adrenal adenoma according to World Health Organization (WHO), National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III), American Association of Clinical Endocrinologists/American College of Endocrinology (AACE/ACE) and International Diabetes Federation (IDF) criteria.

DESIGN

Retrospective and transversal study.

PATIENTS

Seventy-four NFAI and 90 controls were evaluated. NFAI diagnosis was established according to current guidelines. The control group was selected based on normal adrenal imaging examinations.

MEASUREMENTS

Subjects were categorized by metabolic syndrome presence according to WHO, NCEP-ATP III, AACE/ACE and IDF.

RESULTS

Age, gender, ethnicity, body mass index, smoking, menopause, statin and fibrate use were comparable between patients and controls. The frequency of prediabetes, dyslipidaemia and hypertension as well as waist circumference were significantly higher in the NFAI patients compared to the controls. The metabolic syndrome frequency in the NFAI group was significantly higher compared to the normal adrenal group: WHO: 69.2% × 31.0% (P < 0.001); NCEP-ATP III: 81.7% × 44.9% (P < 0.001); AACE/ACE: 77.1% × 31.9% (P < 0.001); IDF: 78.6% × 45.5% (P < 0.001). Logistic regression analysis showed that NFAI was a predictor of metabolic syndrome according to WHO (P = 0.001), NCEP-ATP III (P = 0.005) and AACE/ACE (P = 0.007).

CONCLUSIONS

Metabolic syndrome is frequently found in patients with NFAI, and this frequency is higher in NFAI patients than in those with normal adrenal imaging.

Clinical Parameters to Distinguish Silent Corticotroph Adenomas from Other Nonfunctioning Pituitary Adenomas

BACKGROUND

It is difficult to distinguish silent corticotroph adenomas (SCAs) from other nonfunctioning pituitary adenomas (NFPAs) preoperatively. This study aimed to determine the preoperative clinical parameters associated with SCAs.

METHODS

This was a retrospective single-center study of patients who underwent surgery for NFPAs during 2011-2016 in our tertiary hospital and who had preoperative combined pituitary function test (CPFT) and immunohistochemical staining results available. After we excluded patients with increased 24-hour urinary free cortisol to preclude overt Cushing's disease, 341 patients were finally enrolled. The medical records, including the CPFT and immunohistochemistry results, of the patients were reviewed.

RESULTS

The age and tumor size were similar between patients with SCAs and other NFPAs. The SCA group had a greater proportion of women (89.2% vs. 57.6%, P < 0.001), cavernous sinus invasion (35.1% vs. 20.7%, P = 0.047), and intratumoral hemorrhage on preoperative sella magnetic resonance imaging (32.4% vs. 9.2%, P < 0.001) compared with the NFPA group. In the preoperative CPFT, the cortisol response was not significantly different between groups. However, the peak adrenocorticotropic hormone (ACTH) (67.80 ± 49.83 vs. 85.67 ± 78.97 pg/mL, P = 0.061) tended to be lower, and the ΔACTH (53.71 ± 50.14 vs. 72.67 ± 75.82 pg/mL, P = 0.046) was significantly lower in SCAs. After we excluded patients with preoperative hypopituitarism caused by mass effects, the peak ACTH (69.39 ± 39.45 vs. 119.75 ± 89.84 pg/mL, P = 0.001) and ΔACTH (58.58 ± 36.51 vs. 107.66 ± 86.05 pg/mL, P = 0.001) were significantly lower in SCAs than in other NFPAs.

CONCLUSIONS

Female sex, cavernous sinus invasion, intratumoral hemorrhage on sella magnetic resonance imaging, and decreased ACTH response in the CPFT are independent indicators of SCAs.

Nonfunctioning adrenal incidentaloma affecting central blood pressure and arterial stiffness parameters

PURPOSE

Recently, cardiovascular risk is thought to be increased in patients with nonfunctioning adrenal incidentaloma (NFAI). There are no sufficient studies in the literature to evaluate this situation in NFAI patients without cardiovascular risk. The objective of this study is to compare peripheral and central blood pressure and arterial stiffness between patients with NFAI and healthy volunteers (of a similar age, gender and body mass index as the NFAI group) who have no traditional cardiovascular risk factors and autonomous cortisol secretion, with pulse wave analysis (PWA).

METHODS

In this cross-sectional study, we evaluated 35 NFAI patients who have no traditional cardiovascular risk factors and 35 healthy volunteers. PWA was performed in the participants of similar gender, age and body mass index, with a Mobil-O-Graph PWA/ABPM (I.E.M. GmBH, Stolberg, Germany) device. Radiological and biochemical data were obtained retrospectively in the NFAI group.

RESULTS

In our study, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), central SBP, central DBP, peripheral vascular resistance, augmentation pressure (AP), heart rate-corrected augmentation index (Aix@75) and pulse wave velocity (PWV) values were significantly higher in the NFAI group compared to the control group. In addition, peripheral and central blood pressure and arterial stiffness parameters were correlated with age and duration of NFAI diagnosis of more than 1 year.

CONCLUSIONS

NFAIs are known as cardiometabolically innocent, but in our study, both peripheral and central blood pressure values and arterial stiffness parameters were negatively affected in patients diagnosed with NFAI who have no traditional cardiovascular risk factors. These patients are at risk of cardiovascular diseases.

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

OBJECTIVES

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

DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

MECHANISMS IN ENDOCRINOLOGY: Endogenous subclinical hypercortisolism and bone: a clinical review

In recent years, the condition of subclinical hypercortisolism (SH) has become a topic of growing interest. This is due to the fact that SH prevalence is not negligible (0.8-2% in the general population) and that, although asymptomatic, this subtle cortisol excess is not harmless, being associated with an increased risk of complications, in particular of osteoporosis and fragility fractures. As specific symptoms of hypercortisolism are absent in SH, the SH diagnosis relies only on biochemical tests and it is a challenge for physicians. As a consequence, even the indications for the evaluation of bone involvement in SH patients are debatable and guidelines are not available. Finally, the relative importance of bone density, bone quality and glucocorticoid sensitivity in SH is a recent field of research. On the other hand, SH prevalence seems to be increased in osteoporotic patients, in whom a vertebral fracture may be the presenting symptom of an otherwise asymptomatic cortisol excess. Therefore, the issue of who and how to screen for SH among the osteoporotic patients is widely debated. The present review will summarize the available data regarding the bone turnover, bone mineral density, bone quality and risk of fracture in patients with endogenous SH. In addition, the role of the individual glucocorticoid sensitivity in SH-related bone damage and the problem of diagnosing and managing the bone consequences of SH will be reviewed. Finally, the issue of suspecting and screening for SH patients with apparent primary osteoporosis will be addressed.

Adrenalectomy for Cushing's syndrome: do's and don'ts

Aim. To present specific aspects of adrenalectomy for Cushing’s syndrome (CS) by introducing well established aspects (“do’s”) and less known aspects (“don’ts”).

Material and Method. This is a narrative review.

Results. The “do’s” for laparoscopic adrenalectomy (LA) are the following: it represents the “gold standard” for secretor and non-secretor adrenal tumors and the first line therapy for CS with an improvement of cardio-metabolic co-morbidities; the success rate depending on the adequate patients’ selection and the surgeon’s skills. The “don’ts” are large (>6-8 centimeters), locally invasive, malignant tumors requiring open adrenalectomy (OA). Robotic adrenalectomy is a new alternative for LA, with similar safety and conversion rate and lower pain drugs use. The “don’ts” are the following: lack of randomized controlled studies including oncologic outcome, different availability at surgical centers. Related to the sub-types of CS, the “do’s” are the following: adrenal adenomas which are cured by LA, while adrenocortical carcinoma (ACC) requires adrenalectomy as first line therapy and adjuvant mitotane therapy; synchronous bilateral adrenalectomy (SBA) is useful for Cushing’s disease (only cases refractory to pituitary targeted therapy), for ectopic Cushing’s syndrome (cases with unknown or inoperable primary site), and for bilateral cortisol producing adenomas. The less established aspects are the following: criteria of skilled surgeon to approach ACC; the timing of surgery in subclinical CS; the need for adrenal vein catheterization (which is not available in many centers) to avoid unnecessary SBA.

Conclusion. Adrenalectomy for CS is a dynamic domain; LA overstepped the former OA area. The future will improve the knowledge related to RA while the cutting edge is represented by a specific frame of intervention in SCS, children and pregnant women.

Abbreviations: ACC = adrenocortical carcinoma, ACTH = Adrenocorticotropic Hormone, CD = Cushing’s disease, CS = Cushing’s syndrome, ECS = Ectopic Cushing’s syndrome, LA = laparoscopic adrenalectomy, OA = open adrenalectomy, PA = partial adrenalectomy, RA = robotic adrenalectomy, SCS = subclinical Cushing’ syndrome

Biochemical and clinical benefits of unilateral adrenalectomy in patients with subclinical hypercortisolism and bilateral adrenal incidentalomas

OBJECTIVE

The treatment of subclinical hypercortisolism in patients with bilateral adrenal incidentalomas (AI) is debatable. We aimed to compare the biochemical and clinical outcome of unilateral adrenalectomy vs a conservative approach in these patients.

DESIGN

Retrospective study.

METHODS

The study included 33 patients with bilateral AI; 14 patients underwent unilateral adrenalectomy of the largest lesion (surgical group), whereas 19 patients were followed up (follow-up group). At baseline and at each follow-up visit, we measured 0800 h plasma ACTH, midnight serum cortisol (MSF), 24-h urinary-free cortisol (UFC) and serum cortisol following a standard 2-day low-dose-dexamethasone-suppression test (LDDST). We evaluated the following comorbidities: arterial hypertension, impaired glucose tolerance or diabetes mellitus, dyslipidemia and osteoporosis.

RESULTS

Baseline demographic, clinical characteristics and the duration of follow-up (53.9±21.3 vs 51.8±20.1 months, for the surgical vs the follow-up group) were similar between groups. At the last follow-up visit the surgical group had a significant reduction in post-LDDST cortisol (2.4±1.6 vs 6.7±3.9 μg/dl, P=0.002), MSF (4.3±2 vs 8.8±4.6 μg/dl, P=0.006) and 24-h UFC (50.1±21.1 vs 117.9±42.4 μg/24 h, P=0.0007) and a significant rise in mean±s.d. morning plasma ACTH levels (22.2±9.6 vs 6.9±4.8 pg/ml, P=0.002). Improvement in co-morbidities was seen only in the surgical group, whereas no changes were noted in the follow-up group.

CONCLUSIONS

Our early results show that removal of the largest lesion offers significant improvement both to cortisol excess and its metabolic consequences, without the debilitating effects of bilateral adrenalectomy. A larger number of patients, as well as a longer follow-up, are required before drawing solid conclusions.

Lipid abnormalities in patients with adrenal incidentalomas: role of subclinical hypercortisolism and impaired glucose metabolism

BACKGROUND

Subclinical hypercortisolism (SH) has been associated with metabolic complications such as type 2 diabetes mellitus, obesity and dyslipidemia. Scarce data are available regarding the lipid pattern abnormalities in SH, in relation to insulin resistance and impaired glucose metabolism (IGM). We aimed to evaluate the possible influence of SH on lipid pattern in relation to the presence/absence of impaired glucose metabolism.

METHODS

In 338 patients with adrenal incidentaloma, the presence of SH, hypertension, dyslipidemia and IGM was evaluated. According to the presence of SH and IGM the patients were divided into 4 groups (IGM+SH+, IGM+SH-, IGM-SH+, IGM-SH-). We recruited 98 subjects without IGM (IGM-) and 100 with IGM (IGM+) as control groups.

RESULTS

The prevalence of dyslipidemia was comparable among Group IGM+SH+, Group IGM+SH- and IGM+ controls (57.9, 58.4, 56%, P = NS). No difference in dyslipidemia prevalence among IGM- patients and IGM- controls was observed. The IGM+SH+ patients had a higher prevalence of dyslipidemia (57.9%) than IGM-SH+ ones (29.1%, P < 0.01). The IGM+SH- patients showed an increased prevalence of hypertension (76.6 vs 54.8%, P < 0.01) and dyslipidemia (58.4 vs 23.8%, P < 0.0001) as compared with IGM-SH- patients. Logistic regression analysis showed that only IGM was associated to dyslipidemia (OR 4.31, 95% CI 2.61-7.12, P = 0.0001) regardless of age, SH and gender.

CONCLUSIONS

In the absence of alterations of glucose metabolism the presence of a subtle cortisol excess has no effect on lipid pattern. IGM seems to influence the lipid metabolism regardless of the presence of SH.

Screening for ACTH-dependent hypercortisolism in patients affected with pituitary incidentaloma

CONTEXT

Pituitary incidentalomas (PIs) are commonly encountered in clinical practice. The management of these asymptomatic pituitary lesions is still controversial. Systematic screening for subclinical or mild ACTH-dependent hypercortisolism (AH) is not presently recommended, due to the limited data available thus far on the epidemiological and clinical relevance of this condition in patients with PIs. As subclinical hypercortisolism (SH) was considered to be associated with chronic complications of overt cortisol excess, such as hypertension, diabetes, and osteoporosis, this disorder should be diagnosed at the early stage.

OBJECTIVE

The objective of this study was to evaluate the prevalence of hypercortisolism in a population of subjects with PIs.

DESIGN, SUBJECTS, AND METHODS

A total of 68 consecutive patients (48 females and 20 males, aged 18-82 years) without clinically overt hypercortisolism, who were referred for evaluation of PIs between January 2010 and March 2013, were prospectively investigated for AH. Pituitary hypercortisolism was diagnosed in the presence of cortisol >50 nmol/l after 1 mg dexamethasone suppression test, non-suppressed ACTH, and the additional finding of one of the following: urinary free cortisol (UFC) >193 nmol/24 h, and midnight serum and salivary cortisol levels >207 and 2.8 nmol/l respectively.

RESULTS

Among patients with PIs, we found a 7.3% rate of pituitary hypercortisolism diagnosed with biochemical criteria and a 4.4% rate of histologically confirmed AH.

CONCLUSIONS

Subclinical or mild hypercortisolism may be more common than generally perceived in patients with PIs.

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.

Clinical Characteristics and Metabolic Features of Patients with Adrenal Incidentalomas with or without Subclinical Cushing's Syndrome

BACKGROUND

The aim of this study was to examine the clinical characteristics of adrenal incidentalomas discovered by computed tomography (CT) and to investigate metabolic features of subclinical Cushing's syndrome (SCS) in patients with adrenal incidentalomas in a tertiary hospital in Korea.

METHODS

This retrospective study examined the clinical aspects of 268 patients with adrenal incidentalomas discovered by CT at Soonchunhyang University Bucheon Hospital. Clinical data and endocrine function of the patients as well as histological findings were obtained from medical records, while anatomic characteristics were analyzed by reviewing imaging studies. Hormonal tests for pheochromocytoma, Cushing's syndrome, and aldosterone-secreting adenoma were performed.

RESULTS

Most (n=218, 81.3%) cases were nonfunctioning tumors. Of the 50 patients with functioning tumors (18.7%), 19 (7.1%) were diagnosed with SCS, nine (3.4%) with overt Cushing's syndrome, 12 (4.5%) with primary aldosteronism, and 10 (3.7%) with pheochromocytoma. Malignant tumors (both primary and metastatic) were rare (n=2, 0.7%). Body mass index, fasting glucose, hemoglobin A1c, and total cholesterol were significantly higher in patients with SCS in comparison with those with nonfunctioning tumors. The prevalence of type 2 diabetes mellitus and hypertension were significantly higher in patients with SCS compared with those with nonfunctioning tumors.

CONCLUSION

Functioning tumors, especially those with subclinical cortisol excess, are commonly found in patients with adrenal incidentalomas, although malignancy is rare. In addition, patients with SCS in adrenal incidentalomas have adverse metabolic and cardiovascular profiles.

Persistent Comorbidities in Cushing’s Syndrome after Endocrine Cure

It was assumed that resolution of hypercortisolism in Cushing syndrome (CS) was followed by normalization of morbidity; however, in the last decade evidence is accumulating that patients with cured CS still have increased morbidity and mortality after the biochemical control of hypercortisolism. Patients with CS have an increased cardiovascular and metabolic risk and persistent accumulation of central fat, with an unfavorable adipokine profile, not only during the active phase of the disease but also long after biochemical remission. Clinical management should be particularly careful in identifying global cardiovascular risk, as a primary goal during the followup of these patients, aimed at improving global vascular morbidity. Moreover bone mass is reduced not only due to the endogenous hypercortisolism but also due to duration and dose of exogenous glucocorticoid (GC) replacement therapy after surgery. Thus, therapy in operated patients with inhibition of the hypothalamic-pituitary-adrenal axis should be reduced to the lowest dose and duration possible. Specific treatments should be considered in patients with decreased bone mass, aimed at reducing the increased fracture incidence. Finally, cognitive and health related quality of life impairments, described in active disease, are still abnormal after endocrine cure. Thus, residual morbidity persists in cured CS, suggesting irreversibility of GC-induced phenomena, typical of chronic hypercortisolism.

Somatic mutations of the catalytic subunit of cyclic AMP-dependent protein kinase (PRKACA) gene in Japanese patients with several adrenal adenomas secreting cortisol [Rapid Communication]

Somatic mutations of the catalytic subunit of the cyclic AMP-dependent protein kinase (PRKACA) gene have recently been identified in about 35% of cortisol-producing adenomas (CPAs), with the affected patients showing overt Cushing's syndrome. Since we recently reported higher prevalence of mutations of the KCNJ5 gene and associations with autonomous cortisol secretion in Japanese aldosterone-producing adenomas than in Western countries, there might be different features of CPAs between Japan and the West. We therefore investigated mutations of the PRKACA gene in Japanese patients with several adrenal tumors secreting cortisol, including overt Cushing's syndrome, subclinical Cushing's syndrome, and aldosterone-producing adenomas (APAs) co-secreting cortisol operated on at Gunma University Hospital. Of the 13 patients with CPA who showed overt Cushing's syndrome, 3 (23%) had recurrent somatic mutations of the PRKACA gene, p.L206R (c.617 T>G), and there were no mutations in subclinical Cushing's syndrome. Among 33 APAs, 24 had somatic mutations of the KCNJ5 gene, either G151R or L168R, 11 (33%) had autonomous cortisol secretion, but there were no mutations of the PRKACA gene. We established a PCR-restriction fragment length polymorphism assay and revealed that the mutated allele was expressed at a similar level to the wild-type allele. These findings demonstrated that 1) the prevalence of Japanese patients with CPA who showed overt Cushing's syndrome and whose somatic mutations in the PRKACA gene was similar to that in Western countries, 2) the mutation might be specific for CPAs causing overt Cushing's syndrome, and 3) the mutant PRKACA allele was expressed appropriately in CPAs.

Adrenal incidentaloma imaging - the first steps in therapeutic management

The term “adrenal incidentaloma” refers to clinically unapparent adrenal mass detected during imaging examination performed for reasons other than the evaluation of adrenal glands. These tumors must be carefully examined in order to assess the indications for surgical treatment. The main method of finding evidence of potential malignancy in these lesions is computed tomography (CT), before and after i.v. contrast media enhancement. Density of a malignant lesion is higher than 10 HU and the relative percentage washout is less than 40% at 10 min. Other useful methods utilized in tumor assessment, include magnetic resonance imaging (MRI), scintigraphy techniques (SPECT) and PET. Basal hormonal investigations include urine and plasma catecholamines with their metabolites, plasma cortisol before and after dexamethasone administration, plasma renin activity and aldosterone level. Cases not suitable for surgery should be followed with repeat imaging techniques and hormonal testing at the recommended 6, 12, and 24 months. Surgery should be performed when tumor growth rate exceeds 0,8 cm per year.

Acute administration of alprazolam, a benzodiazepine activating GABA receptors, inhibits cortisol secretion in patients with subclinical but not overt Cushing's syndrome

The purpose of this study is to verify whether acute pre-treatment with alprazolam (ALP), a benzodiazepine that inhibits HPA secretion in normal subjects, could better characterize patients with subclinical Cushing's syndrome (SCS) than the 1-mg dexamethasone test (DST). In 22 patients with SCS, 10 with overt Cushing's syndrome (CS), 11 with non-functioning adrenal incidentalomas (NF) and 14 normal subjects (NS) we studied the effect of ALP (1 mg, p.o. at 2300 hours) on cortisol levels after 1-mg DST. Cortisol levels (mean ± SEM) after DST were lower (P = 0.012) in SCS (3.9 ± 0.3 μg/dl) than in overt CS (10.4 ± 1.9 μg/dl), while they were higher (P = 0.0005) than in NF (1.1 ± 0.1 μg/dl) and NS (1.5 ± 0.1 μg/dl). After ALP pre-treatment, cortisol levels further decreased (P = 0.004) in SCS (3.0 ± 0.3 μg/dl), but neither in CS (9.3 ± 1.3 μg/dl) nor in NF (1.3 ± 0.1 μg/dl) and in NS (1.3 ± 0.1 μg/dl). In SCS, cortisol levels after ALP + 1-mg DST persisted lower (P = 0.0005) than those in CS, but higher (P = 0.0005) than those in NF and NS. Considering individual cases, ALP pre-treatment reduced cortisol levels < 3 and < 1.8 μg/dl in 50 and 23 % of SCS patients, respectively. ALP amplifies the cortisol inhibition exerted by 1-mg DST in patients with SCS but not in those with CS. The clinical usefulness of ALP to increase the sensitivity of 1-mg DST to identify true autonomous cortisol release in patients with adrenal incidentalomas as well as to predict different clinical outcomes remains to be clarified.

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

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

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.

Bilateral and unilateral adrenal incidentalomas: biochemical and clinical characteristics

OBJECTIVE

The possible different prevalence of arterial hypertension (AH), type 2 diabetes mellitus (T2DM), dyslipidaemia (DL) and vertebral fractures (FX) between patients with bilateral and unilateral adrenal incidentalomas (BAI and UAI, respectively) with and without subclinical hypercortisolism (SH) is unknown. In this study we compared the prevalence of AH, T2DM, DL and FX in BAI and UAI patients in relation to SH.

DESIGN

Prospective study.

METHODS

In 175 UAI and 38 BAI patients, we evaluated BMI, spinal and femoral bone mineral density (LS and FN BMD, respectively) and the presence of AH, T2DM, DL and FX. SH was diagnosed in the presence of 2 of the following: urinary free cortisol levels >193 nmol/24 h, serum cortisol levels after 1 mg dexamethasone suppression test >83 nmol/l or ACTH levels <2.2 pmol/l.

RESULTS

Age, BMI and cortisol secretion were comparable, while FN BMD was lower in BAI than in UAI patients (-0.45±0.86 vs 0.09±1.07, P=0.004). The prevalence of SH, AH, T2DM, and DL was comparable, while the prevalence of FX was higher in BAI than in UAI (52.6 vs 28%, P=0.007). The presence of FX was associated with BAI (odds ratio (OR) 2.6, 95% confidence interval (95% CI) 1.2-5.6, P=0.016), after adjusting for SH (OR 1.77, 95% CI 0.85-3.7, P=0.12), BMI (OR 1.06, 95% CI 0.98-1.13, P=0.1), age (OR 1.07, 95% CI 1.04-1.11, P=0.0001) and LS BMD (OR 1.31, 95% CI 1.03-1.67, P=0.03).

CONCLUSION

BAI patients have an increased FX risk than UAI ones. Further studies should investigate the causes of bone involvement in BAI patients.

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.

Laparoscopic adrenalectomy for co-secreting aldosterone and cortisol adenomas

There are few published data on aldosterone and cortisol co-secreting adrenal tumours. Failure to perform comprehensive preoperative endocrine investigations in patients with adrenal "incidentalomas" or in those thought to be secreting only one hormone may account for this. Clinically patients with such lesions may have evidence of hypertension and hypokalaemia with no features of cortisol excess. Preoperative diagnosis of such lesions with accurate endocrinological work up is essential to prevent adrenal insufficiency and haemodynamic crises following removal of such glands. We present a series of 4 patients with co-secreting tumours treated by laparoscopic adrenalectomy between September 2010 and March 2011. Our experience suggests that dual secretors are more common than originally thought. A high index of suspicion and adequate endocrine work up is paramount in diagnosing such tumours and in experienced hands, laparoscopic adrenalectomy with appropriate substitutive steroid cover is safe, feasible and curative for these functioning adrenal tumours.

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.

Subclinical hypercortisolism and CT appearance in adrenal incidentalomas: a multicenter study from Southern Sweden

Evaluation of subclinical hypercortisolism (SH) in patients with adrenal incidentaloma (AI) including its correlation to size, attenuation at unenhanced computed tomography (CT) and unilateral or bilateral adrenal disease. Nine hospitals in Southern Sweden investigated during 2005-2007 consecutively patients with AI with hormonal and CT examinations according a regional protocol. Two hundred and twenty-eight patients with AI with median size 2.0 cm were included. One mg overnight dexamethasone suppression test (DST) was performed in 223 patients and basal P-ACTH measured in 146 patients. SH was defined as cortisol ≥ 50 nmol/l at DST in combination with basal ACTH <2 pmol/l. In patients with unilateral AI 42% (76/180) had inadequate suppression at DST and 23% (27/115) had SH. The probability for SH and inadequate suppression at DST correlated positively to size and inversely to attenuation at CT. Bilateral AI were found in 43 patients and of these 70% (30/43) had inadequate suppression at DST and 42% (13/31) SH. The patients with SH or inadequate suppression at DST had increased frequency of hypertension which increased further in patients with post-DST cortisol ≥ 140 nmol/l. The applied criterion for SH is useful for initial evaluation of patients with AI. SH is common in patients with AI, particular in bilateral disease. In patients with unilateral AI the probability for SH correlated positively to size and inversely to attenuation at CT. Furthermore, SH and the post-DST cortisol concentration was associated with hypertension.

Glucose metabolism in patients with subclinical Cushing's syndrome

This clinical review will summarize the available data regarding the effect of either physiological or increased glucocorticoid concentrations on glucose metabolism and insulin-sensitivity, in order to clarify the role, if any, of subclinical Cushing's syndrome (SCS), a status of altered hypothalamic-pituitary-adrenal axis secretion in the absence of the classical signs or symptoms of overt cortisol excess, in patients with adrenal incidentalomas (AI) and diabetes mellitus type 2. Focusing on patients with SCS associated to AI, while there is convincing evidence in the literature that even a mild hyper cortisolemia is associated with alterations of glucose metabolism, evidence is insufficient to conclude that the simple correction of chronic, even mild, hypercortisolism can completely revert metabolic, mainly glycemic alterations. At the same time, considering the variability of the prevalence of Cushing's syndrome in patients with diabetes mellitus type 2 reported in the literature, no agreement does exist whether screening for CS can be useful and recommended in those patients.

KCNJ5 mutations in aldosterone- and cortisol-co-secreting adrenal adenomas

Adrenal aldosterone-producing adenomas (APA) are rarely associated with the clear co-secretion of cortisol. Somatic mutations of the potassium channel KCNJ5 gene, with the hotspots G151R and L168R, have been recently identified in patients with APA. However, whether APAs that secrete cortisol have these mutations remains unclear. We examined three patients with APAs showing clear autonomous secretion of cortisol who possessed a 1 mg dexamethasone suppression test (DST) with a failure of the serum cortisol level to drop below 3.0 μg/dL, a morning plasma ACTH level of less than 10 pg/mL, and suppressed accumulation in the intact adrenal on (131)I- adosterol scintigraphy, or postoperative adrenal insufficiency. Laparoscopic adrenectomy revealed all tumors to be golden yellow, and histological examination confirmed them to be adrenocortical adenomas. All these patients required replacement therapy with hydrocortisone after surgery. Sequencing demonstrated that 2 of three cases showed a mutation of the KCNJ5 gene, one with c.451G>A, p.G151R and one with c.503T>G, p.L168R. Furthermore, the mRNA levels of steroidogenic enzymes including CYP11B1, CYP11B2, HSD3B2, CYP17A1, CYP11A1 and KCNJ5 in the 3 cases did not differ from those in 8 pure APAs not showing any of the above conditions for autonomous cortisol secretion. In addition, all 8 pure APAs harbored mutations of the KCNJ5 gene. These findings suggested that at least some aldosterone- and cortisol-co-secreting adrenal tumors have mutations of the KCNJ5 gene, suggesting the origin to be APA, and pure APAs may show a high incidence of KCNJ5 mutations.

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.

Metabolic and cardiovascular outcomes in patients with Cushing's syndrome of different aetiologies during active disease and 1 year after remission

OBJECTIVE

Cushing's syndrome is associated with several comorbidities responsible for the increased cardiovascular risk, not only during the active phase but also after disease remission.

DESIGN

In 29 patients with Cushing's syndrome (14 Cushing's diseases and 15 adrenal adenomas), waist circumference, fasting and 2-h glucose after oral glucose tolerance test (OGTT), lipid profile and blood pressure were evaluated during the active disease and 1 year after remission and compared with those in 29 sex-, age- and BMI-matched controls.

RESULTS

During the active disease, waist circumference, 2-h glucose after OGTT, total and LDL cholesterol were higher in patients with Cushing's syndrome than in controls (P < 0·001) but similar in Cushing's disease and adrenal adenomas. The prevalence of impaired glucose tolerance (IGT), diabetes mellitus, dyslipidaemia and hypertension was higher (P < 0·001) in patients with Cushing's syndrome (27%, 24%, 59% and 72%) than in controls (10%, 0%, 21% and 10%), with no significant difference between Cushing's disease and adrenal adenomas. One year following hormonal remission, waist circumference persisted higher than in controls (P < 0·05) in both Cushing's disease and adrenal adenomas. Metabolic and cardiovascular abnormalities were still present in both groups, although with a lower prevalence, as well as with a more marked decrease in adrenal adenomas (P < 0·05 vs active disease for IGT, dyslipidaemia and hypertension).

CONCLUSIONS

These results show that chronic hypercortisolism, independently of its aetiology, contributes to metabolic impairment and increased cardiovascular risk, while these abnormalities mostly persist in patients with previous Cushing's disease after hormonal remission. Pituitary hormonal deficiencies, hormonal replacement treatments and/or incomplete cure from Cushing's disease may account for these findings.

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.

The clinical significance of adrenal incidentalomas

BACKGROUND

The term adrenal incidentaloma (AI) indicates an adrenal mass lesion > 1 cm in diameter discovered during testing for conditions unrelated to adrenal disease. The overall prevalence of these lesions ranges between 3% and 10%. Their incidence increases with age, and it is clinically important to identify AI associated with hormonal activity and/or malignant potential.

DESIGN

A detailed Medline search of all English language articles related to AI was carried out, and the clinical implications related to their hormonal activity and malignant potential are discussed.

RESULTS

The subclinical hypercortisolism observed in a significant percentage of patients with AI is associated with some of the detrimental effects of continuous autonomous cortisol secretion, including a higher prevalence of hypertension, dyslipidaemia, impaired glucose tolerance or type 2 diabetes mellitus and an increased risk for osteoporotic fractures. However, it remains to be proven whether treatment to reverse subtle glucocorticoid excess is beneficial. Clinically silent phaeochromocytomas and primary adrenal cancer are conditions associated with significantly high morbidity and mortality and require urgent treatment, while the prevalence and clinical significance of autonomous mineralocorticoid secretion are less clearly defined. Size and radiological features are the main predictors of malignant potential.

CONCLUSIONS

Patients harbouring AI should be evaluated for the possibility of malignancy and/or subclinical hypercortisolism which is associated with cardiovascular risk and bone loss. However, in the absence of prospective controlled studies correlating biochemical activity with end-organ complications, the long-term consequences of AI remain uncertain and their management remains largely pragmatic.

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.

The size of adrenal incidentalomas correlates with insulin resistance. Is there a cause-effect relationship?

CONTEXT

Adrenal incidentalomas (AI) have often been associated with a high prevalence of insulin resistance (IR) and cardiovascular risk factors, although direct measurement of insulin sensitivity (IS) has never been carried out.

OBJECTIVE

We aimed to investigate whether the morphological and hormonal features of AI correlate with the presence and severity of IR, using the hyperinsulinaemic euglycaemic clamp (HEC).

DESIGN AND MEASUREMENTS

Forty patients with AI (22 women) with a mean age of 58.5±11.1 years underwent hormonal and morphological evaluation. Nineteen patients with AI without known history of diabetes mellitus (DM) or impaired glucose tolerance (IGT) and 17 matched controls underwent oral glucose tolerance test (OGTT) and hyperinsulinaemic euglycaemic clamp (HEC).

RESULTS

Diabetes mellitus was observed in 13 patients (33%), while three (8%) had IGT. Thirty-one of the AI were nonfunctioning (82.5%), whereas two (5%) secreted cortisol (Cushing's syndrome) and seven (12.5%) showed subclinical secretion of cortisol. The 19 patients with nonfunctioning AI were more insulin resistant than controls (glucose up-take: 4.58±1.80 vs 5.85±2.48 mg/kg/min respectively; P=0.01); IS was inversely related to the mass size (r=-0.57; P=0.04), free urinary cortisol (r=-0.68; P=0.01), serum cortisol after 1-mg dexamethasone suppression (-0.65; P=0.02) and percentage of trunk fat mass (-0.77; P=0.02) and directly related to serum adreno cortico tropic hormone (ACTH) (r=0.62; P=0.03). After performing multivariate regression, the mass size was found to be the most powerful predictor of IR.

CONCLUSION

Our study showed a high prevalence of insulin resistance in patients with nonfunctioning AI and suggests its possible involvement in AI growth.

Pros and cons of dexamethasone suppression test for screening of subclinical Cushing's syndrome in patients with adrenal incidentalomas

The results of dexamethasone suppression tests (DST) in the screening of subclinical hypercortisolism are not readily comparable. Aim of the present study was to review the effectiveness of overnight 1-mg DST and 8-mg DST to look for functional autonomy of clinically inapparent adrenal adenomas. Sixty-eight consecutive patients with clinically inapparent adrenal adenomas were enrolled. All patients underwent 1-mg DST. The 8-mg DST was performed in the 11 patients who had post 1-mg DST cortisol >138 nmol/l and in 11 patients who had post 1-mg DST cortisol between 50 and 138 nmol/l. The a priori probability to have autonomous cortisol secretion was defined by the presence of at least two alterations of the hypothalamic-pituitary-adrenal axis among reduced ACTH concentrations, elevated urinary free cortisol (UFC) or elevated midnight serum cortisol. Cortisol levels >138 nmol/l after the 1-mg DST increases the post-test probability of adrenal functional autonomy to 55%, whereas cortisol levels <50 nmol/l reduce the post-test probability to 8%. Cortisol levels recorded after the 8-mg DST were nonsignificantly lower than after the 1-mg DST and all the patients with cortisol >138 nmol/l after the 1-mg DST maintained cortisol above this cut-point. The 1-mg DST should be considered as the more effective test to detect autonomous cortisol secretion by a clinically inapparent adrenal adenoma when cortisol levels are >138 nmol/l, while cortisol levels <50 nmol/l reduce remarkably the post-test probability of this event. The 8-mg DST seems to replicate by large the results of the 1-mg DST.

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.

Adrenal incidentalomas and cardiometabolic morbidity: an emerging association with serious clinical implications

Adrenal incidentalomas (AIs) represent adrenal masses that are incidentally discovered whilst investigating symptoms and signs unrelated to adrenal pathology. The onset and natural course of AIs are unknown, and the possible underlying cardiometabolic abnormalities have not been examined in depth. A growing body of clinical and experimental evidence supports the notion that both functioning and, paradoxically, nonfunctioning AIs are associated with a partially expressed or even full-blown metabolic syndrome (MS) phenotype, through yet unclear mechanisms. Subtle, subclinical or even profound adrenal hormone excess and an increased proinflammatory state might explain to some extent the development of MS disturbances. The emerging association between AIs and MS appears to be important in determining the optimal clinical management of these patients and raises speculation about the exact mechanisms of this interesting cause-effect relationship.

Insulin resistance and metabolic syndrome in patients with nonfunctioning adrenal incidentalomas: a cause-effect relationship?

The objective of the study was to assess insulin resistance (IR) and metabolic syndrome (MS) in patients with nonfunctioning adrenal incidentalomas (NFAIs). Among a total cohort of 46 patients with adrenal incidentalomas, we studied 29 patients with NFAIs (mean age, 54 ± 9 years; body mass index, 29 ± 3 kg/m(2)) and 37 age-, sex-, and body mass index-matched healthy controls. Besides the endocrine workup, IR was evaluated using fasting glucose and insulin concentrations, homeostasis model assessment of IR, and quantitative insulin sensitivity check index. In a subgroup of patients undergoing an oral glucose tolerance test, Matsuda index and total area under the curve for glucose and insulin were also evaluated. Total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, and other biochemical parameters were measured with standard techniques. Body composition was determined with dual-energy x-ray absorptiometry. Patients with NFAIs exhibited higher fasting glucose, insulin, and homeostasis model assessment of IR values; decreased quantitative insulin sensitivity check index and Matsuda index; and an increased-although not statistically significant-area under the curve for glucose and insulin compared with controls (P < .05). In addition, they exhibited higher systolic and diastolic blood pressure, triglycerides, and γ-glutamyltransferase and lower high-density lipoprotein cholesterol levels compared with controls (P < .05). Patients with NFAIs were all obese with a central type of fat accumulation and increased appendicular lean mass. Indices of IR showed a positive correlation with indices of MS (P < .05), but no correlation with markers of hormonal activity. Nonfunctioning adrenal incidentalomas are characterized by IR, hypertension, dyslipidemia, and fatty liver disease, all of them being components of MS. Thus, patients with NFAIs should be screened for MS during their initial workup to identify those at cardiometabolic risk and implement the appropriate interventions.

Role of glucocorticoid receptor polymorphism in adrenal incidentalomas

BACKGROUND

Adrenal incidentalomas (AI) have been associated with and an increased prevalence of metabolic and bone complications. The N363S and BclI polymorphisms of the glucocorticoid receptor (GR) have been associated with an increased sensitivity to glucocorticoid (GC). This observational study aims to evaluate whether BclI and N363S polymorphisms play a role in the development of complications in AI.

MATERIALS AND METHODS

We enrolled 100 patients with AI (66 F; 34M). The presence of diabetes, arterial hypertension (AH), dyslipidaemia, osteoporosis and vertebral fracture (Fx), waist circumference and the Body Mass Index (BMI) were assessed. DNA samples were genotyped. Patients with wild-type BclI, wild-type N363S and heterozygous BclI polymorphism were classified as carriers of haplotype 1 (H1; n = 86), patients with homozygous BclI and heterozygous N363S polymorphism of GR of haplotype 2 (H2; n = 14).

RESULTS

We found no clinical or biochemical differences between haplotype 1 and 2 groups, but a higher prevalence of the simultaneous presence of Fx plus AH in H2 patients (H2 n = 7, H1 n = 16, P = 0.01). Logistic regression analysis showed that the presence of Fx and of AH and the combination of the presence of Fx plus AH were associated with the H2 genotype regardless of the degree of cortisol secretion, age, BMI and BMD (OR 4.88, 95%CI 1.47-18.40, P = 0.05; OR 8.25, 95%CI 0.98-69.52, P = 0.05; OR 7.25, 95%CI 1.57-35.78, P = 0.011; respectively).

CONCLUSIONS

In AI patients, the presence of the haplotype 2 of BclI and N363S is associated with the presence of AH, Fx and with the combination of Fx and AH.

Beneficial metabolic effects of prompt surgical treatment in patients with an adrenal incidentaloma causing biochemical hypercortisolism

CONTEXT

In patients with adrenal incidentalomas, subclinical hypercortisolism (SH) is associated with an increased prevalence of the metabolic syndrome. The effect of surgical/conservative approach is debated.

OBJECTIVE

The objective of the study was to determine the effect of the surgical and conservative approaches on the metabolic syndrome in patients with adrenal incidentalomas.

DESIGN

This was a retrospective longitudinal study (18-48 months follow-up).

SETTING

The study was conducted on an in- and outpatient basis.

PATIENTS

One hundred eight patients with adrenal incidentalomas were studied for the presence of SH, which was diagnosed in the presence of more than two of the following: urinary free cortisol greater than 70 microg per 24 h (193 nmol per 24 h), cortisol after 1 mg dexamethasone suppression test greater than 3.0 microg/dl (83 nmol/liter), ACTH less than 10 pg/ml (2.2 pmol/liter).

INTERVENTIONS

Surgery was performed in 25 patients with SH (group TrSH+) and 30 without SH (group TrSH-), whereas the conservative approach was chosen by 16 patients with SH (group UntrSH+) and 37 without SH (group UntrSH-).

MAIN OUTCOME MEASURES

During the follow-up, the improvement/worsening of body weight, blood pressure, or glucose and cholesterol levels was defined in the presence of a greater than 5% weight decrease/increase and following the European Society of Cardiology or the Adult Treatment Panel III criteria, respectively.

RESULTS

In group TrSH+, weight, blood pressure, and glucose levels improved (32, 56, and 48%, respectively) more frequently than in group UntrSH+ (12.5%, P = 0.05; 0.0%, P < 0.0001; 0.0%, P = 0.001; and 0.0%, P = 0.0014, respectively). In group UntrSH+, blood pressure, glucose, and low-density lipoprotein levels worsened more frequently (50.0, 37.5, and 50.0%, respectively) than in group TrSH+ (0.0%, P < 0.0001; 0.0%, P = 0.001; and 20.0%, P = 0.05, respectively).

CONCLUSIONS

Regarding the various components of the metabolic syndrome, in patients with adrenal incidentalomas and SH, surgery is beneficial.