Autonomous hypercortisolism: definition and clinical implications

Are comorbidities of patients with adrenal incidentaloma tied to sex?

Background

A recent cross-sectional study showed that both comorbidities and mortality in patients with adrenal incidentaloma (AI) are tied to sex. However, few longitudinal studies evaluated the development of arterial hypertension, hyperglycemia, dyslipidemia and bone impairment in patients with AI. The aim of this study is to analyze the impact of sex in the development of these comorbidities during long-term follow-up.

Methods

We retrospectively evaluated 189 patients (120 females, 69 males) with AI, from four referral centers in Italy and Croatia. Clinical characteristics, comorbidities and cortisol after 1-mg dexamethasone suppression test (1-mg DST) were assessed at baseline and at last follow-up visit (LFUV). Median follow-up was 52 (Interquartile Range 25-86) months.

Results

The rates of arterial hypertension and hyperglycemia increased over time both in females (65.8% at baseline versus 77.8% at LFUV, p=0.002; 23.7% at baseline versus 39.6% at LFUV, p<0.001; respectively) and males (58.0% at baseline versus 69.1% at LFUV, p=0.035; 33.8% at baseline versus 54.0% at LFUV, p<0.001; respectively). Patients were stratified in two groups using 1.8 µg/dl as cut-off of cortisol following 1-mg DST: non-functional adrenal tumors (NFAT) and tumors with mild autonomous cortisol secretion (MACS). In the NFAT group (99 patients, females 62.6%), at baseline, we did not observe any difference in clinical characteristics and comorbidities between males and females. At LFUV, males showed a higher frequency of hyperglycemia than females (57.6% versus 33.9%, p=0.03). In the MACS group (89 patients, females 64.0%), at baseline, the prevalence of hypertension, hyperglycemia and dyslipidemia was similar between sexes, despite females were younger (60, IQR 55-69 versus 67.5, IQR 61-73, years; p=0.01). Moreover, females presented higher rates of bone impairment (89.3% versus 54.5%, p=0.02) than males. At LFUV, a similar sex-related pattern was observed.

Conclusion

Patients with AI frequently develop arterial hypertension and hyperglycemia and should be periodically checked for these comorbidities, regardless of sex. In patients with MACS, the lack of difference between sexes in the frequency of cardiometabolic comorbidities despite that females are younger, and the higher frequency of bone impairment in females, suggest a sex-specific effect of cortisol.

Emerging diagnostic methods and imaging modalities in cushing's syndrome

Endogenous Cushing's syndrome (CS) is a rare disease characterized by prolonged glucocorticoid excess. Timely diagnosis is critical to allow prompt treatment and limit long-term disease morbidity and risk for mortality. Traditional biochemical diagnostic modalities each have limitations and sensitivities and specificities that vary significantly with diagnostic cutoff values. Biochemical evaluation is particularly complex in patients whose hypercortisolemia fluctuates daily, often requiring repetition of tests to confirm or exclude disease, and when delineating CS from physiologic, nonneoplastic states of hypercortisolism. Lastly, traditional pituitary MRI may be negative in up to 60% of patients with adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (termed "Cushing's disease" [CD]) whereas false positive pituitary MRI findings may exist in patients with ectopic ACTH secretion. Thus, differentiating CD from ectopic ACTH secretion may necessitate dynamic testing or even invasive procedures such as bilateral inferior petrosal sinus sampling. Newer methods may relieve some of the diagnostic uncertainty in CS, providing a more definitive diagnosis prior to subjecting patients to additional imaging or invasive procedures. For example, a novel method of cortisol measurement in patients with CS is scalp hair analysis, a non-invasive method yielding cortisol and cortisone values representing long-term glucocorticoid exposure of the past months. Hair cortisol and cortisone have both shown to differentiate between CS patients and controls with a high sensitivity and specificity. Moreover, advances in imaging techniques may enhance detection of ACTH-secreting pituitary adenomas. While conventional pituitary MRI may fail to identify microadenomas in patients with CD, high-resolution 3T-MRI with 3D-spoiled gradient-echo sequence has thinner sections and superior soft-tissue contrast that can detect adenomas as small as 2 mm. Similarly, functional imaging may improve the identification of ACTH-secreting adenomas noninvasively; Gallium-68-tagged corticotropin-releasing hormone (CRH) combined with PET-CT can be used to detect CRH receptors, which are upregulated on corticotroph adenomas. This technique can delineate functionality of adenomas in patients with CD from patients with ectopic ACTH secretion and false positive pituitary lesions on MRI. Here, we review emerging methods and imaging modalities for the diagnosis of CS, discussing their diagnostic accuracy, strengths and limitations, and applicability to clinical practice.

Limited Role of Hair Cortisol and Cortisone Measurement for Detecting Cortisol Autonomy in Patients With Adrenal Incidentalomas

Several studies demonstrated the diagnostic accuracy of hair glucocorticoid measurement in patients with overt Cushing syndrome, but few data are available for patients with adrenal incidentaloma (AI) and cortisol autonomy. The aim of our study was to assess whether measurement of 5 corticosteroid hormones with the ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method in the keratin matrix is useful to stratify patients with AI by the presence of autonomous cortisol secretion [ACS] (defined as serum cortisol after 1 mg dexamethasone suppression test (DST) > 138 nmol/l) or possible ACS [PACS] (defined as serum cortisol after 1 mg DST > 50 nmol/l but ≤138 nmol/l). We analysed data of 67 AI patients (32 with cortisol autonomy) and 81 healthy subjects. We did not find any significant statistical difference comparing hair cortisol, cortisone, and 20β-dihydrocortisol concentrations between healthy controls and AI patients, while 6β-hydroxycortisol and 11-deoxycortisol were undetectable. Moreover, no significant difference was found in hair cortisol, cortisone, and 20β-dihydrocortisol levels of AI patients with or without cortisol autonomy. Finally, we did not find any correlation in patients with AI between hormonal concentrations in the keratin matrix and serum, salivary, and urinary cortisol levels, or with body mass index. In conclusion, our findings suggest that hair glucocorticoid measurement is not suitable as a diagnostic test for cortisol autonomy (ACS and PACS).

Targeting Nrf2-Mediated Oxidative Stress Response Signaling Pathways as New Therapeutic Strategy for Pituitary Adenomas

Oxidative stress and oxidative damage are the common pathophysiological characteristics in pituitary adenomas (PAs), which have been confirmed with many omics studies in PA tissues and cell/animal experimental studies. Nuclear factor erythroid 2 p45-related factor 2 (Nrf2), the core of oxidative stress response, is an oxidative stress sensor. Nrf2 is synthesized and regulated by multiple factors, including Keap1, ERK1/2, ERK5, JNK1/2, p38 MAPK, PKC, PI3K/AKT, and ER stress, in the cytoplasm. Under the oxidative stress status, Nrf2 quickly translocates from cytoplasm into the nucleus and binds to antioxidant response element /electrophile responsive element to initiate the expressions of antioxidant genes, phases I and II metabolizing enzymes, phase III detoxifying genes, chaperone/stress response genes, and ubiquitination/proteasomal degradation proteins. Many Nrf2 or Keap1 inhibitors have been reported as potential anticancer agents for different cancers. However, Nrf2 inhibitors have not been studied as potential anticancer agents for PAs. We recommend the emphasis on in-depth studies of Nrf2 signaling and potential therapeutic agents targeting Nrf2 signaling pathways as new therapeutic strategies for PAs. Also, the use of Nrf2 inhibitors targeting Nrf2 signaling in combination with ERK inhibitors plus p38 activators or JNK activators targeting MAPK signaling pathways, or drugs targeting mitochondrial dysfunction pathway might produce better anti-tumor effects on PAs. This perspective article reviews the advances in oxidative stress and Nrf2-mediated oxidative stress response signaling pathways in pituitary tumorigenesis, and the potential of targeting Nrf2 signaling pathways as a new therapeutic strategy for PAs.

Synacthen Stimulation Test Following Unilateral Adrenalectomy Needs to Be Interpreted With Caution

BACKGROUND

Cortisol levels in response to stress are highly variable. Baseline and stimulated cortisol levels are commonly used to determine adrenal function following unilateral adrenalectomy. We report the results of synacthen stimulation testing following unilateral adrenalectomy in a tertiary referral center.

METHODS

Data were collected retrospectively for 36 patients who underwent synacthen stimulation testing one day post unilateral adrenalectomy. None of the patients had clinical signs of hypercortisolism preoperatively. No patient received pre- or intraoperative steroids. Patients with overt Cushing's syndrome were excluded.

RESULTS

The median age was 58 (31-79) years. Preoperatively, 16 (44%) patients had a diagnosis of pheochromocytoma, 12 (33%) patients had primary aldosteronism and 8 (22%) patients had non-functioning adenomas with indeterminate/atypical imaging characteristics necessitating surgery. Preoperative overnight dexamethasone suppression test results revealed that 6 of 29 patients failed to suppress cortisol to <50 nmol/L. Twenty (56%) patients achieved a stimulated cortisol ≥450 nmol/L at 30 minutes and 28 (78%) at 60 minutes. None of the patients developed clinical adrenal insufficiency necessitating steroid replacement.

CONCLUSIONS

Synacthen stimulation testing following unilateral adrenalectomy using standard stimulated cortisol cut-off values would wrongly label many patients adrenally insufficient and may lead to inappropriate prescriptions of steroids to patients who do not need them.

THE ROLE OF TUMOR-SEEKING RADIOPHARMACEUTICALS IN THE DIAGNOSIS AND MANAGEMENT OF ADRENAL TUMORS

Context

The variety of tumor-seeking radiopharmaceuticals, which are currently in clinical use, may have a potential role as imaging agents for adrenal gland tumors, due to physiological characteristics of this organ.

Objective

The purpose of this study was to evaluate the diagnostic potential of ^99mTc-HYNIC-TOC, ^99mTc(V)-DMSA, and ^99mTc-MIBI in the assessment of adrenal tumors, by correlating with imaging findings and histopathologic results.

Design

The research is designed as a cross-sectional prospective study.

Patients and method

The study included 50 patients with adrenal tumors (19 hormone-secreting and 31 nonfunctioning) and 23 controls without adrenal involvement. In all patients, single-photon emission computed tomography (SPECT) was performed, using qualitative and semiquantitative analysis. The tumor to non-tumor tracer uptake was conducted by using a region-of-interest technique. Adrenal to background (A/B) ratio was calculated in all cases.

Results

^99mTc-HYNIC-TOC scintigraphy showed a high statistical significance between A/B ratios, while other two tracers resulted in a lower sensitivity, specificity and accuracy. Futhermore, ^99mTc-HYNIC-TOC could have a high diagnostic yield to detect adrenal tumors (the receiver-operating-characteristic curve analysis, A/B ratio cut-off value of 8.40).

Conclusion

A semiquantitative SPECT analysis showed that ^99mTc-HYNIC-TOC is a highly sensitive tumor-seeking agent for the accurate localization of adrenal tumors.

Is Follow-up of Adrenal Incidentalomas Always Mandatory?

Adrenal masses are mainly detected unexpectedly by an imaging study performed for reasons unrelated to any suspect of adrenal diseases. Such masses are commonly defined as "adrenal incidentalomas" and represent a public health challenge because they are increasingly recognized in current medical practice. Management of adrenal incidentalomas is currently matter of debate. Although there is consensus on the need of a multidisciplinary expert team evaluation and surgical approach in patients with significant hormonal excess and/or radiological findings suspicious of malignancy demonstrated at the diagnosis or during follow-up, the inconsistency between official guidelines and the consequent diffuse uncertainty on management of small adrenal incidentalomas still represents a considerable problem in terms of clinical choices in real practice. The aim of the present work is to review the proposed strategies on how to manage patients with adrenal incidentalomas that are not candidates to immediate surgery. The recent European Society of Endocrinology/European Network for the Study of Adrenal Tumors guidelines have supported the view to avoid surveillance in patients with clear benign adrenal lesions <4 cm and/or without any hormonal secretion; however, newer prospective studies are needed to confirm safety of this strategy, in particular in younger patients.

Mitochondrial Dysfunction Pathway Networks and Mitochondrial Dynamics in the Pathogenesis of Pituitary Adenomas

Mitochondrion is a multi-functional organelle, which is associated with various signaling pathway networks, including energy metabolism, oxidative stress, cell apoptosis, cell cycles, autophagy, and immunity process. Mitochondrial proteins have been discovered to modulate these signaling pathway networks, and multiple biological behaviors to adapt to various internal environments or signaling events of human pathogenesis. Accordingly, mitochondrial dysfunction that alters the bioenergetic and biosynthetic state might contribute to multiple diseases, including cell transformation and tumor. Multiomics studies have revealed that mitochondrial dysfunction, oxidative stress, and cell cycle dysregulation signaling pathways operate in human pituitary adenomas, which suggest mitochondria play critical roles in pituitary adenomas. Some drugs targeting mitochondria are found as a therapeutic strategy for pituitary adenomas, including melatonin, melatonin inhibitors, temozolomide, pyrimethamine, 18 beta-glycyrrhetinic acid, gossypol acetate, Yougui pill, T-2 toxin, grifolic acid, cyclosporine A, dopamine agonists, and paeoniflorin. This article reviews the latest experimental evidence and potential biological roles of mitochondrial dysfunction and mitochondrial dynamics in pituitary adenoma progression, potential molecular mechanisms between mitochondria and pituitary adenoma progression, and current status and perspectives of mitochondria-based biomarkers and targeted drugs for effective management of pituitary adenomas.

THE MULTIFARIOUS CUSHING'S - LESSONS FROM A CASE SERIES

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

Overweight Patients Less Improved Kidney Function After Laparoscopic Surgery for Adrenocortical Adenoma With Excess Cortisol Secretion

Purpose: Glucocorticoid (GC) is known to be involved in the deterioration of kidney function both directly by affecting the glomeruli and renal tubules and indirectly by affecting cardiovascular function. Autonomous GC secretion is the main feature of primary adrenal hypercortisolism (PAHC). However, the ideal treatment option (operation vs. medical treatment and observation) for patients with PAHC has not been established yet. In this study, we assessed a time series of kidney function in patients with PAHC treated via laparoscopic adrenalectomy and investigated the predictive factors for kidney function 1 year after surgery. Methods: From September 1997 to July 2017, 175 laparoscopic adrenalectomies were performed for adrenal tumors at Akita University. Thirty patients, who were diagnosed as having PAHC via preoperative endocrinological evaluations and followed up for at least 1 year after surgery, were included in this study. Patients with severe complications or simultaneous aldosteronism were excluded. The mean age of the 30 patients was 57.5 years (range, 33-79 years; males, 4; females, 26), and the right and left sides were affected in 9 and 21 patients, respectively. Results: In all, 18 patients were diagnosed as having Cushing's syndrome and 12 as having subclinical Cushing's syndrome. The steroid cover was required in all cases after surgery. The estimated glomerular filtration rate significantly improved (78.4 mL/min [64.8-95.8] vs. 84.1 mL/min [66.8-104.0], p = 0.012) 1 year after surgery. Patients showing 5% or more improvement in kidney function and those showing less than 5% improvement were compared. On performing univariate analyses, factors such as a longer operative time, heavy body mass index (BMI), and preoperative unsuppressed ACTH were associated with worse improvement in kidney function. No significant associations were observed regarding metabolic disorders, clinical symptoms, and gross proteinuria. On multivariate analysis, patients with a higher BMI (≥ 24 kg/m²) showed worse improvement in kidney function at 1 year after surgery (odds ratio 14.0, 95% confidence interval 1.3-142.9, p = 0.012). Conclusions: In PAHC patients, after 1 year of follow-up, kidney function improved in terms of estimated glomerular filtration rate. Therefore, this improvement seems to be delayed in overweight patients, suggesting its direct role in renal function.