Glucose Metabolism Abnormalities in Cushing Syndrome: From Molecular Basis to Clinical Management

Predictive factors and the management of hyperglycemia in patients with acromegaly and Cushing's disease receiving pasireotide treatment: post hoc analyses from the SOM230B2219 study

Introduction

Pasireotide, a somatostatin receptor ligand, is approved for treating acromegaly and Cushing's disease (CD). Hyperglycemia during treatment can occur because of the drug's mechanism of action, although treatment discontinuation is rarely required. The prospective, randomized, Phase IV SOM230B2219 (NCT02060383) trial was designed to assess optimal management of pasireotide-associated hyperglycemia. Here, we investigated predictive factors for requiring antihyperglycemic medication during pasireotide treatment.

Methods

Participants with acromegaly or CD initiated long-acting pasireotide 40 mg/28 days intramuscularly (acromegaly) or pasireotide 600 μg subcutaneously twice daily during pre-randomization (≤16 weeks). Those who did not need antihyperglycemic medication, were managed with metformin, or received insulin from baseline entered an observational arm ending at 16 weeks. Those who required additional/alternative antihyperglycemic medication to metformin were randomized to incretin-based therapy or insulin for an additional 16 weeks. Logistic-regression analyses evaluated quantitative and qualitative factors for requiring antihyperglycemic medication during pre-randomization.

Results

Of 190 participants with acromegaly and 59 with CD, 88 and 15, respectively, did not need antihyperglycemic medication; most were aged <40 years (acromegaly 62.5%, CD 86.7%), with baseline glycated hemoglobin (HbA1c) <6.5% (<48 mmol/mol; acromegaly 98.9%, CD 100%) and fasting plasma glucose (FPG) <100 mg/dL (<5.6 mmol/L; acromegaly 76.1%, CD 100%). By logistic regression, increasing baseline HbA1c (odds ratio [OR] 3.6; P=0.0162) and FPG (OR 1.0; P=0.0472) and history of diabetes/pre-diabetes (OR 3.0; P=0.0221) predicted receipt of antihyperglycemic medication in acromegaly participants; increasing baseline HbA1c (OR 12.6; P=0.0276) was also predictive in CD participants. Investigator-reported hyperglycemia-related adverse events were recorded in 47.9% and 54.2% of acromegaly and CD participants, respectively, mainly those with diabetes/pre-diabetes.

Conclusion

Increasing age, HbA1c, and FPG and pre-diabetes/diabetes were associated with increased likelihood of requiring antihyperglycemic medication during pasireotide treatment. These risk factors may be used to identify those who need more vigilant monitoring to optimize outcomes during pasireotide treatment.

Cardiac disease in Cushing's syndrome. Emphasis on the role of cardiovascular magnetic resonance imaging

BACKGROUND

Cushing's Syndrome (CS) is associated with increased cardiovascular morbidity and mortality. In endogenous CS, cardiovascular mortality remains increased for up to 15 years post remission of hypercortisolism. Similarly, patients with exogenous CS have 4-fold increased incidence of cardiovascular events, regardless of pre-existing cardiovascular disease (CVD).

OBJECTIVE

To present the pathophysiology, prognosis, clinical and imaging phenotype of cardiac disease in CS.

METHODS

A Pubmed search for cardiac disease in CS over the last 20 years was conducted using combinations of relevant terms. Preclinical and clinical studies, as well as review papers reporting on subclinical heart failure (HF), cardiomyopathy, coronary heart disease (CHD), and cardiovascular imaging were selected.

RESULTS

Cardiac disease in CS is associated with direct mineralocorticoid and glucocorticoid receptor activation, increased responsiveness to angiotensin II, ectopic epicardial adiposity, arterial stiffness and endothelial dysfunction, as well as with diabetes mellitus, hypertension, hyperlipidemia, obesity and prothrombotic diathesis. Subclinical HF and cardiomyopathy are principally related to direct glucocorticoid (GC) effects and markedly improve or regress post hypercortisolism remission. In contrast, CHD is related to both direct GC effects and CS comorbidities and persists post cure. In patients without clinical evidence of CVD, echocardiography and cardiac magnetic resonance (CMR) imaging reveal left ventricular hypertrophy, fibrosis, diastolic and systolic dysfunction, with the latter being underestimated by echocardiography. Finally, coronary microvascular disease is encountered in one third of cases.

CONCLUSION

Cardiovascular imaging is crucial in evaluation of cardiac involvement in CS. CMR superiority in terms of reproducibility, operator independency, unrestricted field of view and capability of tissue characterisation makes this modality ideal for future studies.

Metabolic Syndrome Components in Patients with Pituitary Adenoma

Pituitary adenomas are benign tumors of the anterior portion of the pituitary gland (adenohypophysis), representing the 25% of all the tumor alterations. Pituitary adenomas are classified by the type of hormone secreted, cellularity, size, and structural alterations by the hormonal segregation. The diagnosis consists on the histopathological identification of cell types and the image-guided by magnetic resonance or tomography; the treatment can be both pharmacological and surgical. Metabolic Syndrome is the set of clinical conditions that increase the risk of cardiovascular diseases with an estimated prevalence of 25% worldwide. The alterations of metabolic syndrome are obesity, hypertension, dyslipidemia, insulin resistance, and diabetes mellitus type II. Pituitary adenomas and metabolic syndrome have an important relationship, hormone-secreting by pituitary adenomas affects a myriad of signaling pathways, which allows a favorable environment for the appearance of the metabolic syndrome. Moreover, patients with pituitary adenomas are shown to have an improvement in metabolic parameters after the medical/surgical treatment. The objective of this review is to explore the possible mechanisms through which PAs contributes to MetSx.

Maternal Vitamin C Intake during Pregnancy Influences Long-Term Offspring Growth with Timing- and Sex-Specific Effects in Guinea Pigs

Our previous work in guinea pigs revealed that low vitamin C intake during preconception and pregnancy adversely affects fertility, pregnancy outcomes, and foetal and neonatal growth in a sex-dependent manner. To investigate the long-term impact on offspring, we monitored their growth from birth to adolescence (four months), recorded organ weights at childhood equivalence (28 days) and adolescence, and assessed physiological parameters like oral glucose tolerance and basal cortisol concentrations. We also investigated the effects of the timing of maternal vitamin C restriction (early vs. late gestation) on pregnancy outcomes and the health consequences for offspring. Dunkin Hartley guinea pigs were fed an optimal (900 mg/kg feed) or low (100 mg/kg feed) vitamin C diet ad libitum during preconception. Pregnant dams were then randomised into four feeding regimens: consistently optimal, consistently low, low during early pregnancy, or low during late pregnancy. We found that low maternal vitamin C intake during early pregnancy accelerated foetal and neonatal growth in female offspring and altered glucose homeostasis in the offspring of both sexes at an age equivalent to early childhood. Conversely, low maternal vitamin C intake during late pregnancy resulted in foetal growth restriction and reduced weight gain in male offspring throughout their lifespan. We conclude that altered vitamin C during development has long-lasting, sex-specific consequences for offspring and that the timing of vitamin C depletion is also critical, with low levels during early development being associated with the development of a metabolic syndrome-related phenotype, while later deprivation appears to be linked to a growth-faltering phenotype.

Epidemiology and Management of Hypertension and Diabetes Mellitus in Patients with Mild Autonomous Cortisol Secretion: A Review

Mild autonomous cortisol secretion (MACS) is associated with a higher cardiometabolic risk than that observed in patients with nonfunctioning adrenal adenomas and in the general population. In patients with MACS, the excess of glucocorticoids affects various metabolic pathways, leading to different manifestations of metabolic syndrome and other comorbidities. Hypertension and diabetes mellitus are two of the most common cardiometabolic comorbidities associated with MACS, reaching a prevalence of up to 80% and up to 40%, respectively. In addition, they are the comorbidities that experienced a greater improvement after adrenalectomy in patients with MACS. Hypertension pathogenesis is multifactorial, including the coexistence of comorbidities such as obesity or diabetes and the role of the different polymorphisms of the glucocorticoid receptor gene, among others. Glucocorticoid-induced diabetes mellitus is mainly related to the detrimental effects of glucocorticoids on insulin-dependent glucose uptake in peripheral tissues, gluconeogenesis and insulin secretion. There are no specific recommendations for hypertension and diabetes treatment in patients with MACS. Thus, considering the similar underlying pathogenesis of hypertension and diabetes mellitus in overt and mild hypercortisolism, our recommendation is to follow this general stepwise approach: surgically remove the adrenal culprit lesion to induce remission from hypercortisolism; control hypercortisolism with steroidogenesis inhibitors; and treat elevated blood pressure or high glucose levels using carefully selected anti-hypertensives and glucose-lowering medications if blood pressure and glucose levels remain uncontrolled, respectively. In this review, we summarize the epidemiology, physiopathology and management of diabetes mellitus and hypertension in patients with MACS.

Treating the Side Effects of Exogenous Glucocorticoids; Can We Separate the Good From the Bad?

It is estimated that 2% to 3% of the population are currently prescribed systemic or topical glucocorticoid treatment. The potent anti-inflammatory action of glucocorticoids to deliver therapeutic benefit is not in doubt. However, the side effects associated with their use, including central weight gain, hypertension, insulin resistance, type 2 diabetes (T2D), and osteoporosis, often collectively termed iatrogenic Cushing's syndrome, are associated with a significant health and economic burden. The precise cellular mechanisms underpinning the differential action of glucocorticoids to drive the desirable and undesirable effects are still not completely understood. Faced with the unmet clinical need to limit glucocorticoid-induced adverse effects alongside ensuring the preservation of anti-inflammatory actions, several strategies have been pursued. The coprescription of existing licensed drugs to treat incident adverse effects can be effective, but data examining the prevention of adverse effects are limited. Novel selective glucocorticoid receptor agonists and selective glucocorticoid receptor modulators have been designed that aim to specifically and selectively activate anti-inflammatory responses based upon their interaction with the glucocorticoid receptor. Several of these compounds are currently in clinical trials to evaluate their efficacy. More recently, strategies exploiting tissue-specific glucocorticoid metabolism through the isoforms of 11β-hydroxysteroid dehydrogenase has shown early potential, although data from clinical trials are limited. The aim of any treatment is to maximize benefit while minimizing risk, and within this review we define the adverse effect profile associated with glucocorticoid use and evaluate current and developing strategies that aim to limit side effects but preserve desirable therapeutic efficacy.

Practical therapeutic approach in the management of diabetes mellitus secondary to Cushing's syndrome, acromegaly and neuroendocrine tumours

Cushing's syndrome, acromegaly and neuroendocrine disorders are characterized by an excess of counterregulatory hormones, able to induce insulin resistance and glucose metabolism disorders at variable degrees and requiring immediate treatment, until patients are ready to undergo surgery. This review focuses on the management of diabetes mellitus in endocrine disorders related to an excess of counterregulatory hormones. Currently, the landscape of approved agents for treatment of diabetes is dynamic and is mainly patient-centred and not glycaemia-centred. In addition, personalized medicine is more and more required to provide a precise approach to the patient's disease. For this reason, we aimed to define a practical therapeutic algorithm for management of diabetes mellitus in patients with glucagonoma, pheochromocytoma, Cushing's syndrome and acromegaly, based on our practical experience and on the physiopathology of the specific endocrine disease taken into account. This document is addressed to all specialists who approach patients with diabetes mellitus secondary to endocrine disorders characterized by an excess of counterregulatory hormones, in order to take better care of these patients. Care and control of diabetes mellitus should be one of the primary goals in patients with an excess of counterregulatory hormones requiring immediate and aggressive treatment.

Diabetes Mellitus Secondary to Endocrine Diseases: An Update of Diagnostic and Treatment Particularities

Secondary diabetes mellitus is frequently ignored in specialized literature. In this narrative review, the main endocrinopathies accompanied by increased glycemic values are identified, as well as the mechanisms by which the excess or deficiency of certain hormones impact beta cell function or insulin resistance. The main endocrinopathies (acromegaly, Cushing's syndrome, Basedow-Graves' disease, pheochromocytoma, somatostatinoma and glucagonoma) and their characteristics are described along with the impact of hormone changes on blood sugar, body mass index and other parameters associated with diabetes. The overall information regarding the complex molecular mechanisms that cause the risk of secondary diabetes and metabolic syndrome is of crucial importance in order to prevent the development of the disease and its complications and particularly to reduce the cardiovascular risk of these patients. The purpose of this study is to highlight the particular features of endocrine pathologies accompanied by an increased risk of developing diabetes, in the context of personalized therapeutic decision making. The epidemiological, physiopathological, clinical and therapeutic approaches are presented along with the importance of screening for diabetes in endocrine diseases.

Type 1 and other types of diabetes mellitus in the perioperative period. What the anaesthetist should know

Diabetes mellitus is often treated as a uniform disease in the perioperative period. Type 2 diabetes is most commonly encountered, and only a minority of surgical patients have been diagnosed with another type of diabetes. Patients with a specific type of diabetes can be particularly prone to perioperative glycaemic dysregulation. In addition, certain type-related features and pitfalls should be taken into account in the operating theatre. In this narrative review, we discuss characteristics of types of diabetes other than type 2 diabetes relevant to the anaesthetist, based on available literature and data from our clinic.

Pathophysiology of type 2 diabetes and the impact of altered metabolic interorgan crosstalk

Diabetes is a complex and multifactorial disease that affects millions of people worldwide, reducing the quality of life significantly, and results in grave consequences for our health care system. In type 2 diabetes (T2D), the lack of β-cell compensatory mechanisms overcoming peripherally developed insulin resistance is a paramount factor leading to disturbed blood glucose levels and lipid metabolism. Impaired β-cell functions and insulin resistance have been studied extensively resulting in a good understanding of these pathways but much less is known about interorgan crosstalk, which we define as signaling between tissues by secreted factors. Besides hormones and organokines, dysregulated blood glucose and long-lasting hyperglycemia in T2D is associated with changes in metabolism with metabolites from different tissues contributing to the development of this disease. Recent data suggest that metabolites, such as lipids including free fatty acids and amino acids, play important roles in the interorgan crosstalk during the development of T2D. In general, metabolic remodeling affects physiological homeostasis and impacts the development of T2D. Hence, we highlight the importance of metabolic interorgan crosstalk in this review to gain enhanced knowledge of the pathophysiology of T2D, which may lead to new therapeutic approaches to treat this disease.

Possible, probable, and certain hypercortisolism: A continuum in the risk of comorbidity

Hypercortisolism may be considered as a continuum in terms of both hormonal and cardiometabolic abnormalities. It ranges from cases with "normal" hormonal profile and low to intermediate risk of comorbidity to florid cases with clear clinical and hormonal evidence of glucocorticoid excess and clearly increased cardiometabolic risk. Even in patients with nonfunctioning adrenal incidentaloma (NFAI), defined as adrenal incidentaloma with normal results on the currently available hormonal test for evaluation of hypercortisolism, cardiometabolic and mortality risk is higher than in the general population without adrenal lesions. Mild hypercortisolism or autonomous cortisol secretion (ACS) is a term used for patients with adrenal incidentaloma and pathological dexamethasone suppression test (DST) results, but without specific clinical signs of hypercortisolism. It is widely known that this condition is linked to higher prevalence of several cardiometabolic comorbidities, including diabetes, hypertension, osteoporosis and metabolic syndrome, than in patients with NFAI or without adrenal tumor. In case of overt Cushing's syndrome, cardiovascular risk is extremely high, and standard mortality ratio is high, cardiovascular disease being the leading cause of death. The present review summarizes the current evidence for a detrimental cardiometabolic profile in patients with possible (NFAI), probable (ACS) and certain hypercortisolism (overt Cushing's syndrome).

Medical treatment of Cushing's disease with concurrent diabetes mellitus

Cushing's disease (CD) is a severe endocrine disorder characterized by chronic hypercortisolaemia secondary to an overproduction of adrenocorticotropic hormone (ACTH) by a pituitary adenoma. Cortisol excess impairs normal glucose homeostasis through many pathophysiological mechanisms. The varying degrees of glucose intolerance, including impaired fasting glucose, impaired glucose tolerance, and Diabetes Mellitus (DM) are commonly observed in patients with CD and contribute to significant morbidity and mortality. Although definitive surgical treatment of ACTH-secreting tumors remains the most effective therapy to control both cortisol levels and glucose metabolism, nearly one-third of patients present with persistent or recurrent disease and require additional treatments. In recent years, several medical therapies demonstrated prominent clinical efficacy in the management of patients with CD for whom surgery was non-curative or for those who are ineligible to undergo surgical treatment. Cortisol-lowering medications may have different effects on glucose metabolism, partially independent of their role in normalizing hypercortisolaemia. The expanding therapeutic landscape offers new opportunities for the tailored therapy of patients with CD who present with glucose intolerance or DM, however, additional clinical studies are needed to determine the optimal management strategies. In this article, we discuss the pathophysiology of impaired glucose metabolism caused by cortisol excess and review the clinical efficacy of medical therapies of CD, with particular emphasis on their effects on glucose homeostasis.

Effects of Anterior Pituitary Adenomas' Hormones on Glucose Metabolism and Its Clinical Implications

Pituitary adenomas have recently become more common and their incidence is increasing yearly. Functional pituitary tumors commonly secrete prolactin, growth hormones, and adrenocorticotropic hormones, which cause diseases such as prolactinoma, acromegaly, and Cushing's disease, but rarely secrete luteinizing, follicle-stimulating, thyroid-stimulating, and melanocyte-stimulating hormones. In addition to the typical clinical manifestations of functional pituitary tumors caused by excessive hormone levels, some pituitary tumors are also accompanied by abnormal glucose metabolism. The effects of these seven hormones on glucose metabolism are important for the treatment of diabetes secondary to pituitary tumors. This review focuses on the effects of hormones on glucose metabolism, providing important clues for the diagnosis and treatment of related diseases.

Clinical, pathophysiologic, genetic and therapeutic progress in Primary Bilateral Macronodular Adrenal Hyperplasia

Patients with primary bilateral macronodular adrenal hyperplasia (PBMAH) usually present bilateral benign adrenocortical macronodules at imaging and variable levels of cortisol excess. PBMAH is a rare cause of primary overt Cushing's syndrome, but may represent up to one third of bilateral adrenal incidentalomas with evidence of cortisol excess. The increased steroidogenesis in PBMAH is often regulated by various G-protein coupled receptors aberrantly expressed in PBMAH tissues; some receptor ligands are ectopically produced in PBMAH tissues creating aberrant autocrine/paracrine regulation of steroidogenesis. The bilateral nature of PBMAH and familial aggregation, led to the identification of germline heterozygous inactivating mutations of the ARMC5 gene, in 20-25% of the apparent sporadic cases and more frequently in familial cases; ARMC5 mutations/pathogenic variants can be associated with meningiomas. More recently, combined germline mutations/pathogenic variants and somatic events inactivating the KDM1A gene were specifically identified in patients affected by GIP-dependent PBMAH. Functional studies demonstrated that inactivation of KDM1A leads to GIP-receptor (GIPR) overexpression and over or down-regulation of other GPCRs. Genetic analysis is now available for early detection of family members of index cases with PBMAH carrying identified germline pathogenic variants. Detailed biochemical, imaging, and co-morbidities assessment of the nature and severity of PBMAH is essential for its management. Treatment is reserved for patients with overt or mild cortisol/aldosterone or other steroid excesses taking in account co-morbidities. It previously relied on bilateral adrenalectomy; however recent studies tend to favor unilateral adrenalectomy, or less frequently, medical treatment with cortisol synthesis inhibitors or specific blockers of aberrant GPCR.

Animal Models of Cushing's Syndrome

Endogenous Cushing's syndrome is characterized by unique clinical features and comorbidities, and progress in the analysis of its genetic pathogenesis has been achieved. Moreover, prescribed glucocorticoids are also associated with exogenous Cushing's syndrome. Several animal models have been established to explore the pathophysiology and develop treatments for Cushing's syndrome. Here, we review recent studies reporting animal models of Cushing's syndrome with different features and complications induced by glucocorticoid excess. Exogenous corticosterone (CORT) administration in drinking water is widely utilized, and we found that CORT pellet implantation in mice successfully leads to a Cushing's phenotype. Corticotropin-releasing hormone overexpression mice and adrenal-specific Prkar1a-deficient mice have been developed, and AtT20 transplantation methods have been designed to examine the medical treatments for adrenocorticotropic hormone-producing pituitary neuroendocrine tumors. We also review recent advances in the molecular pathogenesis of glucocorticoid-induced complications using animal models.

Diethyl phosphate disrupts hypothalamus-pituitary-adrenal axis endocrine hormones via nuclear receptors GR and Nur77: Integration of evidences from in vivo, in vitro and in silico approaches

Plenty of population epidemiology and cohort studies have found dialkyl phosphates (DAPs) in the urine were related to endocrine hormone disorders. However, we did not know whether these effects were caused by parent organophosphorus pesticides (OPs) or metabolite DAPs, especially the non-specific metabolite diethyl phosphate (DEP), which was the metabolic end product of most widely used diethyl OPs. In this study, animal experiments (in vivo), cell experiments (in vitro), small molecule-protein binding interaction experiments and computer molecular simulations (in silico) were used to explore the disturbing effects and molecular mechanisms of DEP on the hypothalamic-pituitary-adrenal (HPA) axis endocrine hormones. The animal experiments showed that chronic DEP exposure significantly disturbed the serum contents of HPA axis hormones in adult male rats. The target genes of glucocorticoid receptor (GR) in rat liver, including 11β-hsd1 and Pepck1 and PEPCK protein expressions, were down-regulated. Moreover, the gluconeogenic abilities of rats were impaired. However, it did not affect the expression of GR in the rat hypothalamus. These results indicated that the physiological functions of glucocorticoids and GR were damaged. Furthermore, spectroscopy experiments, cell experiments, molecular docking and molecular dynamics simulations also suggested that DEP can bind to nuclear receptors GR and Nur77, affecting their transcription factor functions, and the transcriptional expression levels of their downstream target genes were reduced. The biosynthesis and secretion of adrenocorticotropic hormone and glucocorticoids were blocked. Therefore, DEP can inhibit the production and physiological functions of HPA axis endocrine hormones by disrupting these related proteins and antagonizing nuclear receptors. These results were considered to provide a theoretical basis for strictly controlling the residue limits of OPs and their metabolites in foods, agricultural products and the environment. They also revealed new targets for evaluating the toxicities and risks of pesticide metabolites.

Dexamethasone-Induced Adipose Tissue Redistribution and Metabolic Changes: Is Gene Expression the Main Factor? An Animal Model of Chronic Hypercortisolism

Chronic hypercortisolism has been associated with the development of several metabolic alterations, mostly caused by the effects of chronic glucocorticoid (GC) exposure over gene expression. The metabolic changes can be partially explained by the GC actions on different adipose tissues (ATs), leading to central obesity. In this regard, we aimed to characterize an experimental model of iatrogenic hypercortisolism in rats with significant AT redistribution. Male Wistar rats were distributed into control (CT) and GC-treated, which received dexamethasone sodium phosphate (0.5 mg/kg/day) by an osmotic minipump, for 4 weeks. GC-treated rats reproduced several characteristics observed in human hypercortisolism/Cushing’s syndrome, such as HPA axis inhibition, glucose intolerance, insulin resistance, dyslipidemia, hepatic lipid accumulation, and AT redistribution. There was an increase in the mesenteric (meWAT), perirenal (prWAT), and interscapular brown (BAT) ATs mass, but a reduction of the retroperitoneal (rpWAT) mass compared to CT rats. Overexpressed lipolytic and lipogenic gene profiles were observed in white adipose tissue (WAT) of GC rats as BAT dysfunction and whitening. The AT remodeling in response to GC excess showed more importance than the increase of AT mass per se, and it cannot be explained just by GC regulation of gene transcription.

Fresh insights into glucocorticoid-induced diabetes mellitus and new therapeutic directions

Glucocorticoid hormones were discovered to have use as potent anti-inflammatory and immunosuppressive therapeutics in the 1940s and their continued use and development have successfully revolutionized the management of acute and chronic inflammatory diseases. However, long-term use of glucocorticoids is severely hampered by undesirable metabolic complications, including the development of type 2 diabetes mellitus. These effects occur due to glucocorticoid receptor activation within multiple tissues, which results in inter-organ crosstalk that increases hepatic glucose production and inhibits peripheral glucose uptake. Despite the high prevalence of glucocorticoid-induced hyperglycaemia associated with their routine clinical use, treatment protocols for optimal management of the metabolic adverse effects are lacking or underutilized. The type, dose and potency of the glucocorticoid administered dictates the choice of hypoglycaemic intervention (non-insulin or insulin therapy) that should be provided to patients. The longstanding quest to identify dissociated glucocorticoid receptor agonists to separate the hyperglycaemic complications of glucocorticoids from their therapeutically beneficial anti-inflammatory effects is ongoing, with selective glucocorticoid receptor modulators in clinical testing. Promising areas of preclinical research include new mechanisms to disrupt glucocorticoid signalling in a tissue-selective manner and the identification of novel targets that can selectively dissociate the effects of glucocorticoids. These research arms share the ultimate goal of achieving the anti-inflammatory actions of glucocorticoids without the metabolic consequences.

Metabolomics Profiling of Pituitary Adenomas by Raman Spectroscopy, Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy, and Mass Spectrometry of Serum Samples

To date, no studies are available in which pituitary adenomas (PAs) have been studied using techniques like confocal Raman spectroscopy, attenuated total reflection-Fourier transform infrared (FT-IR), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the same serum samples. To understand the metabolomics fingerprint, Raman spectra of 16 acromegaly, 19 Cushing's, and 33 nonfunctional PA (NFPA) and ATR-FTIR spectral acquisition of 16 acromegaly, 18 Cushing's, and 22 NFPA patient's serum samples were acquired. Next, Principal component-based linear discriminant analysis (PC-LDA) models were developed, Raman spectral analysis classified acromegaly with an accuracy of 79.17%, sensitivity of 75%, and specificity of 81.25%, Cushing's with an accuracy of 66.67%, sensitivity of 100%, and specificity of 52.63%, and NFPA with an accuracy of 73.17%, sensitivity of 75%, and specificity of 72.73%. ATR-FTIR spectral analysis classified acromegaly with an accuracy of 95.83%, sensitivity of 100%, and specificity of 93.75%, Cushing's with an accuracy of 65.38%, sensitivity of 87.5%, and specificity of 55.56%, and NFPA with an accuracy of 70%, sensitivity of 87.5%, and specificity of 43.75%. In either of the cases, healthy individual cohorts were clearly segregated from the disease cohort, which identified differential regulated regions of nucleic acids, lipids, amides, phosphates, and polysaccharide/C-C residue α helix regions. Furthermore, LC-MS/MS-based analysis of sera samples resulted in the identification of various sphingosine, lipids, acylcarnitines, amino acids, ethanolamine, choline, and their derivatives that differentially regulated in each tumor cohort. We believe cues obtained from the study may be used to generate the metabolite-based test to diagnose PAs from serum in addition to conventional techniques and also to understand disease biology for better disease management, point of care, and improving quality of life in PA patients.

Glucose and lipid metabolism abnormalities in Cushing's syndrome

Prolonged excess of glucocorticoids (GCs) has adverse systemic effects leading to significant morbidities and an increase in mortality. Metabolic alterations associated with the high level of the GCs are key risk factors for the poor outcome. These include GCs causing excess gluconeogenesis via upregulation of key enzymes in the liver, a reduction of insulin sensitivity in skeletal muscle, liver and adipose tissue by inhibiting the insulin receptor signalling pathway, and inhibition of insulin secretion in beta cells leading to dysregulated glucose metabolism. In addition, chronic GC exposure leads to an increase in visceral adipose tissue, as well as an increase in lipolysis resulting in higher circulating free fatty acid levels and in ectopic fat deposition. Remission of hypercortisolism improves these metabolic changes, but very often does not result in full resolution of the abnormalities. Therefore, long-term monitoring of metabolic variables is needed even after the resolution of the excess GC levels.

β-cell function and insulin sensitivity contributions on incident diabetes in patients with endogenous Cushing's syndrome

OBJECTIVE

To evaluate the relative contributions of β-cell function and insulin sensitivity on the deterioration of glucose tolerance from OGTT in patients with endogenous CS.

METHODS

We retrospectively analyzed the data of 60 patients with CS and determined the glucose metabolism and β-cell function through OGTT. Their general characteristics were retrieved. A series of parameters for assessing insulin sensitivity and β-cell function was calculated. The logistic regression model was used to investigate insulin sensitivity and β-cell function contributions on incident diabetes.

RESULTS

Of the 60 patients with CS, 10 (16.7%), 21 (35%), and 29 (48.3%) were classified as CS/ normal glucose tolerance (NGT), CS/prediabetes, and CS/diabetes mellitus (DM). Compared with the HCs, the CS/NGT patients had higher HOMA-IR and lower ISI-Matsuda but with a compensatory increase in HOMA-β. Significant decreasing trends were observed in HOMA-β, AUC_I/G and ΔI₃₀/ΔG₃₀ among CS/NGT, CS/prediabetes and CD/DM groups. The OR of incident diabetes compared with the high AUC_I/G/high ISI group was significant in the low AUC_I/G/high ISI group.

CONCLUSION

Impairment of the β-cell function had a more profound effect on incident diabetes than decreased insulin sensitivity. An approach based on an OGTT has utility for diagnosing dysglycaemia and β-cell dysfunction in patients with CS.

New Insights into the Role of Insulin and Hypothalamic-Pituitary-Adrenal (HPA) Axis in the Metabolic Syndrome

Recent data suggests that (pre)diabetes onset is preceded by a period of hyperinsulinemia. Consumption of the "modern" Western diet, over-nutrition, genetic background, decreased hepatic insulin clearance, and fetal/metabolic programming may increase insulin secretion, thereby causing chronic hyperinsulinemia. Hyperinsulinemia is an important etiological factor in the development of metabolic syndrome, type 2 diabetes, cardiovascular disease, polycystic ovarian syndrome, and Alzheimer's disease. Recent data suggests that the onset of prediabetes and diabetes are preceded by a variable period of hyperinsulinemia. Emerging data suggest that chromic hyperinsulinemia is also a driving force for increased activation of the hypothalamic-adrenal-pituitary (HPA) axis in subjects with the metabolic syndrome, leading to a state of "functional hypercortisolism". This "functional hypercortisolism" by antagonizing insulin actions may prevent hypoglycemia. It also disturbs energy balance by shifting energy fluxes away from muscles toward abdominal fat stores. Synergistic effects of hyperinsulinemia and "functional hypercortisolism" promote abdominal visceral obesity and insulin resistance which are core pathophysiological components of the metabolic syndrome. It is hypothesized that hyperinsulinemia-induced increased activation of the HPA axis plays an important etiological role in the development of the metabolic syndrome and its consequences. Numerous studies have demonstrated reversibility of hyperinsulinemia with lifestyle, surgical, and pharmaceutical-based therapies. Longitudinal studies should be performed to investigate whether strategies that reduce hyperinsulinemia at an early stage are successfully in preventing increased activation of the HPA axis and the metabolic syndrome.

Incretin Response to Mixed Meal Challenge in Active Cushing's Disease and after Pasireotide Therapy

Cushing’s disease (CD) causes diabetes mellitus (DM) through different mechanisms in a significant proportion of patients. Glucose metabolism has rarely been assessed with appropriate testing in CD; we aimed to evaluate hormonal response to a mixed meal tolerance test (MMTT) in CD patients and analyzed the effect of pasireotide (PAS) on glucose homeostasis. To assess gastro-entero-pancreatic hormones response in diabetic (DM+) and non-diabetic (DM−) patients, 26 patients with CD underwent an MMTT. Ten patients were submitted to a second MMTT after two months of PAS 600 µg twice daily. The DM+ group had significantly higher BMI, waist circumference, glycemia, HbA1c, ACTH levels and insulin resistance indexes than DM− (p < 0.05). Moreover, DM+ patients exhibited increased C-peptide (p = 0.004) and glucose area under the curve (AUC) (p = 0.021) during MMTT, with a blunted insulinotropic peptide (GIP) response (p = 0.035). Glucagon levels were similar in both groups, showing a quick rise after meals. No difference in estimated insulin secretion and insulin:glucagon ratio was found. After two months, PAS induced an increase in both fasting glycemia and HbA1c compared to baseline (p < 0.05). However, this glucose trend after meal did not worsen despite the blunted insulin and C-peptide response to MMTT. After PAS treatment, patients exhibited reduced insulin secretion (p = 0.005) and resistance (p = 0.007) indexes. Conversely, glucagon did not change with a consequent impairment of insulin:glucagon ratio (p = 0.009). No significant differences were observed in incretins basal and meal-induced levels. Insulin resistance confirmed its pivotal role in glucocorticoid-induced DM. A blunted GIP response to MMTT in the DM+ group might suggest a potential inhibitory role of hypercortisolism on enteropancreatic axis. As expected, PAS reduced insulin secretion but also induced an improvement in insulin sensitivity as a result of cortisol reduction. No differences in incretin response to MMTT were recorded during PAS therapy. The discrepancy between insulin and glucagon trends while on PAS may be an important pathophysiological mechanism in this iatrogenic DM; hence restoring insulin:glucagon ratio by either enhancing insulin secretion or reducing glucagon tone can be a potential therapeutic target.

Cushing Syndrome in a Pediatric Patient with Topical Steroid Overuse

Cushing syndrome is a state of hypercortisolism from exogenous or endogenous exposure to glucocorticoids resulting in various clinical manifestations. In this case report, we present a case of a 15-month-old child who presented with cushingoid facies due to over-the-counter misuse of a very potent topical steroid (clobetasol 0.05%) for suspected scabies. Laboratory measurement of urinary free cortisol level was low, and 8 : 00 am basal cortisol level was measured, which was decreased, which confirmed the diagnosis of Cushing syndrome due to exogenous source. Over-the-counter topical steroids should not be used, and one should always consult a registered medical practitioner before using such products. Physicians when prescribing topical steroids should warn patients about the potential side effects of prolonged use of topical steroids.

Perioperative Management of a Patient with Cushing’s Disease

Patients with Cushing’s disease (CD) may present with both chronic and acute perioperative complications that necessitate multidisciplinary care. This review highlights several objectives for these patients before and after transsphenoidal surgery. Preoperative management includes treatment of electrolyte disturbances, cardiovascular comorbidities, prediabetes/diabetes, as well as prophylactic consideration(s) for thromboembolism and infection(s). Preoperative medical therapy (PMT) could prove beneficial in patients with severe hypercortisolism or in cases of delayed surgery. Some centers use PMT routinely, although the clinical benefit for all patients is controversial. In this setting, steroidogenesis inhibitors are preferred because of rapid and potent inhibition of cortisol secretion. If glucocorticoids are not used perioperatively, an immediate remission assessment postoperatively is possible. However, perioperative glucocorticoid replacement is sometimes necessary for clinically unstable or medically pretreated patients and for those patients with surgical complications. A nadir serum cortisol &lt; 2-5µg/dl during 24-74 hours postoperatively is generally accepted as remission; higher values suggest non-remission, while a few patients may display delayed remission. If remission is not achieved, additional treatments are pursued. The early postoperative period necessitates multidisciplinary awareness for early diagnosis of adrenal insufficiency (AI) to avoid adrenal crisis, which may be also potentiated by acute postoperative complications. Preferred glucocorticoid replacement is hydrocortisone, if available. Assessment of recovery from postoperative AI should be undertaken periodically. Other postoperative targets include decreasing antihypertensive/diabetic therapy if in remission, thromboprophylaxis, infection prevention/treatment, and management of electrolyte disturbances and/or potential pituitary deficiencies. Evaluation of recovery of thyroid, gonadal and growth hormone deficiencies should be also performed in the following months postoperatively.

The Effect of Curative Treatment on Hyperglycemia in Patients With Cushing Syndrome

Context

Hyperglycemia is a common complication of Cushing syndrome (CS).

Objective

We aimed to determine the impact of curative procedure on hyperglycemia and its management in patients with CS.

Methods

This retrospective longitudinal cohort study took place 2000 to 2019 in a referral center among adults with endogenous CS and hyperglycemia. Main outcome measures included glycated hemoglobin A_1c (HbA1c), intensity of hyperglycemia therapy, and improvement of hyperglycemia.

Results

In 174 patients with CS (pituitary in 106, ectopic in 25, adrenal in 43), baseline median HbA_1c was 6.9% (range, 4.9-13.1), with 41 (24%) patients not on any therapy for hyperglycemia, 93 (52%) on oral medications, and 64 (37%) on insulin (median daily units of 58; range, 10-360). Following CS remission, at the end of follow-up (median 10.5 months), 37 (21%) patients demonstrated resolution of hyperglycemia, 82 (47%) demonstrated improvement, and 55 (32%) had no change or worsening in hyperglycemia. At the end of follow-up, HbA_1c decreased by 0.84% (P < .001) and daily insulin dose decreased by a mean of 30 units (P < .001). Biochemical hypercortisolism severity score (severe vs moderate/mild: odds ratio [OR] of 2.4 [95% CI, 1.1-4.9]), and CS subtype (nonadrenal vs adrenal: OR of 2.9 [95% CI, 1.3-6.4]), but not type of hyperglycemia (diabetes vs prediabetes: OR of 2.1 [0.9-4.9]) were associated with hyperglycemia improvement at the end of follow-up.

Conclusion

Two-thirds of patients with CS and hyperglycemia demonstrate resolution or improvement of hyperglycemia after a curative procedure. Close monitoring during CS recovery is needed to ensure appropriate therapy modification.

Managing pasireotide-associated hyperglycemia: a randomized, open-label, Phase IV study

PURPOSE

Pasireotide is an effective treatment for acromegaly and Cushing's disease, although treatment-emergent hyperglycemia can occur. The objective of this study was to assess incretin-based therapy versus insulin for managing pasireotide-associated hyperglycemia uncontrolled by metformin/other permitted oral antidiabetic drugs.

METHODS

Multicenter, randomized, open-label, Phase IV study comprising a core phase (≤ 16-week pre-randomization period followed by 16-week randomized treatment period) and optional extension (ClinicalTrials.gov ID: NCT02060383). Adults with acromegaly (n = 190) or Cushing's disease (n = 59) received long-acting (starting 40 mg IM/28 days) or subcutaneous pasireotide (starting 600 µg bid), respectively. Patients with increased fasting plasma glucose (≥ 126 mg/dL on three consecutive days) during the 16-week pre-randomization period despite metformin/other oral antidiabetic drugs were randomized 1:1 to open-label incretin-based therapy (sitagliptin followed by liraglutide) or insulin for another 16 weeks. The primary objective was to evaluate the difference in mean change in HbA_1c from randomization to end of core phase between incretin-based therapy and insulin treatment arms.

RESULTS

Eighty-one (32.5%) patients were randomized to incretin-based therapy (n = 38 received sitagliptin, n = 28 subsequently switched to liraglutide; n = 12 received insulin as rescue therapy) or insulin (n = 43). Adjusted mean change in HbA_1c between treatment arms was - 0.28% (95% CI - 0.63, 0.08) in favor of incretin-based therapy. The most common AE other than hyperglycemia was diarrhea (incretin-based therapy, 28.9%; insulin, 30.2%). Forty-six (18.5%) patients were managed on metformin (n = 43)/other OAD (n = 3), 103 (41.4%) patients did not require any oral antidiabetic drugs and 19 patients (7.6%) were receiving insulin at baseline and were not randomized.

CONCLUSION

Many patients receiving pasireotide do not develop hyperglycemia requiring oral antidiabetic drugs. Metformin is an effective initial treatment, followed by incretin-based therapy if needed. ClinicalTrials.gov ID: NCT02060383.

Glucocorticoid excess and COVID-19 disease

The pandemic of coronavirus disease (COVID-19), a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is causing high and rapid morbidity and mortality. Immune system response plays a crucial role in controlling and resolving the viral infection. Exogenous or endogenous glucocorticoid excess is characterized by increased susceptibility to infections, due to impairment of the innate and adaptive immune system. In addition, diabetes, hypertension, obesity and thromboembolism are conditions overrepresented in patients with hypercortisolism. Thus patients with chronic glucocorticoid (GC) excess may be at high risk of developing COVID-19 infection with a severe clinical course. Care and control of all comorbidities should be one of the primary goals in patients with hypercortisolism requiring immediate and aggressive treatment. The European Society of Endocrinology (ESE), has recently commissioned an urgent clinical guidance document on management of Cushing's syndrome in a COVID-19 period. In this review, we aim to discuss and expand some clinical points related to GC excess that may have an impact on COVID-19 infection, in terms of both contagion risk and clinical outcome. This document is addressed to all specialists who approach patients with endogenous or exogenous GC excess and COVID-19 infection.

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.

Unilateral adrenalectomy partially improved hyperglycemia in a patient with primary bilateral macronodular adrenal hyperplasia

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is characterized by bilateral multiple adrenal macro-nodules that often cause mild over-secretion of cortisol in the form of subclinical Cushing's syndrome. We herein describe a case, wherein unilateral adrenalectomy partially improved hyperglycemia in a patient with PBMAH and suggest the usefulness and limitations of this surgical strategy. A 64-year-old woman with type 2 diabetes had an incidental diagnosis of bilateral adrenal lesions. She had a family history of type 2 diabetes, and her HbA1c level was 8.9% under insulin therapy. She did not present with any symptoms associated with Cushing's syndrome. The basal cortisol level was in the normal range (12.0 μg/dL); however, the adrenocorticotropic hormone (ACTH) level was suppressed (2.1 pg/mL) and the serum cortisol level was not suppressed in the dexamethasone test. Computed tomography and magnetic resonance imaging showed bilateral adrenal macro-nodules and ¹³¹I-adosterol accumulated in the bilateral adrenal lesions. Collectively, she was diagnosed with subclinical Cushing's syndrome due to PBMAH complicated with diabetes mellitus, hypertension, and dyslipidemia. Laparoscopic left adrenalectomy was performed, and the pathologic findings were consistent with PBMAH. After unilateral adrenalectomy, serum cortisol levels decreased, and hypertension improved. Both HbA1c levels and insulin requirement also decreased, but insulin therapy was continuously needed. It should be noted that hyperglycemia may not be cured after successful surgery in a patient with PBMAH. Additional operation or medical therapy should be considered if unilateral adrenalectomy is unable to correct hypercortisolism in PBMAH patients.

A multidisciplinary approach to the management of adrenal incidentaloma

An adrenal incidentaloma (AI) is an adrenal neoplasm incidentally discovered during an imaging unrelated to suspected adrenal disease. The aim of the present review is to offer practical guidance on the multidisciplinary approach of AIs.Areas covered:The prevalence of AI is high in the aging population (up to 5-8%); however, hormonally active or malignant conditions are rare. After the discovery of an AI, it is suggested to assess in parallel if the mass is potentially malignant and functionally active. The answer to the former question is mainly based on medical history (extra-adrenal malignancies, new-onset of signs or symptoms) and imaging (conventional radiology and/or nuclear medicine). The answer to the latter question is a complete endocrine evaluation of both cortical (glucocorticoids, mineralocorticoids) and medullary (catecholamines) secretion.Expert opinion:A multidisciplinary discussion is suggested for patients with adrenal disease, after the exclusion of nonfunctioning benign cortical adenoma, in order to plan a close and tailored follow-up for the suspected malignant or functioning forms. Surgery is advised for patients with malignant disease (adrenocortical cancer) or with clinically relevant secreting neoplasm (primary aldosteronism, Cushing's syndrome, and pheochromocytoma).

Early post-natal life stress induces permanent adrenocorticotropin-dependent hypercortisolism in male mice

PURPOSE

It has been hypothesized that specific early-life stress (ES) procedures on CD-1 male mice produce diabetes-like alterations due to the failure of negative feedback of glucocorticoid hormone in the pituitary. The aim of this study is to investigate the possible mechanism that leads to this pathological model, framing it in a more specific clinical condition.

METHODS

Metabolic and hypothalamic-pituitary-adrenal-related hormones of stressed mice (SM) have been analyzed immediately after stress procedures (21 postnatal days, PND) and after 70 days of a peaceful (unstressed) period (90 PND). These data have been compared to parameters from age-matched controls (CTR), and mice treated during ES procedures with oligonucleotide antisense for pro-opiomelanocortin (AS-POMC).

RESULTS

At 21 PND, SM presented an increased secretion of hypothalamic CRH and pituitary POMC-derived peptides, as well as higher plasmatic levels of ACTH and corticosterone vs. CTR. At 90 PND, SM showed hyperglycemia, with suppression of hypothalamic CRH, while pituitary and plasmatic ACTH levels, as well as plasma corticosterone, were constantly higher than in CTR. These values are accompanied by a progressive acceleration in gaining total body weight, which became significant vs. CTR at 90 PND together with a higher pituitary weight. Treatment with AS-POMC prevented all hormonal and metabolic alterations observed in SM, both at 21 and 90 PND.

CONCLUSIONS

These findings show that these specific ES procedures affect the negative glucocorticoid feedback in the pituitary, but not in the hypothalamus, suggesting a novel model of ACTH-dependent hypercortisolism that can be prevented by silencing the POMC gene.

COVID-19 and the pituitary

BACKGROUND

Despite COVID-19 being identified as severe respiratory viral infection, progressively many relevant endocrine manifestations have been reported greatly contributing to the severity of the clinical presentation. Systemic involvement in COVID-19 is due to the ubiquitous expression of angiotensin-converting enzyme 2 (ACE2) receptor, responsible for the entry in the cells of SARS-CoV-2, Several reports in humans and animal models showed a significant ACE2 mRNA expression in hypothalamus and pituitary cells. Moreover, higher mortality and poorer outcomes have been widely described in COVID-19 patients with obesity, diabetes and vertebral fractures, which are all highly prevalent in subjects with pituitary dysfunctions.

AIM

To review the main endocrine manifestations of COVID-19 with their possible implications for pituitary diseases, the possible direct and indirect involvement of the pituitary gland in COVID-19, the impact of COVID-19 on the management of established pituitary diseases which can be already at increased risk for worse outcomes and on neurosurgical activities as well as vaccination.

CONCLUSIONS

Our review underlines that there could be a specific involvement of the pituitary gland which fits into a progressively shaping endocrine phenotype of COVID-19. Moreover, the care for pituitary diseases need to continue despite the restrictions due to the emergency. Several pituitary diseases, such as hypopituitarism and Cushing disease, or due to frequent comorbidities such as diabetes may be a risk factor for severe COVID-19 in affected patients. There is the urgent need to collect in international multicentric efforts data on all these aspects of the pituitary involvement in the pandemic in order to issue evidence driven recommendations for the management of pituitary patients in the persistent COVID-19 emergency.

Central nervous system regulation of organismal energy and glucose homeostasis

Growing evidence implicates the brain in the regulation of both immediate fuel availability (for example, circulating glucose) and long-term energy stores (that is, adipose tissue mass). Rather than viewing the adipose tissue and glucose control systems separately, we suggest that the brain systems that control them are components of a larger, highly integrated, 'fuel homeostasis' control system. This conceptual framework, along with new insights into the organization and function of distinct neuronal systems, provides a context within which to understand how metabolic homeostasis is achieved in both basal and postprandial states. We also review evidence that dysfunction of the central fuel homeostasis system contributes to the close association between obesity and type 2 diabetes, with the goal of identifying more effective treatment options for these common metabolic disorders.

Serum- and glucocorticoid-inducible kinase 1 promotes insulin resistance in adipocytes via degradation of insulin receptor substrate 1

AIMS

Accumulating evidence indicates that serum- and glucocorticoid-inducible kinase 1 (SGK1) plays a role in the development of metabolic syndrome via a poorly understood mechanism. This study aimed to investigate the direct effect of SGK1 on insulin sensitivity in adipose tissue.

MATERIALS AND METHODS

We ectopically expressed or silenced SGK1 in adipocytes via lentiviral transfection, measured glucose uptake and evaluated insulin signalling using western blotting. In vivo insulin resistance was measured at the whole-body and adipose tissue levels in db/db mice treated with an inhibitor of SGK1.

RESULTS

After 8 weeks of SGK1 inhibitor treatment, the serum insulin level and homeostasis model assessment of insulin resistance index were significantly decreased, and AKT phosphorylation in adipose tissue was enhanced in db/db mice. Overexpression of constitutively active SGK1 in adipocytes in vitro decreased AKT phosphorylation and insulin-stimulated glucose uptake. Dexamethasone and oleic acid increased SGK1 expression and decreased AKT phosphorylation and insulin receptor substrate expression in adipocytes. Administration of an inhibitor of SGK1 or Lv-shSGK1 reversed the suppression of insulin signalling induced by dexamethasone and oleic acid. SGK1 overexpression increased FoxO1 phosphorylation, and administration of Lv-shSGK1 reversed an increase in FoxO1 phosphorylation induced by dexamethasone and oleic acid.

CONCLUSIONS

Thus, SGK1 mediates the effect of glucocorticoids and high-fat feeding and induces insulin resistance in adipocytes. Our data suggest that SGK1 is a possible therapeutic target for metabolic syndrome and related complications.

Associations of Serum Cortisol with Cardiovascular Risk and Mortality in Patients Referred to Coronary Angiography

CONTEXT

Serum cortisol may be associated with cardiovascular risk factors and mortality in patients undergoing coronary angiography, but previous data on this topic are limited and controversial.

OBJECTIVE

We evaluated whether morning serum cortisol is associated with cardiovascular risk factors, lymphocyte subtypes, and mortality.

METHODS

This is a prospective cohort study performed at a tertiary care centre in south-west Germany between 1997 and 2000. We included 3052 study participants who underwent coronary angiography. The primary outcome measures were cardiovascular risk factors, lymphocyte subtypes, and all-cause and cardiovascular mortality.

RESULTS

Serum cortisol was associated with an adverse cardiovascular risk profile, but there was no significant association with coronary artery disease or acute coronary syndrome. In a subsample of 2107 participants, serum cortisol was positively associated with certain lymphocyte subsets, including CD16+CD56+ (natural killer) cells (P < 0.001). Comparing the fourth versus the first serum cortisol quartile, the crude Cox proportional hazard ratios (with 95% CIs) were 1.22 (1.00-1.47) for all-cause and 1.32 (1.04-1.67) for cardiovascular mortality, respectively. After adjustments for various cardiovascular risk factors, these associations were attenuated to 0.93 (0.76-1.14) for all-cause, and 0.97 (0.76-1.25) for cardiovascular mortality, respectively.

CONCLUSIONS

Despite significant associations with classic cardiovascular risk factors and natural killer cells, serum cortisol was not a significant and independent predictor of mortality in patients referred to coronary angiography. These findings might reflect that adverse cardiovascular effects of cortisol could be counterbalanced by some cardiovascular protective actions.

Mifepristone Improves Adipose Tissue Insulin Sensitivity in Insulin Resistant Individuals

BACKGROUND

Increased tissue cortisol availability has been implicated in abnormal glucose and fat metabolism in patients with obesity, metabolic syndrome, and type 2 diabetes (T2DM). Our objective was to evaluate whether blockade of glucocorticoid receptor (GR) with mifepristone ameliorates insulin resistance (IR) in overweight/obese subjects with glucose intolerance.

METHODS

We conducted a randomized, double-blinded, placebo-controlled, crossover study in overweight/obese individuals (n = 16, 44% female) with prediabetes or mild T2DM but not clinical hypercortisolism. Mifepristone (50 mg every 6 h) or placebo was administered for 9 days, followed by crossover to the other treatment arm after a washout period of 6 to 8weeks. At baseline and following each treatment, oral glucose tolerance test (OGTT) and frequently sampled intravenous glucose tolerance test (FSIVGTT) were performed. Insulin sensitivity was measured using FSIVGTT [primary outcome: insulin sensitivity index (SI)] and OGTT [Matsuda index (MI) and oral glucose insulin sensitivity index (OGIS)]. Hepatic and adipose insulin resistance were assessed using hepatic insulin resistance index (HIRI), and adipose tissue insulin sensitivity index (Adipo-SI) and adipo-IR, derived from the FSIVGTT.

RESULTS

Mifepristone administration did not alter whole-body glucose disposal indices of insulin sensitivity (SI, MI, and OGIS). GR blockade significantly improved Adipo-SI (61.7 ± 32.9 vs 42.8 ± 23.9; P = 0.002) and reduced adipo-IR (49.9 ± 45.9 vs 65.5 ± 43.8; P = 0.004), and HIRI (50.2 ± 38.7 vs 70.0 ± 44.3; P = 0.08). Mifepristone increased insulin clearance but did not affect insulin secretion or β-cell glucose sensitivity.

CONCLUSION

Short-term mifepristone administration improves adipose and hepatic insulin sensitivity among obese individuals with hyperglycemia without hypercortisolism.

Levoketoconazole in the Treatment of Patients With Cushing's Syndrome and Diabetes Mellitus: Results From the SONICS Phase 3 Study

Background

Cushing's syndrome (CS) is associated with numerous comorbidities, including diabetes mellitus (DM). Levoketoconazole, an orally administered ketoconazole stereoisomer, is in clinical trials for the treatment of CS.

Methods

SONICS, a prospective, open-label, phase 3 study in adults with confirmed CS and mean 24-h urinary free cortisol (mUFC) ≥1.5× ULN, included dose-titration, 6-month maintenance, and 6-month extension phases. This subanalysis evaluated the efficacy of levoketoconazole in patients with DM (n = 28) or without DM (n = 49) who entered the maintenance phase. Safety was evaluated in the overall population (N = 94) during the dose-titration and maintenance phases.

Results

Normalization of mUFC at the end of maintenance phase (EoM), without a dose increase during maintenance (SONICS primary endpoint) was observed in 46% of patients with DM (95% CI, 28 to 66%; P = 0.0006 vs null hypothesis of ≤20%) and 33% of patients without DM (95% CI, 20 to 48%; P = 0.0209). At EoM, mean HbA1c decreased from 6.9% at baseline to 6.2% in patients with DM and from 5.5 to 5.3% in patients without DM. Mean fasting blood glucose decreased from 6.85 mmol/L (123.4 mg/dl) to 5.82 mmol/L (104.9 mg/dl) and from 5.11 mmol/L (92.1 mg/dl) to 4.66 mmol/L (84.0 mg/dl) in patients with and without DM, respectively. Adverse events that were more common in patients with DM included nausea (58.3%), vomiting (19.4%), and urinary tract infection (16.7%); none prompted study drug withdrawal.

Conclusions

Treatment with levoketoconazole led to sustained normalization of mUFC and improvement in glycemic control that was more pronounced in patients with DM.

Clinical Trial Registration

(ClinicalTrials.gov), NCT01838551.

Glucocorticoids, metabolism and brain activity

The review integrates different experimental approaches including biochemistry, c-Fos expression, microdialysis (glutamate, GABA, noradrenaline and serotonin), electrophysiology and fMRI to better understand the effect of elevated level of glucocorticoids on the brain activity and metabolism. The available data indicate that glucocorticoids alter the dynamics of neuronal activity leading to context-specific changes including both excitation and inhibition and these effects are expected to support the task-related responses. Glucocorticoids also lead to diversification of available sources of energy due to elevated levels of glucose, lactate, pyruvate, mannose and hydroxybutyrate (ketone bodies), which can be used to fuel brain, and facilitate storage and utilization of brain carbohydrate reserves formed by glycogen. However, the mismatch between carbohydrate supply and utilization that is most likely to occur in situations not requiring energy-consuming activities lead to metabolic stress due to elevated brain levels of glucose. Excessive doses of glucocorticoids also impair the production of energy (ATP) and mitochondrial oxidation. Therefore, glucocorticoids have both adaptive and maladaptive effects consistently with the concept of allostatic load and overload.

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.

The Quantitative Relationship Between Autonomous Cortisol Secretion, Dysglycemia and the Metabolic Syndrome

OBJECTIVE

Autonomous cortisol secretion (ACS) is the most common endocrine abnormality in the evaluation of adrenal incidentalomas. The categorization of ACS is derived from a 1 mg dexamethasone suppression test (DST). Impaired DST is associated with several metabolic derangements. In this study we analyzed the association between post-DST cortisol level, analyzed as a continuous parameter, and indices of glycemic metabolism.

METHODS

We prospectively collected data of 1,976 patients evaluated for adrenal incidentalomas in a large tertiary medical center between December 1, 2017, and August 31, 2019. Seventy-three patients completed the evaluation process. Post-DST cortisol levels were analyzed for correlation with various metabolic parameters, including fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) among the general cohort and for subgroups stratified by the number of metabolic syndrome (MS) criteria.

RESULTS

Post-DST cortisol demonstrated a linear association with FPG and HbA1c across its entire cortisol range (R = 0.51 and 0.41, respectively; P≤.01). The association between post-DST cortisol and FPG was strengthened with an increased number of metabolic syndrome criteria. Patients with 4 MS criteria show a stronger association (R = 0.92) compared to patients with only a single criterion (R = 0.509). Furthermore, mean post-DST cortisol levels increased as the number of MS criteria accumulated.

CONCLUSION

Post-DST cortisol should be viewed as a continuous parameter in risk stratification algorithms for the development of MS and particularly dysglycemia.

Preoperative prognostic nomogram for prophylactic steroid treatment of patients with subclinical Cushing's syndrome

Background

Subclinical Cushing’s syndrome (SCS) is incidentally detected in a growing number of patients by advanced imaging technology. However, there is no consensus on the clinical management of SCS, especially in terms of whether prophylactic steroid treatment is necessary following adrenalectomy. In this study we developed a model based on preoperative indices for predicting postoperative adrenal insufficiency (AI) that can guide therapeutic decision-making.

Methods

A total of 27 patients with SCS who underwent adrenalectomy between August 2016 and August 2019 were enrolled and divided into AI and non-AI groups. Cox proportional hazards regression and least absolute shrinkage and selection operator analyses were performed to select relevant clinical parameters. The predictive performance of our model was evaluated by time-dependent receiver operating characteristic (ROC) curve and calibration curve analyses.

Results

Five clinical parameters (apolipoprotein A1, neutrophil–lymphocyte ratio, total cholesterol, platelet count, and homocysteine) were identified as the best predictors of replacement therapy (RT). The areas under the ROC curve for our prognostic model were 0.833, 0.945, and 0.967 for 3-, 4-, and 5-day non-(N)RT, respectively. The calibration curve of the 5 independent RT-related markers showed a good fit between nomogram-predicted probability of NRT and actual NRT, suggesting that our model has good predictive value.

Conclusions

Our prognostic nomogram can help clinicians identify patients with AI who would benefit from RT so that timely treatment can be initiated.

Keywords

Subclinical Cushing’s syndrome (SCS); Replacement therapy (RT); Adrenal insufficiency (AI); Nomogram; Receiver operating characteristic (ROC)

The Interaction of Insulin and Pituitary Hormone Syndromes

Pituitary hormone axes modulate glucose metabolism and exert direct or indirect effects on insulin secretion and function. Cortisol and growth hormone are potent insulin-antagonistic hormones. Therefore impaired glucose tolerance, elevated fasting glucose concentrations and diabetes mellitus are frequent in Cushing's disease and acromegaly. Also prolactinomas, growth hormone (GH) deficiency, hypogonadism and hypothyroidism might be associated with impaired glucose homeostasis but usually to a lesser extent. Therefore glucose metabolism needs to be closely monitored and treated in patients with pituitary adenomas. Correction of the pituitary dysfunction is frequently followed by improvement of glucose homeostasis.

The Effect of Pituitary Gland Disorders on Glucose Metabolism: From Pathophysiology to Management

This review aims to explore, present, and discuss disorders of glucose metabolism implicated in pituitary gland diseases, the appropriate interventions, as well as the therapeutic challenges that may arise. Pituitary pathologies may dysregulate glucose homeostasis, as both the excess and deficiency of various pituitary hormones can affect glucose metabolism. Increased circulating levels of growth hormone, glucocorticoids or prolactin have been shown to mainly provoke hyperglycemic states, while hypopituitarism can be associated with both hyperglycemia and hypoglycemia. Addressing the primary cause of these disorders with the use of surgery, medical treatment or radiotherapy forms the cornerstone of current management strategies. Physicians should bear in mind that some such medications have an unfavorable effect on glucose metabolism too. When unsuccessful, or until the appropriate treatment of the underlying pituitary problem, the addition of established antidiabetic therapies might prove useful. Further studies aiming to discover more accurate and effective drug preparations in combination with optimal lifestyle management models will contribute to achieving a more successful glycemic control in these patients.

Curative Effect of Catechin Isolated from Elaeagnus Umbellata Thunb. Berries for Diabetes and Related Complications in Streptozotocin-Induced Diabetic Rats Model

In this study, catechin (CTN) isolated from Elaeagnus umbellata was evaluated for in vitro antioxidant potential and inhibition of carbohydrate digestive enzymes (α-amylase and α-glucosidase). The compound was also tested for its in vivo antidiabetic potential using Sprague-Dawley rats as experimental animals. The effects of various doses of catechin in STZ (Streptozotocin) induced diabetic rats on fasting blood glucose level, body weight, lipid parameters, hepatic enzymes, and renal functions were evaluated using the reported protocols. The CTN exhibited the highest percent antioxidant for free radical scavenging activity against DPPH and ABTS free radicals, and inhibited the activity of carbohydrate digestive enzymes (with percent inhibition values: 79 ± 1.5% α-amylase and 80 ± 1.1% α-glucosidase). Administration CTN and standard glibenclamide significantly decreased the fasting blood glucose level and increased the body weight in STZ-induced diabetic rats. CTN significantly decreased the different lipid parameters, hepatic, and renal function enzyme levels along with Hb1c level in diabetic rats, while significantly increasing the high-density lipoprotein (HDL) level with values comparable to the standard glibenclamide. Further, the altered levels of glutathione and lipid peroxides of liver and kidney tissues were restored (by CTN) to levels similar to the control group. CTN significantly increased the antioxidant enzyme activities, total content of reduced glutathione, and reduced the malondialdehyde (MDA) level in rat liver and kidney tissues homogenates, and also corrected the histopathological abnormalities, suggesting its antioxidant potential.

Adipose tissue in health and disease

Adipose, or fat, tissue (AT) was once considered an inert tissue that primarily existed to store lipids, and was not historically recognized as an important organ in the regulation and maintenance of health. With the rise of obesity and more rigorous research, AT is now recognized as a highly complex metabolic organ involved in a host of important physiological functions, including glucose homeostasis and a multitude of endocrine capabilities. AT dysfunction has been implicated in several disease states, most notably obesity, metabolic syndrome and type 2 diabetes. The study of AT has provided useful insight in developing strategies to combat these highly prevalent metabolic diseases. This review highlights the major functions of adipose tissue and the consequences that can occur when disruption of these functions leads to systemic metabolic dysfunction.

The difference between steroid diabetes mellitus and type 2 diabetes mellitus: a whole-body 18F-FDG PET/CT study

AIMS

Steroid diabetes mellitus (SDM) is a metabolic syndrome caused by an increase in glucocorticoids, and its pathogenesis is unclear. ¹⁸F-FDG PET/CT can reflect the glucose metabolism of tissues and organs under living conditions. Here, PET/CT imaging of SDM and type 2 diabetes mellitus (T2DM) rats was used to visualize changes in glucose metabolism in the main glucose metabolizing organs and investigate the pathogenesis of SDM.

METHODS

SDM and T2DM rat models were established. During this time, PET/CT imaging was used to measure the %ID/g value of skeletal muscle and liver to evaluate glucose uptake. The pancreatic, skeletal muscle and liver were analyzed by immunohistochemistry.

RESULTS

SDM rats showed increased fasting blood glucose and insulin levels, hyperplasia of islet α and β cells, increased FDG uptake in skeletal muscle accompanied by an up-regulation of PI3Kp85α, IRS-1, and GLUT4, no significant changes in liver uptake, and that glycogen storage in the liver and skeletal muscle increased. T2DM rats showed atrophy of pancreatic islet β cells and decreased insulin levels, significantly reduced FDG uptake and glycogen storage in skeletal muscle and liver.

CONCLUSIONS

The pathogenesis of SDM is different from that of T2DM. The increased glucose metabolism of skeletal muscle may be related to the increased compensatory secretion of insulin. Glucocorticoids promote the proliferation of islet α cells and cause an increase in gluconeogenesis in the liver, which may cause increased blood glucose.