Structure and Function of Somatostatin and its Receptors in Endocrinology.

Somatostatin analogs, such as octreotide (OCT), lanreotide, and pasireotide, which function as somatostatin receptor ligands (SRLs), are the main drugs used for the treatment of acromegaly. These ligands are also used as important molecules for radiation therapy and imaging of neuroendocrine tumors (NETs). Somatostatin receptors (SSTRs) are canonical G protein-coupled proteins (GPCRs) that play a role in metabolism, growth, and pathological conditions such as hormone disorders, neurological diseases, and cancers. Cryogenic electron microscopy (cryo-EM) combined with the protein structure prediction platform AlphaFold has been used to determine the three-dimensional structures of many proteins. Recently, several groups published a series of papers illustrating the three-dimensional structure of SSTR2, including that of the inactive/activated SSTR2-G protein complex bound to different ligands. The results revealed the residues that contribute to the ligand binding pocket and demonstrated that Trp8-Lys9 (the W-K motif) in somatostatin analogs is the key motif in stabilizing the bottom part of the binding pocket. In this review, we discuss the recent findings related to the structural analysis of SSTRs and SRLs, the relationships between the structural data and clinical findings, and the future development of novel structure-based therapies.

Epicardial adipose tissue volume highly correlates with left ventricular diastolic dysfunction in endogenous Cushing's syndrome.

BACKGROUND: Cushing's syndrome (CS) is associated with increased risk for heart failure, which often initially manifests as left ventricular diastolic dysfunction (LVDD). In this study, we aimed to explore the potential risk factors of LVDD in CS by incorporating body composition parameters. METHODS: A retrospective study was conducted on patients diagnosed with endogenous CS no less than 18 years old. The control group consisted of healthy individuals who were matched to CS patients in terms of gender, age, and BMI. LIFEx software (version 7.3) was applied to measure epicardial adipose tissue volume (EATV) on non-contrast chest CT, as well as abdominal adipose tissue and skeletal muscle mass at the first lumbar vertebral level. Echocardiography was used to evaluate left ventricular (LV) diastolic function. Body compositions and clinical data were examined in relation to early LVDD. RESULTS: A total of 86 CS patients and 86 healthy controls were enrolled. EATV was significantly higher in CS patients compared to control subjects (150.33 cm3 [125.67, 189.41] vs 90.55 cm3 [66.80, 119.84], p < 0.001). CS patients had noticeably increased visceral fat but decreased skeletal muscle in comparison to their healthy counterparts. Higher prevalence of LVDD was found in CS patients based on LV diastolic function evaluated by E/A ratio (p < 0.001). EATV was proved to be an independent risk factor for LVDD in CS patients (OR = 1.015, 95%CI 1.003-1.026, p = 0.011). If the cut-point of EATV was set as 139.252 cm3 in CS patients, the diagnostic sensitivity and specificity of LVDD were 84.00% and 55.60%, respectively. CONCLUSION: CS was associated with marked accumulation of EAT and visceral fat, reduced skeletal muscle mass, and increased prevalence of LVDD. EATV was an independent risk factor for LVDD, suggesting the potential role of EAT in the development of LVDD in CS.

This study explored the potential risk factors of LVDD in endogenous CS by incorporating body composition parameters. EATV was identified as an independent risk factor for LVDD. Targeted therapeutic interventions to reduce excessive cortisol-induced EAT accumulation may be promising to mitigate the risk of LVDD development in patients with CS.

Retrospective analysis of the outcomes of endoscopic transsphenoidal surgery for Cushing's disease.

Background: The first-line surgical management of an adrenocorticotropic hormone (ACTH)--secreting pituitary adenoma causing Cushing's disease (CD) is endoscopic transsphenoidal resection of the tumor. This study was performed to assess postoperative (postop) complications and remission in endoscopic surgically resected cases of CD. Methods: Data of patients who underwent endoscopic transsphenoidal surgery (ETSS) for CD were collected from the neurosurgery department at a tertiary care center in a retrospective manner from January 2015 to February 2022 and analyzed. Postoperative remission was categorized as - early morning serum cortisol <138 nmol/L within 7 days of the surgery, as per the Endocrine Society Guidelines, with significant clinical improvement in features of hypercortisolism in the operated patient and strict cutoff rate of <50 nmol/L at postop day 3 was also utilized, to look for the early identification of remission. Results: A total of 41 patients were identified who underwent 44 ETSS during the same timeframe. Preoperative magnetic resonance imaging localized an adenoma in all 41 patients, out of which 32 were microadenoma, and nine were macroadenoma (2 with cavernous sinus invasion). Intrapetrosal sinus sampling was performed in 35 (85%) patients. The rate of remission for the initial surgery was 85.4% using the standard criteria and 68.3% using strict criteria. Three patients underwent early repeat surgery for the persistent disease as the day 3 cortisol was high (306-555 nmol/L). Once the outcome of this surgery was also included, the overall rate of remission was 90.2% (37/41). None of the patients had meningitis, cerebrospinal fluid leakage, visual deterioration, or vascular injury. Permanent and transient diabetes insipidus (DI) occurred in 9.75% and 26.8% following the first ETSS, respectively. We also noted a single case of CD recurrence in 9 months during the total follow-up period of 84 months. Conclusion: ETSS has satisfactory rates of remission for the primary treatment of CD, with rates being higher for microadenomas. A long follow-up period is needed to assess the rates of recurrence. Patients must be counseled regarding the risk of postop DI, whether transient or permanent, as a possible complication.

Efficacy and Safety of Osilodrostat in Managing Cushing's Syndrome: A Systematic Review and Meta-Analysis.

No meta-analysis has holistically analysed and summarized the efficacy and safety of osilodrostat, a novel dual 11ß-hydroxylase (cytochrome P450 family 11 subfamily B member 1 [CYP11B1]) and 18-hydroxylase (aldosterone synthase, CYP11B2) inhibitor in managing Cushing's syndrome (CS). We undertook this meta-analysis to address this knowledge gap. Electronic databases were searched for randomized controlled trials (RCTs) involving patients with CS receiving osilodrostat in the intervention arm. The primary outcome was to evaluate changes in urine free cortisol (UFC) levels. Secondary outcomes were to evaluate alterations in cortisol levels, androgen levels, mineralocorticoid levels, and adverse events. From initially screened 109 articles, data from 2 RCTs involving 144 patients was analysed. After 8-12 weeks of therapy, the odds of achieving a normal 24-hour UFC was higher in patients receiving oslidrostat as compared to placebo. [odds ratio (OR) 21.94 (95% CI: 8.53-56.43); P < 0.00001; I2 = 0%]. The occurrence of adverse events [OR 1.35 (95% CI: 0.52-3.53); P = 0.54; I2 = 0%; low heterogeneity (LH); High certainty of evidence (HCE)], serious adverse events (SAEs) [OR 1.32 (95% CI: 0.30-5.79); P = 0.72; I2 = 0%; LH; HCE], adrenal insufficiency [OR 5.38 (95% CI: 0.91-31.78); P = 0.06; I2 = 0%; LH; HCE], headache [OR 0.98 (95% CI: 0.35-2.76); P = 0.97; I2 = 0%; LH; HCE], hyperandrogenism [OR 3.68 (95% CI: 0.59-22.80); P = 0.16; I2 = 0%; LH; HCE] and deaths [OR 0.32 (95% CI: 0.01-8.00); P = 0.48; I2 = 0%; LH; HCE] was comparable among the groups. The occurrence of nausea [OR 4.25 (95% CI: 1.26-14.30); P = 0.02; I2 = 0%; LH] and arthralgia [OR 6.54 (95% CI: 1.64-26.13); P = 0.008; I2 = 0%; LH; HCE] was significantly higher in the osilodrostat group as compared to placebo. Osilodrostat has good efficacy and safety in CS and was well tolerated over 48 weeks of use.

Paraneoplastic Syndrome in Adrenocortical Carcinoma: The Unexpected Mime.

Adrenocortical carcinoma (ACC) is a malignancy of the adrenal cortex with a high morbidity and mortality. More than half of the cases are functional tumors. As different hormones can be co-secreted above physiologic levels, it causes a very broad variety of symptoms and makes differentiating from more common entities hard. Here we present a case of a patient with a newly diagnosed ACC who initially presented with acute pulmonary embolism and recurrent deep vein thromboses (DVT) in the setting of hypercortisolism. Imaging showed a left adrenal mass invading adjacent structures including a nonocclusive thrombus in the left renal vein. Intravenous anticoagulation and thrombectomy were initially performed, followed by removal of the tumor and adjacent metastatic disease. Pathology confirmed ACC. The patient underwent left adrenalectomy, left nephrectomy, splenectomy, distal pancreatectomy, and caval thrombectomy with inferior vena cava (IVC) filter placement. Intravenous anticoagulation and glucocorticoid replacement were also administered as part of the treatment plan. Unfortunately, the patient had multiple episodes of bleeding and thrombosis and was eventually discharged to hospice care. DVT in the setting of ACC can be caused by increased hypercoagulability from hypercortisolism, direct venous thrombosis, or vascular invasion. Thrombosis, especially in the inferior vena cava, has been associated with poor prognosis and survival rates. Clinicians should be aware of this rare complication given its immediate therapeutic repercussions and prognostic value.

Evaluating the efficacy of surgical and conservative approaches in mild autonomous cortisol secretion: a meta-analysis.

Introduction: The management of Mild Autonomous Cortisol Secretion (MACS) remains a topic of debate among clinicians, with differing opinions on the effectiveness of surgical intervention compared to conservative treatment methods. This meta-analysis provides a comprehensive assessment of available literature to determine the most effective approach for treating this condition. Methods: On December 1, 2023, an exhaustive literature search of English databases Embase, PubMed, the Cochrane Library, Scopus, Web of Science, as well as the Chinese databases China HowNet, Wanfang Database, SinoMed Database, and Weipu Database using the keywords "Mild Autonomous Cortisol Secretion", "Subclinical Cushing's Syndrome", "Subclinical Hypercortisolism", "Mild Cortisol Autonomous Secretion", "Adrenal Incidentaloma", "Surgical Treatment" and "Adrenalectomy". The data were statistically analyzed using STATA version 15.0. Results: In this comprehensive analysis involving 629 patients with MACS, the therapeutic efficacy of adrenalectomy was evident. The meta-analysis results indicate that compared to conservative treatment, surgical intervention more effectively improves obesity indicators in patients: waist circumference (SMD=-0.62, 95% CI: -1.06 to -0.18), BMI (SMD=-0.41, 95% CI: -0.62 to -0.20), enhances glycemic control: fasting blood glucose (SMD=-0.47, 95% CI: -0.68 to -0.26), glycated hemoglobin (SMD=-0.66, 95% CI: -0.95 to -0.38), improves lipid metabolism: triglycerides (SMD=-0.45, 95% CI: -0.73 to -0.16), lowers blood pressure: systolic blood pressure (SMD=-1.04, 95% CI: -1.25 to -0.83), diastolic blood pressure (SMD=-0.89, 95% CI: -1.12 to -0.65), and ameliorates hormonal metabolic disorder: 24h urinary free cortisol (SMD=-1.10, 95% CI: -1.33 to -0.87), ACTH (SMD=2.30, 95% CI: 1.63 to 2.97). All these differences are statistically significant. Conclusion: This meta-analysis shows that, compared to conservative treatment, surgical treatment is more effective in improving obesity indicators, glycemic control, lipid metabolism, reducing blood pressure, and ameliorating hormonal metabolic disorders in patients with MACS. These statistically significant results highlight the importance of considering surgical intervention in the management of patients with MACS. Systematic review registration: https://www.crd.york.ac.uk/prospero, identifier CRD42023492527.

Adrenocorticotropic Hormone Producing Pituitary Carcinoma in the Falx Cerebri, Retroclival Region, Ethmoidal Cells, and Other Locations.

Pituitary carcinoma is a condition defined by metastasis of a pituitary tumor to a distant location, and it is a very rare type of adenohypophyseal tumor. We present a case of a 29-year-old female who was followed up in our Endocrinology Department. Past medical history included the diagnosis of Cushing disease and transsphenoidal tumor resection at 12 years of age, followed by transcranial resection two years later because of persistently elevated adrenocorticotropic hormone (ACTH). Despite the surgical management, the patient persisted with increased ACTH and hypercortisolism, and, thus, bilateral adrenalectomy was performed a year later. Two years after the procedure, the patient presented with a newly diagnosed pituitary macroadenoma, and the diagnosis of Nelson syndrome was made. Linear accelerator radiotherapy was given, which reduced the size of the tumor. Later, several imaging studies showed multiple lesions on the falx cerebri, posterior clinoid process, retroclival region, cerebellopontine angle, pterygopalatine fossa, infratentorial region, and posterior ethmoidal cells. Biopsy and immunohistochemistry of the falx cerebri lesions described ACTH-producing pituitary adenocarcinoma. Treatment was given with intramuscular octreotide, dabrafenib, and trametinib. Despite persistently elevated ACTH levels, the patient has since remained clinically stable, without new development or worsening of symptoms. There are three unique aspects of our case. First, we reported an unusual presentation of this disease, since the patient in our case was a female with an early age of onset. Second, this is the first reported case demonstrating pituitary carcinoma in the falx cerebri. Third, the prognosis of pituitary carcinoma is usually very poor, and mortality is extremely high; however, the patient in our case has been followed up for seven years since the diagnosis of the metastatic lesions and has remained clinically stable.

Comparable cognitive impairment was detected in MACS and CS and alleviated after remission of hypercortisolism in MACS.

Context: Few studies have directly compared the cognitive characteristics of patients with mild autonomous cortisol secretion (MACS) and Cushing's syndrome (CS). The effect of surgical or conservative treatment on cognitive function in patients with MACS is still unclear. Objective: To compare the differences in cognitive function between patients with MACS and CS and evaluate the effect of surgery or conservative treatment on cognitive function. Methods: We prospectively recruited 59 patients with nonfunctional adrenal adenoma (NFA), 36 patients with MACS, and 20 patients with adrenal CS who completed the global cognition and cognitive subdomains assessments. Seventeen MACS patients were re-evaluated for cognitive function after a 12-month follow-up period; of these, eleven underwent laparoscopic adrenalectomy and six received conservative treatment. Results: Patients with MACS and CS performed worse in the global cognition and multiple cognitive domains than those with NFA (all P<0.05). No statistical difference was found in cognitive functions between patients with MACS and CS. Logistic regression analysis showed that patients with MACS (odds ratio [OR]=3.738, 95% confidence intervals [CI]: 1.329-10.515, P=0.012) and CS (OR=6.026, 95% CI: 1.411-25.730, P=0.015) were associated with an increased risk of immediate memory impairment. Visuospatial/constructional, immediate and delayed memory scores of MACS patients were significantly improved at 12 months compared with pre-operation in the surgical treatment group (all P<0.05), whereas there was no improvement in the conservative treatment group. Conclusion: Patients with MACS have comparable cognitive impairment as patients with CS. Cognitive function was partially improved in patients with MACS after adrenalectomy. The current data support the inclusion of cognitive function assessment in the clinical management of patients with MACS.

Chronic hypercortisolism disrupts the principal functional gradient in Cushing's disease: A multi-scale connectomics and transcriptomics study.

Cushing's disease (CD) represents a state of cortisol excess, serving as a model to investigate the effects of prolonged hypercortisolism on functional brain. Potential alterations in the functional connectome of the brain may explain frequently reported cognitive deficits and affective disorders in CD patients. This study aims to elucidate the effects of chronic hypercortisolism on the principal functional gradient, which represents a hierarchical architecture with gradual transitions across cognitive processes, by integrating connectomics and transcriptomics approaches. Utilizing resting-state functional magnetic resonance imaging data from 140 participants (86 CD patients, 54 healthy controls) recruited at a single center, we explored the alterations in the principal gradient in CD patients. Further, we thoroughly explored the underlying associative mechanisms of the observed characteristic alterations with cognitive function domains, biological attributes, and neuropsychiatric representations, as well as gene expression profiles. Compared to healthy controls, CD patients demonstrated changes in connectome patterns in both primary and higher-order networks, exhibiting an overall converged trend along the principal gradient axis. The gradient values in CD patients' right prefrontal cortex and bilateral sensorimotor cortices exhibited a significant correlation with cortisol levels. Moreover, the cortical regions showing gradient alterations were principally associated with sensory information processing and higher-cognitive functions, as well as correlated with the gene expression patterns which involved synaptic components and function. The findings suggest that converged alterations in the principal gradient in CD patients may mediate the relationship between hypercortisolism and cognitive impairments, potentially involving genes regulating synaptic components and function.

Diagnostic and management challenges in paediatric Cushing's syndrome.

OBJECTIVE: Cushing syndrome (CS) is the result of chronic exposure to glucocorticoid excess. CS in children is most often caused by the administration of exogenous steroids. Endogenous CS is rare in the paediatric population and is caused mainly by tumours of the pituitary and adrenal glands, with ectopic sources being extraordinarily rare before the age of 18 years. In addition, children and young adults with CS present with different epidemiology, management issues, prognosis and outcomes than older adult patients. This complex disorder needs early diagnosis and management to avoid the significant morbidity and even mortality that can result from chronic untreated CS. METHODS: In this review, we present the complex case of a 7-year-old boy with CS that highlights the diagnostic and management challenges of paediatric CS patients, including the considerations for genetic predisposition and life-long consequences of CS in children and young adults. RESULTS: The diagnostic protocols for the evaluation of CS have been devised for adults and tested predominantly on adults. In this review, we discuss necessary modifications so that the testing can be adjusted for use in children. Additionally, pituitary adenomas in children are generally smaller and thus more difficult to recognize on pituitary imaging. CONCLUSIONS: The management of the case and its complexities underline the need for children with CS to be managed in a centre with experienced paediatric endocrinologists and skilled neurosurgeons both for their initial diagnosis and treatment as well as for their long-term follow-up and management.

Circulating miR-28-5p is overexpressed in patients with sarcopenia despite long-term remission of Cushing's syndrome: a pilot study.

Introduction: Patients with Cushing's syndrome (CS) in remission show sustained fatigue, myopathy, and an increased prevalence of sarcopenia. The mechanisms that determine these persistent muscle problems are not well known. We aimed to identify circulating microRNAs (miRNAs) with differential expression that could be potential biomarkers for the diagnosis and/or prognosis in CS. Patients and methods: Thirty-six women in sustained remission for 13 ± 7 years (mean ± SD) from CS, with a median age (IQ range) of 51 (45.2-60) years and mean ± SD BMI of 27 ± 4 Kg/m2, and 36 matched healthy controls were investigated. In 7 patients sarcopenia was present according to the European Working Group on Sarcopenia in Older People (EWGSOP) criteria. Small RNA libraries were generated and indexed using a modified Illumina TruSeq small RNA-sequencing protocol. MiRNAs were identified in plasma using bioinformatic analysis, and validation was carried out using RT-qPCR. For the validation, Taqman probes were performed on QuantStudio 5 equipment (Applied Biosystems). Results: In a first discovery group using RNA-sequencing, plasma samples of 18 CS patients and 18 healthy subjects were investigated; circulating miR-28-5p, miR-495-3p and miR-654-5p were upregulated in CS patients as compared with controls (p<0.05). In a validation study of the 3 upregulated miRNAs in 36 patients and 26 controls, no differences were observed by RT-qPCR; however, the expression of circulating miR-28-5p was upregulated in CS patients with sarcopenia as compared with those without (AUC for fold-change in the ROC analysis, 0.798; p=0.0156). The optimized cut-off value for miR-28-5p to identify CS patients with sarcopenia was 3.80, which yielded a sensitivity of 86% and a specificity of 69%. Conclusion: MiR-28-5p, a muscle-specific microRNA involved in myotube proliferation and differentiation in vivo, may serve as an independent non-invasive biomarker for identifying CS patients at high-risk of sarcopenia despite biochemical remission.

The effect of obesity on the outcomes of laparoscopic adrenal surgery in patients with Cushing syndrome.

Purpose: The aim of this study is to investigate the effect of obesity on the results of laparoscopic adrenal surgery in patients with Cushing syndrome. Methods: This retrospective study was performed in Department of General Surgery at Erciyes University School of Medicine between January 2010 and January 2023. Our analysis included Cushing syndrome patients who underwent unilateral laparoscopic adrenalectomy (LA) with the transabdominal lateral approach. All patients were evaluated in terms of age, sex, tumor diameter, body mass index (BMI), American Society of Anesthesiologists physical status classification, morbidities, surgery history, tumor side, operative time, conversion to open surgery, complications, and length of hospital stay. Results: A total of 90 patients (75 females and 15 males) underwent a transperitoneal LA. Patients were divided into 2 groups according to their BMI: obese group (≥30 kg/m2; n = 53, 58.8%) and nonobese group (<30 kg/m2; n = 37, 41.2%). All patients were classified into 3 subgroups: obese patient group, BMI ≥30-39 kg/m2 (n = 23); morbidly obese patient group, BMI ≥40 kg/m2 (n = 14); and nonobese patient group, BMI <30 kg/m2 (n = 53). There was no significant difference in intraoperative complications, conversion to open surgery, operative time, or length of hospital stay between the groups. Only conversion to open surgery was a risk factor for postoperative complications in univariate and multivariate analyses (odds ratio, 15.4; 95% confidence interval, 1.277-185.599; P = 0.031). Conclusion: Our results showed that LA is safe and effective in patients with Cushing syndrome with morbid obesity, allowing acceptable morbidity and length of hospital stay.

Adipose tissue in health and disease.

This Virtual Special Issue on Adipose tissue in health and disease features 26 original articles from different international contexts. It expands our understanding of the adipose tissue as an essential organ involved in relevant physiological functions such as reproduction, metabolism, energy balance, endocrinology, circadian rhythm, and inflammation. The focus is on the adipose tissue as a common key mediator of different severe metabolic pathologies including insulin resistance, liver diseases, cardiometabolic diseases, diabetes, lipodystrophy, Cushing's syndrome, obesity, and polycystic ovary syndrome. This adipose tissue-associated diseases are linked with a high mortality and increased health care costs worldwide. Thus, the 26 contributions of this Special Issue aim at identifying molecular mechanisms by which the adipose tissue is involved in the progression of its associated pathologies. Deeper understanding of these mechanisms in health and disease and the context-dependent parameters shaping them, is likely key to decipher the full potential of the adipose tissue for novel therapeutic approaches and strategies for managing complications associated with obesity and the metabolic syndrome.

Ectopic Cushing Syndrome Secondary to Diffuse Idiopathic Neuroendocrine Cell Hyperplasia-A Report of 2 Cases.

Ectopic ACTH secretion (EAS) accounts for 10% to 20% of all Cushing syndrome cases. Diffuse intrapulmonary neuroendocrine cell hyperplasia (DIPNECH), a poorly understood lung disease, is characterized by abnormal proliferation of neuroendocrine cells in the bronchial mucosa. It is thought to be a precursor of pulmonary carcinoid and has been associated with EAS in a handful of cases. We present 2 patients with clinical, radiological, and pathological features of DIPNECH who presented with florid Cushing syndrome secondary to EAS evidenced by rapid onset of symptoms, elevated plasma ACTH, and cortisol levels, and failed high-dose dexamethasone suppression testing. Treatment of hypercortisolism included excision of the involved lung and medical therapy with steroidogenesis inhibitors. Despite the aggressive initial management, hypercortisolism persisted. This case series highlights the importance of considering DIPNECH as a cause for Cushing syndrome in the appropriate clinical scenario and underscores the likelihood that surgery may not be curative because of the diffuse nature of this disease. Given the high mortality associated with EAS, prompt medical therapy, appropriate prophylaxis, and bilateral adrenalectomy can be lifesaving measures when initial surgery fails.

Glucocorticoid modulates oxidative and thermogenic function of rat brown adipose tissue and human brown adipocytes.

Chronic and excessive glucocorticoid (GC) exposure can cause Cushing's syndrome, resulting in fat accumulation in selected body areas. Particularly in the brown adipose tissue (BAT), GC acts negatively, resulting in whitening of the tissue. We hypothesized that dysregulation of microRNAs by GC could be an additional mechanism to explain its negative actions in BAT. Male Wistar rats were divided into two groups: (1) Control sham and (2) GC group that was administered dexamethasone 6.25 mg/200 µL via osmotic pump implantation over 28 days. After this period, the animals were euthanized and BAT tissue was properly stored. Human fat cells treated with dexamethasone were used to translate the experimental results found in animals to human biology. GC-treated rat BAT presented with large lipid droplets, severely impaired thermogenic activation, and reduced glucose uptake measured by 18F-FDG PET/CT. GC exposure induced a reduction in the mitochondrial OXPHOS system and oxygen consumption. MicroRNA profiling of BAT revealed five top-regulated microRNAs and among them miR-21-5p was the most significantly upregulated in GC-treated rats compared to the control group. Although upregulation of miR-21-5p in the tissue, differentiated primary brown adipocytes from GC-treated rats had decreased miR-21-5p levels compared to the control group. To translate these results to the clinic, human brown adipocytes were treated with dexamethasone and miR-21-5p inhibitor. In human brown cells, inhibition of miR-21-5p increased brown adipocyte differentiation and prevented GC-induced glucose uptake, resulting in a lower glycolysis rate. In conclusion, high-dose GC therapy significantly impacts brown adipose tissue function, with a notable association between glucose uptake and miR-21-5p.

Assessment of aortic perivascular and renal sinus fat in endogenous cortisol excess of different etiology.

OBJECTIVE: Endogenous cortisol excess is known to affect body fat distribution. Ectopic fat is the accumulation of triglycerides in non-adipose tissue regions that normally contain little fat. The aim of study was to investigate the amount of ectopic fat in aortic perivascular and renal sinus fat of patients with endogenous cortisol excess and its relationship with their comorbitidies and laboratory findings. DESIGN: A total of 119 patients, including 16 patients with pituitary Cushing's disease (CD), 21 patients with adrenal Cushing's syndrome (CS), 34 patients with mild autonomous cortisol secretion (MACS), and 48 patients with nonfunctioning adrenal adenomas were enrolled in this retrospective study. Aortic perivascular fat and renal sinus fat were evaluated with magnetic resonance imaging. RESULTS: It was determined that the amount of aortic perivascular fat was increased in patients with CD (P = 0.01). The linear regression analysis showed that the amount of perivascular fat was associated with triglyceride levels and cortisol levels after the 1 mg dexamethasone suppression test as well as with gender (P < 0.01). Renal sinus fat measurements were similar in the groups (P > 0.05). After adjusting for age, sex, and BMI, perivascular fat was found to be higher in pituitary the CD than in the MACS and the nonfunctioning adenoma groups, and renal sinus fat was seen to be higher in pituitary the CD than in the MACS groups (P < 0.05). Patients with diabetes mellitus had an increased amount of renal sinus fat (P = 0.008). CONCLUSION: The amount of perivascular and renal sinus fat may increase in patients with CD. Further studies are needed to elucidate ectopic fat distribution in patients with endogenous cortisol excess.

Spontaneous Cushing's Disease Remission Induced by Pituitary Apoplexy.

Spontaneous remission of Cushing's disease (CD) is uncommon and often attributed to pituitary tumor apoplexy. We present a case involving a 14-year-old female who exhibited clinical features of Cushing's syndrome. Initial diagnostic tests indicated CD: elevated 24h urinary cortisol (235 µg/24h, n < 90 µg/24h), abnormal 1 mg dexamethasone overnight test (cortisol after 1 mg dex 3.4 µg/dL, n < 1.8 µg/dL), and elevated adrenocorticotropic hormone concentrations (83.5 pg/mL, n 10-60 pg/mL). A pituitary adenoma was suspected, so a nuclear MRI was performed, with findings suggestive of a pituitary microadenoma. The patient was referred for a transsphenoidal resection of the microadenoma. While waiting for surgery, the patient presented to the emergency department with a headache and clinical signs of meningism. A computed axial tomography of the central nervous system was performed, and no structural alterations were found. The symptoms subsided with analgesia. One month later, she presented again to the emergency department with clinical findings of acute adrenal insufficiency (cortisol level of 4.06 µg/dL), and she was noted to have spontaneous biochemical remission associated with the resolution of her symptoms of hypercortisolism. For that reason, spontaneous CD remission induced by pituitary apoplexy (PA) was diagnosed. The patient has been managed conservatively since the diagnosis and remains in clinical and biochemical remission until the present time, after 10 months of follow-up. There are three unique aspects of our case: the early age of onset of symptoms, the spontaneous remission of CD due to PA, which has been rarely reported in the medical literature, and the fact that the patient presented a microadenoma because there are fewer than 10 clinical case reports of PA associated with microadenoma.

Understanding negative feedback: Changes in high-molecular-weight adrenocorticotropic hormone in adrenocorticotropic hormone-independent Cushing's syndrome.

Cushing's syndrome is characterized by chronic glucocorticoid oversecretion and diverse clinical manifestations. Distinguishing between adrenocorticotropic hormone (ACTH)-independent and ACTH-dependent forms is crucial for determining treatment options. Plasma ACTH levels aid in the differential diagnosis, with undetectable or low levels suggesting ACTH-independent hypercortisolemia. ACTH is derived from pro-opiomelanocortin, and its processing involves prohormone convertase 1/3. High-molecular-weight ACTH is generally found in ACTH-producing pituitary tumors and ectopic ACTH syndrome. The mechanism of negative feedback and the process of high-molecular-weight ACTH alternation during ACTH-independent Cushing's syndrome remain unclear. A 40-year-old woman with hypertension and multiple fractures developed symptoms suggestive of Cushing's syndrome. Computed tomography revealed a left adrenocortical tumor along with atrophy of the right adrenal gland. ACTH levels were undetectable at the previous clinic, indicating ACTH-independent Cushing's syndrome. However, subsequent measurements at our hospital revealed non-suppressed ACTH (18.1 pg/mL), prompting further investigation. Gel exclusion chromatography confirmed the presence of high-molecular-weight ACTH. Metyrapone treatment decreased the cortisol levels. In this situation, in which ACTH levels should be elevated, a decrease in high-molecular-weight ACTH levels was observed. Histological findings revealed cortisol-producing adenoma without ACTH expression. This case highlights the importance of assay differences in evaluating ACTH concentrations and introduces a novel finding of circulating high-molecular-weight ACTH. The observed decline in high-molecular-weight ACTH levels suggests a potential time lag in the negative feedback within the hypothalamic-pituitary-adrenal axis exhibited by glucocorticoids. This temporal aspect of the regulation of ACTH-related molecules warrants further exploration to enhance our understanding of the hypothalamic-pituitary-adrenal axis feedback mechanism.

Left ventricular subclinical systolic myocardial dysfunction assessed by speckle-tracking in patients with Cushing's syndrome.

PURPOSE: Two-dimensional speckle tracking echocardiography is a novel ultrasound technique, which can detect early subclinical myocardial dysfunction with high sensitivity. The purpose of this study was to explore the value of speckle tracking echocardiography in the evaluation of subclinical myocardial injury in patients with Cushing's syndrome. METHODS: 35 patients with Cushing's syndrome and 29 healthy controls matched for age, sex, BMI, and systolic blood pressure were included in the study. All subjects were assessed using both conventional Doppler echocardiography and speckle tracking echocardiography. Among patients, they were further divided into inactive group (n = 7) and active group (n = 28) based on cortisol levels. Trend analysis was used among patients in different disease activity. Correlation analysis and linear regression analysis were used to explore influence factors related to subclinical myocardial dysfunction. RESULTS: Left ventricular ejection fraction value showed no statistical difference between patients Cushing's syndrome and control group. However, GLS and LVSD, show significant differences in Cushing's syndrome group. Also, among active Cushing's syndrome group, inactive Cushing's syndrome group and control group, GLS (-15.4 ± 3.0 vs -18.1 ± 3.1 vs-19.4 ± 2.4, P < 0001) and LVSD (48.9 ± 21.5 vs 43.5 ± 17.9 vs 28.5 ± 8.3, P < 0001) changed significantly with the disease activity status. In addition, GLS and LVSD were both linearly corrected with 24-hour urinary cortisol level. CONCLUSION: GLS and LVSD are sensitive parameters in detecting and monitoring subclinical myocardial systolic dysfunction in patients with Cushing's syndrome. Myocardial injury is linearly correlated with cortisol level, which can be partially reversed after the biochemical control of cortisol.