[Thyrotropin-secreting pituitary adenomas: clinical features and results of treatment in 45 patients]

BACKGROUND

Thyrotropin-secreting pituitary adenomas (TSH-PA) are a rare cause of thyrotoxicosis and account for 0.5-2% of all pituitary adenomas. Taking into account the rarity of the disease, it is extremely important to analyze each case of TSH-PA.

AIM

To analyze the clinical characteristics and treatment outcomes of patients with TSH-PA, as well as to determine preoperative and early postoperative factors that predict long-term remission.

MATERIALS AND METHODS

In a single-center retrospective study we analyzed clinical signs, laboratory and instrumental studies, as well as the treatment outcomes of patients with TSH-PA from 2010 to 2023. Preoperative factors, as well as TSH level measured on day 3 postoperatively, were evaluated for their ability to predict long-term remission when comparing groups of patients with and without remission.

RESULTS

The study included 45 patients with TSH-PA (14 men, 31 women), with a median age of 45 years [30; 57]. The most common clinical manifestations of TSH-PA were: cardiac arrhythmia in 37 (82.2%) patients, thyroid pathology in 27 (60%), neurological disorders in 24 (53.35%). Most PAs were macroadenomas (n=35, 77.8%). Preoperatively, 28 (77.8%) patients received somatostatin analogs, and 20 (71.4%) patients were euthyroid at the time of surgery. Surgical treatment was performed in 36 (80%) patients, postoperative remission was achieved in 31 cases (86.1%). Administration of somatostatin analogues to patients with no remission/relapse after surgery lead to the remission in 100% of cases (4/4). A 1 mm increase in PA size raised the odds of recurrence/no remission by 1.15-fold,and PA invasion during surgery - by  5.129 fold. A TSH level on day 3 postoperatively above 0.391 mIU/L (AUC, 0.952; 95% CI 0.873-1.000; standard error 0.04; p<0.001) identifies patients with relapse/absence of remission after surgical treatment (sensitivity = 100%, specificity = 88.9%).

CONCLUSION

The TSH-PA in the structure of PAs is extremely rare, and as a result, most of them are misdiagnosed and detected already at the stage of macroadenoma. The most effective method of treatment is transnasal transsphenoidal adenomectomy. Somatostatin analogues can be used as second-line therapy if surgical treatment is ineffective. We have proposed a possible model for postoperative TSH levels (>0.391 mU/l) to predict recurrence of TSH-PA, which requires validation on an expanded number of cases.

[Rare forms of hereditary endocrine neoplasia: co-existence of pituitary adenoma and pheochromocytoma/paraganglioma]

Functioning pituitary adenomas and pheochromocytomas/paragangliomas are rare in the general population. Pituitary adenomas occur in the familial setting in approximately 5% of cases, whereas pheochromocytomas/paragangliomas can be hereditary in 30-40% of cases. Hereditary syndromes associated with pituitary adenomas include multiple endocrine neoplasia types 1 and 4, familial isolated pituitary adenomas, and Carney complex. Hereditary syndromes associated with pheochromocytomas/paragangliomas and genes, mutations in which predispose to their development, are more numerous. The first clinical descriptions of the co-occurrence of pituitary adenoma and pheochromocytoma/paraganglioma in one patient date back to the mid 20th century, however delineating such a co-occurrence into a particular syndrome («3PAs» (pituitary adenoma, pheochromocytoma, paraganglioma)) was suggested only in 2015. To date, approximately 100 cases of such a co-occurrence have been described in the literature. Mutations in genes encoding subunits of succinate dehydrogenase complex II (SDHx) are revealed in the majority of cases, much less common are mutations in MAX, MEN1 and some other genes. This review summarizes the current information on the «3PAs» syndrome.

[FGF23 tumor induced osteomalacia with localization of neoplasm in the tympanic cavity]

Tumor induced osteomalacia is a rare paraneoplastic syndrome caused by mesenchymal tumors that secrete fibroblast growth factor 23 (FGF23). Patients complain of progressive bone pain, muscle weakness and brittle fractures. Delayed diagnosis of osteomalacia caused by a tumor is often found in clinical practice. When verifying the exact localization of the neoplasm, radical removal within healthy tissues is recommended. The article considers a clinical example of FGF23 tumor induced osteomalacia with localization of neoplasm in the tympanic cavity.

[FGF23 tumor induced osteomalacia]

Tumor induced osteomalacia is a rare acquired disease. The cause is a mesenchymal tumor secreting fibroblast growth factor 23 (FGF23). An excessive amount of FGF 23 disrupts the metabolism of phosphorus and vitamin D, which leads to severe paraneoplastic syndrome, manifested in the form of multiple fractures, severe pain in the bones and generalized myopathy. With oncogenic osteomalacia, a complete cure is possible with radical resection of the tumor. Unfortunately, localization, small size of formations and rare frequency of occurrence lead to the fact that the disease remains unrecognized for a long time and leads to severe, disabling consequences. A step-by-step approach to diagnosis improves treatment outcomes. First, a thorough anamnesis is collected, then functional visualization is performed and the diagnosis is confirmed by anatomical visualization of the tumor. After that, the method of choice is a surgical treatment. If resection is not possible, then conservative therapy with active metabolites of vitamin D and phosphorus salts is indicated. New therapeutic approaches, such as the antibody to FGF23 or the pan-inhibitor of receptors to FGF, are actively developing. This article provides an overview of modern approaches to the diagnosis and treatment of this disease.

[A rare case of a functioning gonadotroph tumor accompanied by erythrocytosis in an elderly man]

Functioning gonadotroph adenomas are rare pituitary tumors secreting one or two gonadotropins (follicle-stimulating hormone (FSH) and/or luteinizing hormone (LH)), which are hormonally active. In the majority of cases, gonadotroph tumors are endocrinologically "silent" and make up more than a half of non-functioning pituitary adenomas. In this article we describe a rare clinical case of LH/FSH-secreting pituitary macroadenoma with bitemporal hemianopsia in a 62-year-old man. The patient underwent transnasal transsphenoidal adenomectomy, leading to remission. The distinctive feature of this case is the presence of secondary erythrocytosis due to endogenous hyperandrogenism, which required several blood exfusions to normaliza the level of hematocrit before surgery. It is noteworthy that clinical signs of erythrocytosis were present long before visual impairment. This clinical case demonstrates difficulties in the early diagnosis of functioning gonadotroph adenomas.

[Endocrine late-effects and bone mineral density after combined treatment of malignant brain tumors in childhood and adolescence]

Обоснование

Обоснование. Внедрение в клиническую практику стандартизированных протоколов комбинированного лечения онкологических заболеваний неизбежно приводит к развитию отдаленных последствий. Поскольку у лиц, излеченных в детском и подростковом возрасте, ожидаемая продолжительность жизни велика, своевременная диагностика и коррекция отдаленных последствий противоопухолевого лечения имеют даже большее значение, чем острые осложнения химиолучевой терапии.

Цель

Цель. Изучить распространенность эндокринных нарушений, оценить распространенность и степень снижения минеральной плотности костной ткани (МПК) у лиц, перенесших комбинированное лечение злокачественных опухолей головного мозга в детском и молодом возрасте.

Материалы и методы

Материалы и методы. Проведено ретроспективное исследование с участием 59 пациентов (31 мужчина; 28 женщин), перенесших в детском и молодом возрасте оперативное лечение злокачественной опухоли головного мозга с последующей лучевой терапией в объеме краниоспинального облучения в сочетании с полихимиотерапией или без нее. I группу составили 37 пациентов, которым комбинированное лечение проводилось в возрасте от 3 до 16 лет. Во II группу были включены 22 пациента, получившие лечение в возрасте от 16 до 38 лет.

Результаты

Результаты. Недостаточность соматотропного гормона по результатам пробы с инсулиновой гипогликемией выявлена у 48 пациентов (81%), вторичная надпочечниковая недостаточность — у 22 (37%). Большая часть обследованных (33 пациента (56%)) не достигли целевого роста. Лечение рекомбинантным гормоном роста (рГР) получили только 5 человек из I группы. Проведенный корреляционный анализ показал, что возраст на момент лечения — основной фактор, влияющий на конечный рост (r=0,619; p<0,001). Выявлена высокая частота развития гипотиреоза (n=39 (66%)), гипогонадизма (19 женщин; 17 мужчин). По результатам DXA снижение МПК ≤-2,0 SD по Z-критерию в поясничном отделе позвоночника выявлено у 35 из 59 обследованных (59%). МПК у пациентов I группы была значимо ниже по сравнению с пациентами, получившими лечение в более старшем возрасте (p<0,001). Обнаружена умеренная корреляция между МПК в поясничном отделе позвоночника на момент обследования и уровнем эстрадиола в крови у женщин (r=0,596; p<0,05) и тестостерона у мужчин (r=0,472; p<0,05). Выявлена прямая зависимость МПК от возраста на момент заболевания (r=0,781; p<0,01).

Заключение

Заключение. Полученные результаты свидетельствуют о необходимости ежегодного и пожизненного наблюдения пациентов после комбинированного лечения злокачественных опухолей головного мозга на предмет выявления отдаленных последствий лечения. Высокая распространенность остеопенических состояний определяет актуальность и необходимость проведения ранней диагностики для предотвращения дальнейшей потери костной массы, снижения прочности кости и риска переломов.

[Heart arrhythmias and conduction disorders in patients with acromegaly: the role of cardiac magnetic resonance imaging]

Cardiovascular complications including arrhythmias and cardiac conduction disorders are one of the main reasons of high mortality rate in acromegaly, while they have not been well explored.

AIM

To estimate arrhythmias frequency in acromegaly, identify risk factors leading to the development of arrhythmia and cardiac conduction disorder, to determine the role of cardiac MRI in detecting structural and functional changes.

MATERIALS AND METHODS

A single-center prospective cohort study, which included 461 patients (151 men and 310 women) with acromegaly, was conducted. All the patients underwent a standard medical examination, including hormonal blood test, electrocardiogram, echocardiography, electrocardiogram daily monitoring. 18 patients with arrhythmias (11 men and 7 women) had cardiac MRI with gadolinium-based contrast.

RESULTS

The results of our research show high frequency of arrhythmias and cardiac conduction disorders in patients with acromegaly 42%. Most frequent kinds of arrhythmias and cardiac conduction disorders were sinus bradycardia 19.1% of the cases and conduction disorders of bundle branch blocks 14.5%. Men were more likely to suffer from arrhythmias and cardiac conduction disorders than women (54.2% and 37.4%, respectively,p=0.0005). Not acromegaly activity but duration of the disease was a main risk factor of arrhythmias and cardiac conduction disorders. Patients with arrhythmias had a long anamnesis of acromegaly (10 and 7 years, respectively, p=0.04). Meanwhile, cardiac conduction disorders were commonly observed in the patients who were treated with somatostatin analogs comparing to the patients who didnt undergo this therapy (50% and 38.6% respectively,p=0.004). We showed that 61% of patients with acromegaly and cardiac conduction disorders who underwent magnetic resonance imaging (MRI) had the signs of myocardial fibrosis. The value of the ejection fraction of the left ventricle according to MRI was higher than with echocardiography (p=0.04).

CONCLUSION

Arrhythmias and cardiac conduction disorders are often observed in patients with acromegaly even with remission of the disease. High risk group need careful diagnostic and monitoring approaches. Cardiac MRI is the gold standard for visualization of structural and morphological changes in the heart. Use of cardiac MRI in acromegalic patients expands our understanding of arrhythmias and cardiac conduction disorders in this disease. There are no specific laboratory markers of diffuse myocardial fibrosis, and the role of myocardial fibrosis in the occurrence of cardiac arrhythmias and conduction disorders needs further studying.

[Artificial intelligence for diagnosis of vertebral compression fractures using a morphometric analysis model, based on convolutional neural networks]

BACKGROUND

Pathological low-energy (LE) vertebral compression fractures (VFs) are common complications of osteoporosis and predictors of subsequent LE fractures. In 84% of cases, VFs are not reported on chest CT (CCT), which calls for the development of an artificial intelligence-based (AI) assistant that would help radiology specialists to improve the diagnosis of osteoporosis complications and prevent new LE fractures.

AIMS

To develop an AI model for automated diagnosis of compression fractures of the thoracic spine based on chest CT images.

MATERIALS AND METHODS

Between September 2019 and May 2020 the authors performed a retrospective sampling study of ССТ images. The 160 of results were selected and anonymized. The data was labeled by seven readers. Using the morphometric analysis, the investigators received the following metric data: ventral, medial and dorsal dimensions. This was followed by a semiquantitative assessment of VFs degree. The data was used to develop the Comprise-G AI mode based on CNN, which subsequently measured the size of the vertebral bodies and then calculates the compression degree. The model was evaluated with the ROC curve analysis and by calculating sensitivity and specificity values.

RESULTS

Formed data consist of 160 patients (a training group - 100 patients; a test group - 60 patients). The total of 2,066 vertebrae was annotated. When detecting Grade 2 and 3 maximum VFs in patients the Comprise-G model demonstrated sensitivity - 90,7%, specificity - 90,7%, AUC ROC - 0.974 on the 5-FOLD cross-validation data of the training dataset; on the test data - sensitivity - 83,2%, specificity - 90,0%, AUC ROC - 0.956; in vertebrae demonstrated sensitivity - 91,5%, specificity - 95,2%, AUC ROC - 0.981 on the cross-validation data; for the test data sensitivity - 79,3%, specificity - 98,7%, AUC ROC - 0.978.

CONCLUSIONS

The Comprise-G model demonstrated high diagnostic capabilities in detecting the VFs on CCT images and can be recommended for further validation.

[An ovarian hyperstimulation syndrome caused by gonadotropinoma in a young woman]

From 14 to 54% of all pituitary adenomas are nonfunctioning pituitary adenomas (NPAs), their prevalence is estimated as 7.041.3 cases per 100 000 population. The most common type of NPAs (73% of cases) are gonadotropinomas. In most cases, gonadotropinoma is characterized by secretion of biologically inactive hormones, so the release of gonadotropins does not lead to the development of any clinical symptoms. For this reason the diagnosis of gonadotropinomas is most often performed on the basis of immunohistochemical analysis. However, in rare cases, gonadotropinomas secrete biologically active hormones, most often follicle-stimulating (FSH). Ovarian hyperstimulation syndrome due to gonadotropin-secreting pituitary tumors occurs in about 3% of women with hormonally inactive pituitary adenomas at reproductive age and in 8% of patients with verified gonadotropinomas. This clinical case describes a young patient with a rare pathology: FSH/LH-secreting macroadenoma of the pituitary, which led to the development of ovary hyperstymulation symdrome. The diagnosis of pituitary adenoma was performed due to the identified hyperprolactinemia one month before the development of visual impairment, which can be considered a late diagnosis. Surgical treatment of gonadotropinomy was carried out successfully and without complications, remission of the disease was achieved, visual function was restored, the patient successfully became pregnant.

[Current aspects of diagnosis and treatment of adult GH-deficiency]

Adult growth hormone (GH) deficiency (AGHD) is a condition characterized by alterations in body composition, lipid and carbohydrate metabolism, bone mineral density and poor quality of life; however, clinical presentations of AGHD are mostly non-specific. Untreated AGHD is associated with increased cardiovascular morbidity and mortality. Stimulation tests are used for the diagnosis: insulin tolerance test, glucagon stimulation test, growth-hormone releasing hormone and arginine stimulation test. Moreover, in 2017 FDA approved the use of macimorelin (oral GH secretagogue) for the diagnosis of AGHD. In childhood GH-deficiency, apolipoprotein A-IV, CFHR4 (complement factor H-related protein 4) and PBP (platelet basic protein) were identified as potential biomarkers of the disease, however, this was not investigated in AGHD. GH treatment starts from the minimal dose, which allows minimizing the adverse effects. According to published meta-analyses, AGHD treatment generally does not lead to increased risk of malignancy and recurrence of sellar neoplasms in adult patients. Published data on GH receptor polymorphism associations with treatment efficacy remains controversial. Development of long-acting GH formulations is a currect perspective for the increase of treatment compliance.

[Expression of plasma microRNA in patients with acromegaly]

BACKGROUND

microRNA is a class of small non-coding RNA molecules involved in posttranscriptional regulation of gene expression. MicroRNAs are detectable in blood in stable concentrations, which makes them promising biomarkers for various diseases.

AIM

to assess plasma microRNA expression in patients with active acromegaly compared with healthy controls.

MATERIAL AND METHODS

single-center, case-control study: assessment of plasma microRNA in patients with acromegaly compared with healthy controls. Fasting blood samples were drawn and centrifuged at +5С temperature and 3000 rpm for 20 minutes, then aliquoted and frozen at 80C until further analysis. MicroRNA extraction and library preparation was done according to manufacturers instructions. Expression analysis was performed on NextSeq sequencer. Bioinformatic analysis using atropos (adapted deletion), STAR (aligning), FastQC (quality control), seqbuster/seqcluster/miRge2 (microRNA annotation, isomiR and new microRNA search, expression analysis). Primary endpoint of the study differential expression of plasma microRNA in patients with acromegaly compared with healthy controls.

RESULTS

we included 12 patients with acromegaly age 33.1 [20; 47], BMI 29.3 kg/m2 [24.0; 39.6], IGF-1 686.1 ng/mL [405.9; 1186.0] and 12 healthy subjects age 36.2 [26; 44], BMI 26.7 kg/m2 [19.5; 42.5], IGF-1 210.4 ng/mL [89.76; 281.90]; gender ratio for both groups 4 males, 8 females. The groups did not differ in gender (p=0.666), age (p=0.551) and BMI (p=0.378). We found decreased expression of four microRNAs in patients with acromegaly: miR-4446-3p 1.317 (p=0.001), miR-215-5p 3.040 (p=0.005), miR-342-5p 1.875 (p=0.013) and miR-191-5p 0.549 (p=0.039). However, none of these changes were statistically significant after adjustment for multiple comparisons (q 0.1).

CONCLUSION

we found four microRNAs, which could potentially be downregulated in plasma of patients with acromegaly. The result need to be validated using different measurement method with larger sample size.

[Hereditary Cushing's syndrome caused by primary bilateral macronodular adrenal hyperplasia due to ARMC5 mutation with concomitant primary hyperparathyroidism: the first known case in Russia]

Primary bilateral macronodular adrenal hyperplasia (PBMAH), a genetically heterogeneous disease, is a rare cause of Cushing's syndrome. Until recently, few cases were attributed to mutations in known genes. However, in 2013, ARMC5, a newly discovered tumor suppressor gene, was identified. Further studies have shown that mutations in the ARMC5 gene are found in 25-55% of all PBMAH cases. This article describes a clinical case of hereditary Cushing's syndrome caused by PBMAH in a 37-year old patient. The patient's family history is remarkable for the presence of Cushing's syndrome and PBMAH in the patient's mother. Bilateral adrenalectomy was performed as the treatment of choice. Genetic analysis using whole-exome sequencing confirmed the hereditary cause of the disease, revealing a germline heterozygous mutation in the ARMC5 gene. The patient also had concomitant mild primary hyperparathyroidism, which had not been observed before in genetic carriers with the ARMC5 mutation.

[Role of microRNA in oncogenesis of pituitary tumors and their practical significance]

Microribonucleic acids (miRNAs) are a class of noncoding RNAs that regulate posttranscriptional gene expression. These molecules are regulators of cell proliferation, metabolism, apoptosis, and differentiation. MiRNAs are not degraded by RNAases and their concentrations can be measured in different body fluids, including serum. The expression of miRNAs varies in intact tissues and tumors, including pituitary adenomas. Pituitary tumors are encountered in 22.5% of the population and, in a number of cases, may be asymptomatic, but in case of invasion or/and hormone overproduction, their clinical presentation is severe with multiple symptoms leading to disability and even death. The mechanisms for the development and progression of pituitary tumors and the markers for remission and recurrence have not been adequately investigated. This literature review discusses the biological significance of miRNAs in pituitary tumors and the potential value of circulating miRNAs as biomarkers.

Effects of endogenous hypercortisolism on bone mRNA and microRNA expression in humans

Hypercortisolism in humans suppresses osteoblastogenesis and osteoblast function through the upregulation of Wnt-signaling antagonists (sclerostin, Dkk1) and changes in microRNAs levels (miR-125b-5p, miR-218-5p, miR-34a-5p, miR-188-3p, miR-199a-5p) which are associated with mesenchymal stem-cell commitment to adipocytes or cartilage cells over the osteoblasts.

INTRODUCTION

The purpose of this study was to evaluate the responses of bone to chronic glucocorticoid (GC) excess by measuring the levels of selected mRNA and microRNA (miR) in bone samples of patients with Cushing's disease (CD).

METHODS

Bone samples were obtained during transsphenoidal adenomectomy from the sphenoid bone (sella turcica) from 16 patients with clinically and biochemically evident CD and 10 patients with clinically non-functioning pituitary adenomas (NFPA) matched by sex, age, and body mass index. Quantitative polymerase chain reactions (qPCR) were used to examine the expression of genes (mRNA and miRs) known to be involved in bone remodeling regulation based on studies in animals and cell culture.

RESULTS

Hypercortisolism was associated with the downregulation of genes involved in osteoblast function and maturation (ACP5, ALPL, BGLAP, COL1A1, COL1A2, BMP2, RUNX2, TWIST1). An excess of GC caused increased expression of Wnt-signaling antagonists (Dkk1, SOST) and changes in the levels of miRs that are known to suppress osteoblastogenesis (miR-125b-5p, miR-218-5p, miR-34a-5p, miR-188-3p, miR-199a-5p) p < 0.05, q < 0.1. Interestingly, compensatory mechanisms were found in long-term hypercortisolism: upregulation of Wnt10b, LRP5, and LRP6; downregulation of SFRP4; changes in miRs involved in osteoblastogenesis (miR-210-5p, miR-135a-5p, miR-211, miR-23a-3p, miR-204-5p); and downregulation of genes associated with osteoclastogenesis. None of these changes prevented the suppression of bone formation.

CONCLUSIONS

An excess of endogenous GC in humans suppresses bone formation through the upregulation of Wnt-signaling antagonists and dysregulation of miRs involved in mesenchymal stem-cell commitment. Both Wnt-signaling antagonists and miRs seem to be promising targets for further research in therapeutic intervention in glucocorticoid-induced osteoporosis.

[CDC73 mutations in young patients with primary hyperparathyroidism: A description of two clinical cases]

The article describes two clinical cases of severe primary hyperparathyroidism (PHPT) caused by parathyroid carcinoma in young female patients who underwent molecular genetic testing to rule out the hereditary forms of PHPT. In both patients, heterozygous germline nonsense mutations of tumor suppressor gene CDC73 encoding parafibromin (p.R91X and p.Q166X) were identified using next-generation sequencing with Ion Torrent Personal Genome Machine (Thermo Fisher Scientific - Life Technologies, USA). It is the first description of CDC73 mutations in Russia, one of the mutations is described for the first time in the world. Identification of germline mutations in the CDC73 gene in patients with PHPT necessitates regular lifelong screening for other manifestations of hyperparathyroidism-jaw tumor syndrome (HPT-JT), PHPT recurrence due to parathyroid carcinoma as well, and identification of mutation carriers among first-degree relatives.

The canonical Wnt/β-catenin pathway: From the history of its discovery to clinical application

The Wnt/β signaling pathway (Wnt-SP) is a phylogenetically ancient mechanism that regulates development and maintains tissue homeostasis through the control of cell proliferation, differentiation, migration, and apoptosis. The accurate regulation of the canonical Wnt/β-catenin signaling pathway (Wnt-SP) is critical for embryogenesis and postnatal development; and impaired signal transduction at one of its stages leads to various diseases, including organ malformations, cancers, metabolic and neurodegenerative disorders. The literature review discusses the biological role of the canonical Wnt-SP in the development of the skeleton and in the remodeling of bone tissue. The Wnt signal transmission changes observed during genetic mutations cause various human skeletal diseases. Understanding the functional mechanism involved in the development of bone abnormality could open new horizons in the treatment of osteoporosis, by affecting the Wnt-SP. The design of antibodies to sclerostin, a Wnt-SP inhibitor, is most promising now. The paper summarizes the studies that have investigated the canonical Wnt-SP and designed drugs to treat osteoporosis.

[Epigenetic Aspects of Osteoporosis]

This review describes the epigenetic regulation of osteoblastogenesis and osteoclastogenesis and its future implementation in the diagnosis and treatment of osteoporosis. A considerable part of the review is dedicated to the microRNAs (miRNAs). miRNAs are small regulatory factors that regulate gene expression, by post-transcriptional regulation of genes playing an important role in numerous cellular processes, including cell differentiation and apoptosis. Recently, a number of studies have revealed that miRNAs participate in bone homeostasis and their role in the pathogenesis of osteoporosis is practically evident. In this review, we highlight the miRNAs involved in bone remodelling and their roles in osteoporosis. miRNAs are stable molecules which make them promising potential markers for bone remodeling and osteoporosis.

Cushing’s disease: the clinical features, diagnostics, differential diagnostics, and methods of treatment

The present guidelines on diagnostics, differential diagnostics, and methods of treatment of Cushing’s disease have been developed by a group of Russian specialists.

[Carbohydrate metabolism in patients with acromegaly and Itsenko-Cushing disease]

The relevance of investigating carbohydrate metabolism (CM) in patients with acromegaly and Itsenko-Cushing disease is attributable to frequent glucose metabolic disturbances, on the one hand, and to difficulties in choosing sugar-lowering therapy in these categories of patients, on the other. The efficiency of hyperglycemia treatment in these patients may be reduced due to problems in achieving remission/cure of the underlying disease and to specific therapy favoring hyperglycemia. The top-priority tasks are to search for ways of reducing the frequency of CM abnormalities in patients with neuroendocrine diseases and to elaborate sugar-lowering therapy regimens. There is a growing interest in studies of the role of the incretin system in the pathogenesis of secondary hyperglycemias associated with neuroendocrine diseases. Nevertheless, few works have been published on this subject matter because of its novelty. There is a need for a further closer study of the specific features of incretin system function and the pharmacodynamics of incretin mimetics that are potential candidates as first-line drugs to treat secondary hyperglycemias. This paper attempts to summarize the available data obtained from studies into CM in neuroendocrine diseases.

Serum extracellular secreted antagonists of the canonical Wnt/β-catenin signaling pathway in patients with Cushing's syndrome

Patients with endogenous hypercortisolism have higher sclerostin, but do not differ in Dickkopf 1 (Dkk1) or secreted frizzled-related protein 1 (SFRP1) levels as compared to healthy control.

INTRODUCTION

Endogenous Cushing's syndrome (CS), usually affecting young and otherwise healthy patients, is a good model to validate the effects of supraphysiological levels of glucocorticoids in humans. This study evaluates circulating levels of extracellular antagonists of the Wnt/β-catenin signaling pathway (sclerostin, Dkk1, SFRP1) in patients with CS versus healthy individuals.

METHODS

Forty patients with clinically and biochemically evident CS and 40 sex-, age-, and body mass index-matched healthy subjects provided fasting serum samples for sclerostin, SFRP1 and Dkk1, along with bone turnover markers.

RESULTS

Patients with CS had higher sclerostin levels (34.5 (30.3-37.1) pmol/L) versus healthy individuals (29.9 (24.3-36.8) pmol/L) (p = 0.032). Differences in sclerostin were due to the lack of lower sclerostin values rather than an increase in protein levels above the upper limits of the healthy control. The odds of sclerostin levels being higher than 30 pmol/L were greater in patients with CS as compared with the odds in healthy subjects (odds ratio = 3.81 95 % confidence interval 1.45-10.02) (p = 0.01). It coexisted with suppressed bone formation and unchanged bone resorption markers. Dkk1, SFRP1 did not differ from the control group.

CONCLUSIONS

Of all the tested proteins (sclerostin, Dkk1, SFRP1), only sclerostin showed a significant difference when contrasting CS with healthy subjects. Hypercortisolism might prevent the down-regulation of sclerostin. Targeting sclerostin seems to be a promising therapeutic approach to treating osteoporosis in patients with CS.

Metabolic complications of endogenous Cushing: patient selection for screening

Aims: this study evaluates the most common associations of symptoms and complications in patients with Cushing’s syndrome (CS) in order to choose a potential population to be screened for CS and estimates the diagnostic accuracy of first line screening tests (cortisol, ACTH) to differentiate ACTH-ectopic CS from Cushing’s disease. Materials and Methods: The clinical data of 259 patients with proven CS during 2001–2011 was analyzed. The clinical presentations of 197 patients (159 Cushing’s disease, 28 ACTH-ectopic CS and 10 cases of benign cortisol-secreting adrenal adenoma) were compared according to the cause of hypercortisolism. ROC-analysis was performed to estimate the diagnostic accuracy of the first line tests (cortisol, ACTH) to suggest ACTH-ectopic CS. A threshold for the test with the highest area under the curves was chosen based on the maximum sum of the sensitivity and specificity. Results: The most frequent complaints were related to fatigue, muscle weakness, weight gain and changes in appearance (facial plethora and fullness, striae). Among the complications of CS the most frequent were being overweight or obese (71%), hypertension (63%), dislipoproteinemia (41%), low traumatic fractures (43%) and steroid-induced diabetes (31%). In women, 16% were older than 50, in those who were younger amenorrhea was registered in 43%. The patients with ACTH-ectopic CS had higher rate of low traumatic fractures (p=0.04), increased serum late-night cortisol, 24 hours urinary free cortisol, morning and evening ACTH and lower levels of potassium (p0.01 for all parameters). Plasma late-night ACTH measurements showed the highest AUC (0,811 (95% CI 0,712–0,909)) to differentiate ACTH-ectopic CS from Cushing’s disease. A cut off value of 108.9 pg/ml for late-night ACTH yielded a sensitivity of 60,7% and a specificity of 79%. Conclusions: patients with a coexistence of obesity, muscle weakness, fatigue, some components of metabolic syndrome and especially low traumatic fractures should be screened for CS. High plasma late night ACTH values in patients with proven CS value suggest ACTH-ectopic syndrome.

[Significance of the method of selective blood collection from the inferior petrosal sinuses for differential diagnosis of ACTH-dependent hypercorticism]

This review paper was designed to discuss the accumulated worldwide experience with selective collection of blood from the inferior petrose sinuses for the purpose of differential diagnostics of ACTH-dependent hypercorticism. The history of the development of the method is described, principal indications and contraindications to its clinical application are considered with reference to the informative value of this diagnostic tool. Possible causes of false positive and false negative results as well as complications ever reported as associated with the diagnostic procedure are discussed. Much attention is given to the comparative analysis of advantages and disadvantages of alternative techniques for blood collection and to the use of pharmaceutical agents that may increase efficiency of the method under consideration.

[The first experience with selective blood collection from the inferior petrosal sinuses in Russia (case reports)]

This paper reports two clinical cases of ACTH-dependent hypercorticism. Difficulties encountered in differential diagnosis of this condition were due to poor informative value of routine diagnostic methods. The use of selective blood collection from the inferior petrosal sinuses (for the first time in Russia) greatly facilitated the choice of the adequate treatment strategy. A detailed description of clinical features of ACTH-dependent hypercorticism in two young women is presented along with the results of laboratory and instrumental studies. Technical aspects of selective blood collection from the inferior petrosal sinuses in conjunction with the desmopressin stimulation protocol are considered. Indications for the use of this diagnostic method under real clinical conditions are proposed. Results of the study are discussed with reference to the treatment strategy chosen for the management of ACTH-dependent hypercorticism and the outcome of surgical intervention.

[Role of exercises in health and in diabetes mellitus]

Exercise has been seen as beneficial in the treatment of diabetes. This therapy was recognized as useful and was widely used by physicians of the 19th and early 20th centuries. Following the discovery of insulin, many researchers recommended physical activity as one of the main principles for diabetes management.Currently, due to the development of new opportunities in the treatment of diabetes mellitus, physical activity is not considered as the only necessary part of the impact on each patient with diabetes, as it was in the past. Over the past 2 decades, many studies using new technologies have explored the relationship between physical fitness and metabolic control of diabetes. With the publication of new clinical reviews, it has become increasingly apparent that exercise can be a therapeutic tool in different patients with diabetes or the risk of developing diabetes, but their effect, like any other therapy, should be understandable. From a practical point of view, this means that doctors must understand and analyze both the risk and the gain from physical activity for each individual patient. On the other hand, it is generally accepted that physical exercise is associated with an improvement in the quality of life and has a beneficial effect on the cardiovascular system; therefore, metabolic control should not be just one criterion in assessing the beneficial effects of training programs for patients with diabetes. It is important to recommend optimal training for patients to improve glycemic control and the state of the cardiovascular system, or to help select appropriate therapy if the patient independently chooses the type of exercise.