Рис. 1. Механизм антидиуретического действия АВП.

Central diabetes insipidus is a severe disease with disturbance of arginine vasopressin secretion, which leads to excretion of large amounts of hypotonic urine. The polyuria-polydipsia syndrome is essential as a clinical presentation and high impact condition. Desmopressin, a synthetic analog of arginine vasopressin, is used to compensate a water-electrolyte balance is available in forms of tablets and intranasal spray. Free drug choice is obligated for proper treatment

The prevalence of vitamin D deficiency in Russian Federation

In this review, we discuss the main reasons for the vitamin D insufficiency in Russian Federation, as well as data on the prevalence of vitamin D deficiency among various population groups and regions, which confirm the widespread prevalence of vitamin D deficiency in the country. The discussed data suggest that the current vitamin D insufficiency in Russian population (reduced levels of 25(OH)D occurs in 50 - 94% of general population) is due to both a low level of its endogenous synthesis and insufficient intake from food : the territory of the country is located in a zone of low insolation, and at the same time, the main natural sources of vitamin D (sea fish of fatty varieties) and fortified with vitamin D products are very limited in the diet of the population. Taking measures to improve the status of vitamin D and maintaining the optimal serum levels of 25(OH)D in children and adults, adequate vitamin D intake will improve the condition of the musculoskeletal system, as well as reduce the risk of development and improve the control of some chronic diseases

The relationship of vitamin D status with the development and course of diabetes mellitus type 1

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease that develops as a result of a genetic predisposition and environmental factors. Literature data indicate that the suboptimal status of vitamin D can be considered as a risk factor for the development of T1DM, especially at some stages of life. Adequate vitamin D supplementation in childhood may provide a protective effect and reduce the risk of developing T1DM at a later age. Pathogenesis of T1DM predisposes to abnormalities in the metabolism of vitamin D, including the development of vitamin D deficiency. Moreover, the immunomodulating effect of calcitriol (induction of immune tolerance and T-cell anergy, impaired B-cell activity and antibodies production) suggests the therapeutic potential of vitamin D in autoimmune diseases, including T1DM. A number of studies have demonstrated the positive clinical effects of various vitamin D preparations with respect to maintaining residual β-cell function, improving glycemia control in patients with T1DM. Determining the optimal doses of vitamin D for patients with T1DM may contribute to disease control and prevention of complications

The «cut-off point» of vitamin D: a method of suppressing excessive secretion of PTH

BACKGROUND: The subject of discussion is the issue of the separation point, which determines sufficient levels of vitamin D for bone health. When determining the adequate reference range of vitamin D, researchers are mainly guided by the results of research, where the level of 25(OH)D is determined, at which the PTH level decreases and reaches a plateau. AIM: To establish the «cut-off point» of vitamin D by suppressing excessive secretion of PTH. MATERIALS AND METHODS: Observational, single-site, single-stage, selective, uncontrolled study of the search for vitamin D levels by the effect on PTH secretion in residents of Tyumen region was conducted (n = 176). All selected study participants determined the level of 25(OH)D and PTH in serum. The calculation of the «cut-off point» was carried out using the method of searching for changes in the correlation dependence of PTH on the level of vitamin D, followed by verification of the data obtained using ROC analysis. RESULTS: A mathematical analysis of the dependence of 25(OH)D and PTH showed the “cut-off point” of vitamin D, equal to – 23.6 ng/ml. CONCLUSION: The “cut-off point” of 23.6 ng/ml is optimal for suppressing excessive PTH secretion. The data obtained may be an incentive for further working out the “cut-off point” of vitamin D for the Russian population and can be used to clarify the classification of deficiency, insufficiency and optimal levels of vitamin D for the population of the Russian Federation

National survey of doctors on hypo-and hypernatremia in the context of real clinical practice

BACKGROUND: The prevalence of dysnatremia varies widely (from 1 to 63%), and depends on comorbidities, the effects of more than 18 hormones and hormone-like substances, which confirms the importance of maintaining blood sodium levels in the tight physiologic range and makes it possible to consider its deviations as an endocrine pathology. Both hypo- and hypernatraemia are associated with a multiple increase in mortality, risk of fractures, and gross balance disturbances. At the same time, the clinical manifestations of dysnatremia are not specific, reflect an osmotically mediated decrease in brain function, which potentially may be missed in clinical practice. AIMS: to study the specifics of diagnosis, differential diagnosis and treatment of dysnatremia states by specialist doctors using a sociological survey method. MATERIALS AND METHODS: A cross-sectional sociological uncontrolled study was conducted by questioning doctors about hypo- and hypernatremia using the online questionnaire “Questionnaire on hypo-and hypernatremia in clinical practice” created on the Google forms platform. The invitation to fill in the questionnaire was sent to the email addresses included in the database of the Russian Association of Endocrinologists. A total of 353 completed questionnaires were received. RESULTS: The poll demonstrated a low frequency of determining blood sodium levels - less than 38% of specialists prescribe sodium in more than half of the cases, including the cases of diseases associated with dysnatremia, which correlates with less practical experience of doctors. The overwhelming majority of endocrinologists (82%) in their clinical practice encounters deviations of the sodium levels in patients, but only 6% recognize the possession of the competence of managing patients with dysnatremia. The discrepancy between the lower limit of normal range to 135-136 mmol/l was observed in 22% (62/278), the inconsistency of the upper normal limit to 145-146 mmol/l - in 47% (131/278) of laboratories, and in 33% (41/278) laboratories, which are used by doctors, there was a discrepancy along both limits of the reference interval. The presence of a hypertonic solution (3%) of sodium chloride in a hospital was noted only by 38% of respondents. Conclusions: There is an unphysiological variation in reference intervals for blood sodium concentration in 55% of laboratories, a low frequency of sodium levels evaluation in the blood (in more than half of clinical situations only 38.2% of doctors prescribe the estimation of blood sodium level) and the lack of educational competence in managing patients with syndromes of hypo- and hypernatremia in 94% of endocrinologists

Late consequences of classic congenital adrenal hyperplasia and its long-term poor control in men (case report and literature review)

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is an autosomal recessive disorder of the adrenal cortex characterized by impairment of cortisol biosynthesis (with possible impairment of aldosterone biosynthesis) and excessive pituitary ACTH release, which promotes oversecretion of intact pathways products: 17-hydroxyprogesterone (17OHP), progesterone, and adrenal androgens – androstendione and testosterone. 21-hydroxylase deficiency, being the most common cause of congenital adrenal hyperplasia is a chronic disorder, that requires life-long glucocorticoid treatment, that aims both to replace cortisol and prevent ACTH-driven androgen excess. Nevertheless, reaching the optimal glucocorticoid dose is challenging because currently available glucocorticoid formulations cannot replicate the physiological circadian rhythm of cortisol secretion. The difficulties in striking the balance between uneffective normalizing of ACTH-level and excess glucocorticoid exposure leads to different abnormalities, that starts to develop at first months of life and progress, frequently gaining especial clinical meaning in adult age. In the present clinical case we introduce 35 years old male patient with salt-wasting form of 21-hydroxylase deficiency, which had either complications considered to progress due to insufficient glucocorticoid therapy, and some metabolic abnormalities, associated with supraphysiological doses of glucocorticoids

Рис. 1. Генеалогические деревья, демонстрирующие 1 и 2 семью соответственно.

Currently, many AIP mutations responsible for the development of pituitary adenomas have been described. Penetence of pituitary adenomas in AIP-positive FIPA families is incomplete and varies widely. Data on the characteristics of metabolic changes in patients with familial pituitary adenomas associated with mutations in the AIP gene continues to be inadequate. Evaluation of the results of molecular genetic studies, as well as a thorough analysis of metabolic changes in these clinical cases, will help to develop and improve diagnostic and treatment algorithms, identify patient groups that require special attention of endocrinologists, timely screening, aggressive treatment, and careful dynamic observation

Difficulties in diagnosis of adenomas with mixed prolactin and growth hormone secretion: case presentation

Hyperpolactinemia is a persistent excess of prolactin in the blood serum. The symptom complex of hyperprolactinemia primarily consists of disturbances in function of the reproductive system. The secretion of prolactin is under complex neuroendocrine control, which involves factors of different nature: neurotransmitters, hormones of the peripheral endocrine glands. In most cases, prolactin is secreted by pituitary cells - lactotrophs, but in some cases, hypersecretion of prolactin is combined with an excess production of growth hormone, which is typical for tumors originating from the line of progenitor cells of lactotrophs and somatotrophs of the pituitary gland, mammosomatotrophs. In this case, the symptom complex of hyperprolactinemia is accompanied by clinical manifestations of acromegaly. In patients with acromegaly, the cause of hyperprolactinemia may be pituitary stalk compression or mixed secretion of prolactin and growth hormone. Differentiation of lactotropic and somatotropic pituitary cells is determined by transcription factor Pit-1. These cell lineages are closely connected,  and this may be one of the reasons for formation of tumors with mixed secretion. Reports of late presentation of acromegaly in patients previously diagnosed with prolactinomas have also been described in literature.Clinical manifestations of hyperprolactinemia can cause the patient to seek doctor’s attention before acromegalic changes in appearance develop. Careful attention is needed both to the primary diagnosis and to the clinical course of the disease in patients with hyperprolactinemia and pituitary adenoma: full assessment of hormonal status with mandatory evaluation of IGF-1 is crucial at initial examination, during further observation it may be advised to consider periodic evaluation of IGF-1 in addition to assessment of prolactin and the size of adenoma.  Pituitary adenomas with mixed secretion may have a poorer prognosis

Pegvisomant and current approaches to the medical treatment of acromegaly (literature review and case report)

This review provides the main results of clinical trials and the literature on the experience of using pegvisomant, the first drug from the class of growth hormone receptor antagonists. The mechanism of action of the drug, its effectiveness with respect to disease control and its effect on complications, information on adverse events, and brief information on the experience of use during pregnancy are discussed in detail. In conclusion, a clinical observation of successful use of pegvisomant in resistant to standart treatment acromegaly is given. A discussion of the available literature data, the results of clinical studies and practical experience allows us to conclude that the drug is highly effective in terms of achieving biochemical remission of acromegaly, and also has a number of additional valuable properties: it is capable of improvement of patients’ glucose metabolism and quality of life and has a minimal amount of adverse events. Pegvisomant is currently registered in the Russian Federation only for use in monotherapy; the possibility of combination therapy with somatostatin analogues will additionally allow to reliably control the growth of the pituitary adenoma and significantly cut treatment costs by reducing the dose of pegvisomant. These features of the drug make it very relevant when discussing issues related to drug therapy of acromegaly, and suggest a good prospect for use in clinical practice

The efficacy of high-dose cabergoline treatment of prolactinomas resistant to standard doses: a clinical observation

Hyperprolactinemia (HP) is one of the most common neuroendocrine disorders. In 60% of cases, pathological HP is caused by pituitary prolactin-secreting adenoma. Therapy with agonists of dopamine type 2 receptors (D2 receptor agonists) is a method of choice for the treatment of pathological HP which allows to achieve prolactin normalization and reduction of pituitary adenoma in most cases. However, 15-20% of patients are resistant to D2 receptor agonists, and the question of overcoming this resistance is highly relevant. Different approaches are considered to solve this problem, one - is to increase the dose of D2 receptor agonists up to the maximally tolerated. In this article, we present a clinical observation of a patient with a partial resistance to D2 receptor agonists who demonstrated a good response to treatment with high doses of cabergoline