Abnormal plasma sodium concentrations in patients treated with desmopressin for cranial diabetes insipidus: results of a long-term retrospective study

Arginine vasopressin deficiency: diagnosis, management and the relevance of oxytocin deficiency

Polyuria-polydipsia syndrome can be caused by central diabetes insipidus, nephrogenic diabetes insipidus or primary polydipsia. To avoid confusion with diabetes mellitus, the name 'central diabetes insipidus' was changed in 2022 to arginine vasopressin (AVP) deficiency and 'nephrogenic diabetes insipidus' was renamed as AVP resistance. To differentiate the three entities, various osmotic and non-osmotic copeptin-based stimulation tests have been introduced in the past decade. The hypertonic saline test plus plasma copeptin measurement emerged as the test with highest diagnostic accuracy, replacing the water deprivation test as the gold standard in differential diagnosis of the polyuria-polydipsia syndrome. The mainstay of treatment for AVP deficiency is AVP replacement with desmopressin, a synthetic analogue of AVP specific for AVP receptor 2 (AVPR2), which usually leads to rapid improvements in polyuria and polydipsia. The main adverse effect of desmopressin is dilutional hyponatraemia, which can be reduced by regularly performing the so-called desmopressin escape method. Evidence from the past few years suggests an additional oxytocin deficiency in patients with AVP deficiency. This potential deficiency should be further evaluated in future studies, including feasible provocation tests for clinical practice and interventional trials with oxytocin substitution.

Diabetes insipidus: Vasopressin deficiency…

Diabetes insipidus is a disorder characterized by hypo-osmotic polyuria secondary to abnormal synthesis, regulation, or renal action of antidiuretic hormone. Recently, an expert group, with the support of patient associations, proposed that diabetes insipidus be renamed to avoid confusion with diabetes mellitus. The most common form of diabetes insipidus is secondary to a dysfunction of the neurohypophysis (central diabetes insipidus) and would be therefore named 'vasopressin deficiency'. The rarer form, which is linked to renal vasopressin resistance (nephrogenic diabetes insipidus), would then be named 'vasopressin resistance'. The etiology of diabetes insipidus is sometimes clear, in the case of a neurohypophyseal cause (tumoral or infiltrative damage) or a renal origin, but in some cases diabetes insipidus can be difficult to distinguish from primary polydipsia, which is characterized by consumption of excessive quantities of water without any abnormality in regulation or action of antidiuretic hormone. Apart from patients' medical history, physical examination, and imaging of the hypothalamic-pituitary region, functional tests such as water deprivation or stimulation of copeptin by hyperosmolarity (induced by infusion of hypertonic saline) can be proposed in order to distinguish between these different etiologies. The treatment of diabetes insipidus depends on the underlying etiology, and in the case of a central etiology, is based on the administration of desmopressin which improves patient symptoms but does not always result in an optimal quality of life. The cause of this altered quality of life may be oxytocin deficiency, oxytocin being also secreted from the neurohypophysis, though this has not been fully established. The possibility of a new test using stimulation of oxytocin to identify alterations in oxytocin synthesis is of interest and would allow confirmation of a deficiency in those patients presenting with diabetes insipidus linked to neurohypophyseal dysfunction.

When Thirst Ceases to Exist: A Case Report and Literature Review of Adipsic Diabetes Insipidus Following Coil Embolization of a Ruptured Anterior Communicating Artery Aneurysm

Diabetes insipidus is a condition characterized by inappropriately dilute urine in the setting of serum hyperosmolality. The two predominant subtypes include central (from lack of vasopressin production) and nephrogenic diabetes insipidus (from renal resistance to circulating vasopressin). A common manifestation is the significant pursuant thirst from excessive polyuria. We present a case report and literature review of an infrequent variation of central diabetes insipidus known as adipsic (hypothalamic) diabetes insipidus, characterized by the absence of thirst, secondary to coiling of a ruptured anterior communicating artery aneurysm. Due to the loss of thirst, patients are at a heightened risk for hypernatremia and complications secondary to dehydration. Our patient's course was complicated by recurrent polyuria and hypernatremia, requiring a fixed-dose desmopressin regimen. On follow-up, only partial thirst sensation was restored. We provide a literature review to compare our case report to the scant literature available to broaden the awareness of this infrequent, perilous, manifestation.

Position statement on the diagnosis and management of congenital pituitary deficiency in adults: The French National Diagnosis and Treatment Protocol (NDTP)

Pituitary deficiency, or hypopituitarism, is a rare chronic disease. It is defined by insufficient synthesis of one or more pituitary hormones (growth hormone, TSH, ACTH, LH-FSH, prolactin), whether or not associated with arginine vasopressin deficiency (formerly known as diabetes insipidus). In adult patients, it is usually acquired (notably during childhood), but can also be congenital, due to abnormal pituitary development. The present study focuses on congenital pituitary deficiency in adults, from diagnosis to follow-up, including special situations such as pregnancy or the elderly. The clinical presentation is highly variable, ranging from isolated deficit to multiple deficits, which may be part of a syndromic form or not. Diagnosis is based on a combination of clinical, biological (assessment of all hormonal axes), radiological (brain and hypothalamic-pituitary MRI) and genetic factors. Treatment consists in hormonal replacement therapy, adapted according to the period of life and the deficits, which may be progressive. Comorbidities, risk of complications and acute decompensation, and the impact on fertility and quality of life all require adaptative multidisciplinary care and long-term monitoring.

New insights on diagnosis and treatment of AVP deficiency

Arginine vasopressin deficiency (AVP-D) is one of the main entities of the polyuria-polydipsia syndrome. Its correct diagnosis and differentiation from the other two causes - AVP resistance and primary polydipsia - is crucial as this determines the further management of these patients.Over the last years, several new diagnostic tests using copeptin, the stable surrogate marker of AVP, have been introduced. Among them, hypertonic saline stimulated copeptin was confirmed to reliably and safely improve the diagnostic accuracy to diagnose AVP-D. Due to its simplicity, arginine stimulated copeptin was put forward as alternative test procedure. Glucagon-stimulated copeptin also showed promising results, while the oral growth hormone secretagogue Macimorelin failed to provide a sufficient stimulus. Interestingly, an approach using machine learning techniques also showed promising results concerning diagnostic accuracy.Once AVP-D is diagnosed, further workup is needed to evaluate its etiology. This will partly define the further treatment and management. In general, treatment of AVP-D focuses on desmopressin substitution, with oral formulations currently showing the best tolerance and safety profile. However, in addition to desmopressin substitution, recent data also showed that psychopathological factors play an important role in managing AVP-D patients.

Desmopressin Dose Requirements in Adults with Congenital and Acquired Central Diabetes Insipidus

Central diabetes insipidus is a rare disorder characterized by a deficiency of vasopressin. The first line drug to treat this disorder is a synthetic analogue of vasopressin, desmopressin.The primary aim of this retrospective register study was to compare desmopressin dose requirements in patients with acquired and congenital DI, and secondly to assess the influence of BMI on dose requirement and risk of hyponatremia with different drug administrations. We included all patients with suspected DI attending the endocrine department at Rigshospitalet, Copenhagen, Denmark in 2022. We identified 222 patients who were included whereof 130/222 (58.6%) were females and median age was 53 years (IQR 35 to 63). The etiology included 7/222 (3.2%) congenital and 215/222 (96.8%) acquired. After converting nasal and sublingual doses to equivalent oral doses, the median daily dose requirement was 600 μg in patients with congenital etiology compared to 200 μg in patients with acquired etiology (p=0.005). We found no association between BMI and desmopressin dose requirements (p=0.6). During the past 12 months, 66/215 (30.7%) had sodium levels<136 mmol/l including 20/215 (9.3%) with sodium levels<131 mmol/l. No increased risk of hyponatremia was found, when nasal and oral were compared (p=0.9). Daily desmopressin dose requirements were higher in patients with congenital DI compared to patients with acquired DI. However, this result was associated with uncertainty due to the small congenital group. BMI did not influence daily dose requirements and nor did type of administration influence the risk of hyponatremia.

Clinical Characteristics of Adipsic Diabetes Insipidus

OBJECTIVE

Adipsic diabetes insipidus (ADI) is a life-threatening disease. It is characterized by arginine vasopressin deficiency and thirst absence. Data about clinical characteristics of ADI were scarce. This study investigated the clinical features of hospitalized ADI patients.

METHODS

A retrospective study was conducted of hospitalized ADI patients admitted to the Endocrinology Department of Huashan Hospital between January 2014 and December 2021, and compared with central diabetes insipidus (CDI) patients with normal thirst.

RESULTS

During the study period, there were a total of 507 hospitalized CDI patients, among which 50 cases were ADI, accounting for 9.9%. Forty percent of ADI patients were admitted due to hypernatremia, but there were no admissions due to hypernatremia in the control group. The lesions of ADI patients were more likely to be located in the suprasellar area (100% vs 66%, P < .05). Higher prevalence of hypothalamic dysfunction (76% vs 8%, P < .001), central hypothyroidism (100% vs 90%, P = .031), hyperglycemia (66% vs 32%, P < .001), dyslipidemia (92% vs 71%, P = .006), and hyperuricemia (64% vs 37%, P = .003) was found in the ADI group than in the control group. The proportions of hypernatremia were higher in the ADI group both at admission and at discharge (90% vs 8%, 68% vs 8%, respectively, both with P < .001), contributing to higher prevalence of complications, such as renal insufficiency, venous thrombosis, and infection.

CONCLUSION

ADI patients were found with higher prevalence of hypernatremia, hypopituitarism, hypothalamic dysfunction, metabolic disorders, and complications, posing a great challenge for comprehensive management.

Pediatric endocrinopathies related to COVID-19: an update

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the seventh coronavirus to be linked to human disease. The SARS-CoV-2 virus may have several pathophysiologic interactions with endocrine systems, resulting in disruptions in glucose metabolism, hypothalamus and pituitary function, adrenal function, and mineral metabolism. An increasing amount of evidence demonstrates both the influence of underlying endocrine abnormalities on the outcome of COVID-19 and the effect of the SARS-CoV-2 virus on endocrine systems. However, a systematic examination of the link to pediatric endocrine diseases has been missing.

DATA SOURCES

The purpose of this review is to discuss the impact of SARS-CoV-2 infection on endocrine systems and to summarize the available knowledge on COVID-19 consequences in children with underlying endocrine abnormalities. For this purpose, a literature search was conducted in EMBASE, and data that were discussed about the effects of COVID-19 on endocrine systems were used in the current study.

RESULTS

Treatment suggestions were provided for endocrinopathies associated with SARS-CoV-2 infection.

CONCLUSIONS

With the global outbreak of COVID-19, it is critical for pediatric endocrinologists to understand how SARS-CoV-2 interacts with the endocrine system and the therapeutic concerns for children with underlying problems who develop COVID-19. While children and adults share certain risk factors for SARS-CoV-2 infection sequelae, it is becoming obvious that pediatric responses are different and that adult study results cannot be generalized. While pediatric research gives some insight, it also shows the need for more study in this area.

Pituitary and SARS CoV-2: An unremitting conundrum

There is increased interest related to the impact of coronavirus disease 19 (COVID-19) on the endocrine system and in particular on the pituitary gland. Over the course of the severe infection with acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there are both acute and delayed effects on the pituitary, related to infection and/or treatment. Hypopituitarism, pituitary apoplexy and hypophysitis have been all reported, as well as arginine vasopressin deficiency (diabetes insipidus) and syndrome of inappropriate antidiuretic hormone secretion. Furthermore, patients with acromegaly, Cushing's disease and hypopituitarism are theoretically at increased risk of complications with COVID-19 and require close monitoring. Evidence regarding pituitary dysfunction in patients with COVID-19 continues to be gathered, as the breadth and depth of knowledge also continues to rapidly evolve. This review summarizes data analysis to date on the possible effects of COVID-19 and COVID-19 vaccination on patients with normal pituitary function and patients with known pituitary pathology. Though clinical systems were significantly affected, it seems there is no overall loss of biochemical control in patients with certain pituitary pathologies.

Correlation of Pituitary Descent and Diabetes Insipidus After Transsphenoidal Pituitary Macroadenoma Resection

BACKGROUND

Endoscopic transsphenoidal surgery remains the technique of choice for resection of pituitary adenoma. Postoperative diabetes insipidus (DI) is most often transient and observed in 1.6% to 34% of patients, whereas permanent DI has been reported in 0% to 2.7% of patients. The proposed mechanism was the transduction of traction forces exerted by the surgeon on the descended diaphragma sellae and through the pituitary stalk.

OBJECTIVE

To quantify and correlate the degree of pituitary gland descent with postoperative DI.

METHODS

Of 374 patients who underwent transsphenoidal resection of a pituitary adenoma between 2010 and 2020 at our institution, we report a cohort of 30 patients (Group A) DI. We also report a matched cohort by tumor volume of 30 patients who did not develop DI (Group B). We quantified the tension on the pituitary stalk by calculating pituitary descent interval (PDI) by comparing preoperative and postoperative position of the pituitary gland and using Pythagoras' formula where , with craniocaudal (CC) and anterior-posterior (AP) representing measurements of pituitary translation in respective directions after resection.

RESULTS

Patients who developed DI had significantly greater pituitary gland translations in the craniocaudal (23.0 vs 16.3 mm, P = .0015) and anteroposterior (2.4 vs 1.5 mm, P = .0168) directions. Furthermore, Group A had a statistically greater PDI, which was associated with development of DI (23.2 vs 16.6 mm, P = .0017).

CONCLUSION

We were able to quantify pituitary descent and subsequent tension on the pituitary stalk, while also associating it with development of postoperative DI after pituitary adenoma resection.

New developments and concepts in the diagnosis and management of diabetes insipidus (AVP-deficiency and resistance)

Diabetes insipidus (DI) is a disorder characterised by the excretion of large amounts of hypotonic urine, with a prevalence of 1 per 25,000 population. Central DI (CDI), better now referred to as arginine vasopressin (AVP)-deficiency, is the most common form of DI resulting from deficiency of the hormone AVP from the pituitary. The less common nephrogenic DI (NDI) or AVP-resistance develops secondary to AVP resistance in the kidneys. The majority of causes of DI are acquired, with CDI developing when more than 80% of AVP-secreting neurons are damaged. Inherited/familial CDI causes account for approximately 1% of cases. Although the pathogenesis of NDI is unclear, more than 280 disease-causing mutations affecting the AVP2 protein or AVP V2 receptor, as well as in aquaporin 2 (AQP2), have been described. Although the cAMP/protein kinase A pathway remains the major regulatory pathway of AVP/AQP2 action, in vitro data have also revealed additional cAMP independent pathways of NDI pathogenesis. Diagnosing partial forms of DI, and distinguishing them from primary polydipsia, can be challenging, previously necessitating the use of the water deprivation test. However, measurements of circulating copeptin levels, especially after stimulation, are increasingly replacing the classical tests in clinical practice because of their ease of use and high sensitivity and specificity. The treatment of CDI relies on desmopressin administration, whereas NDI requires the management of any underlying diseases, removal of offending drugs and, in some cases, administration of diuretics. A better understanding of the pathophysiology of DI has led to novel evolving therapeutic agents that are under clinical trial.

Treating Hypopituitarism in the Over 65s: Review of Clinical Studies

The current increase of life expectancy is associated with the presence of endocrine diseases in the elderly. The management of hypopituitarism in this group of patients is a challenging task. A correct diagnosis, which represents an essential requisite for an appropriate medical treatment, can be difficult because of the physiological changes occurring in pituitary function with aging, which may lead to challenges in the interpretation of laboratory results. Furthermore, the treatment requires several careful considerations: the need to restore the hormonal physiology with replacement therapies must be balanced with the need to avoid the risks of the over-replacement, especially in the presence of concomitant cardiovascular and metabolic disease. Interactions with other drugs able to modify the absorption and/or the metabolism of hormonal replacement therapies should be considered, in particular for the treatment of hypoadrenalism and hypothyroidism. The most important challenges stem from the lack of specific studies focused on the management of hypopituitarism in older people.

Central diabetes insipidus from a patient's perspective: management, psychological co-morbidities, and renaming of the condition: results from an international web-based survey

BACKGROUND

Central diabetes insipidus is a rare neuroendocrine condition. Data on treatment-associated side-effects, psychological comorbidities, and incorrect management are scarce. The aim of this study was to investigate patients' perspectives on their disease.

METHODS

This study used a cross-sectional, web-based, anonymous survey, developed by endocrinologists and patient representatives, to collect the opinions of patients with central diabetes insipidus on management and complications of their disease, psychological comorbidities, degree of knowledge and awareness of the condition among health-care professionals, and renaming the disease to avoid confusion with diabetes mellitus (diabetes).

FINDINGS

Between Aug 23, 2021, and Feb 7, 2022, 1034 patients with central diabetes insipidus participated in the survey. 91 (9%) participants were children and adolescents (37 [41%] girls and 54 [59%] boys; median age 10 years [IQR 6-15]) and 943 (91%) were adults (757 [80%] women and 186 [20%] men]; median age 44 years [34-54]). 488 (47%) participants had isolated posterior pituitary dysfunction and 546 (53%) had combined anterior and posterior pituitary dysfunction. Main aetiologies were idiopathic (315 [30%] of 1034 participants) and tumours and cysts (pre-surgical 217 [21%]; post-surgical 254 [25%]). 260 (26%; 95% CI [0·23-0·29]) of 994 patients on desmopressin therapy had hyponatraemia leading to hospitalisation. Patients who routinely omitted or delayed desmopressin to allow intermittent aquaresis had a significantly lower prevalence of hyponatraemia compared with those not aware of this approach (odds ratio 0·55 [95% CI 0·39-0·77]; p=0·0006). Of patients who had to be hospitalised for any medical reason, 71 (13%; 95% CI 0·10-0·16) of 535 patients did not receive desmopressin while in a fasting state (nil by mouth) without intravenous fluid replacement and reported symptoms of dehydration. 660 (64%; 0·61-0·67) participants reported lower quality of life, and 369 (36%; 0·33-0·39) had psychological changes subjectively associated with their central diabetes insipidus. 823 (80%; 0·77-0·82) participants encountered a situation where central diabetes insipidus was confused with diabetes mellitus (diabetes) by health-care professionals. 884 (85%; 0·83-0·88) participants supported renaming the disease; the most favoured alternative names were vasopressin deficiency and arginine vasopressin deficiency.

INTERPRETATION

This is the largest survey of patients with central diabetes insipidus, reporting a high prevalence of treatment-associated side-effects, mismanagement during hospitalisation, psychological comorbidities, and a clear support for renaming the disease. Our data are the first to indicate the value of routinely omitting or delaying desmopressin.

FUNDING

Swiss National Science Foundation, Swiss Academy of Medical Sciences, and G&J Bangerter-Rhyner-Foundation.

Diagnosis and Management of Central Diabetes Insipidus in Adults

Central diabetes insipidus (CDI) is a clinical syndrome which results from loss or impaired function of vasopressinergic neurons in the hypothalamus/posterior pituitary, resulting in impaired synthesis and/or secretion of arginine vasopressin (AVP). AVP deficiency leads to the inability to concentrate urine and excessive renal water losses, resulting in a clinical syndrome of hypotonic polyuria with compensatory thirst. CDI is caused by diverse etiologies, although it typically develops due to neoplastic, traumatic, or autoimmune destruction of AVP-synthesizing/secreting neurons. This review focuses on the diagnosis and management of CDI, providing insights into the physiological disturbances underpinning the syndrome. Recent developments in diagnostic techniques, particularly the development of the copeptin assay, have improved accuracy and acceptability of the diagnostic approach to the hypotonic polyuria syndrome. We discuss the management of CDI with particular emphasis on management of fluid intake and pharmacological replacement of AVP. Specific clinical syndromes such as adipsic diabetes insipidus and diabetes insipidus in pregnancy as well as management of the perioperative patient with diabetes insipidus are also discussed.

Copeptin in fluid disorders and stress

Copeptin, a glycosylated peptide of 39 amino acids, is the C-terminal segment of arginine vasopressin (AVP) precursor peptide, which is consisted of two other fragments, vasopressin and neurophysin Ⅱ. The main physiological functions of AVP are fluid and osmotic balance, cardiovascular homeostasis and regulation of the endocrine stress response. Numerous studies have demonstrated that the endogenous AVP in plasma is a meaningful biomarker to guide diagnosis and therapy of diseases associated with fluids disorders and stress. However, due to its instability, short half-time life in circulation and lack of readily available AVP assays, clinical measurement of AVP is restricted. In contrast to AVP, copeptin which is released in an equimolar mode with AVP from the pituitary, has emerged as a stable and simple-to-measure surrogate marker of AVP and displays excellent potential in diagnosis, differentiation and prognosis of various diseases. This review will discuss the studies on the clinical value of copeptin in different diseases, especially in AVP-dependent fluids disorders, as well as issues and prospects of the application of this potential biomarker.

Diabetes insipidus

Diabetes insipidus (DI) is a disorder characterized by a high hypotonic urinary output of more than 50ml per kg body weight per 24 hours, with associated polydipsia of more than 3 liters a day [1,2]. Central DI results from inadequate secretion and usually deficient synthesis of Arginine vasopressin (AVP) in the hypothalamus or pituitary gland. Besides central DI further underlying etiologies of DI can be due to other primary forms (renal origin) or secondary forms of polyuria (resulting from primary polydipsia). All these forms belong to the Polyuria Polydipsia Syndrom (PPS). In most cases central and nephrogenic DI are acquired, but there are also congenital forms caused by genetic mutations of the AVP gene (central DI) [3] or by mutations in the gene for the AVP V2R or the AQP2 water channel (nephrogenic DI) [4]. Primary polydipsia (PP) as secondary form of polyuria includes an excessive intake of large amounts of fluid leading to polyuria in the presence of intact AVP secretion and appropriate antidiuretic renal response. Differentiation between the three mentioned entities is difficult [5], especially in patients with Primary polydipsia or partial, mild forms of DI [1,6], but different tests for differential diagnosis, most recently based on measurement of copeptin, and a thorough medical history mostly lead to the correct diagnosis. This is important since treatment strategies vary and application of the wrong treatment can be dangerous [7]. Treatment of central DI consists of fluid management and drug therapy with the synthetic AVP analogue Desmopressin (DDAVP), that is used as nasal or oral preparation in most cases. Main side effect can be dilutional hyponatremia [8]. In this review we will focus on central diabetes insipidus and describe the prevalence, the clinical manifestations, the etiology as well as the differential diagnosis and management of central diabetes insipidus in the out- and inpatient setting.

Management of a patient with Sheehan's syndrome and diabetes insipidus complicated by recurrent hyponatremia

SUMMARY

A 38-year-old female was initially seen in the intensive care unit after severe postpartum hemorrhage. She was initially diagnosed to have Sheehan's syndrome and after discharge, she was diagnosed to have a vesicovaginal fistula which initially caused a delay in diagnosing diabetes insipidus in the patient because she was having urinary incontinence. The patient had the vesicovaginal fistula repaired and was on replacement with levothyroxine, prednisone, and desmopressin. Years after her diagnosis, the patient experienced recurrent episodes of hyponatremia in the setting of desmopressin therapy. This case highlights the challenges of diagnosing diabetes insipidus in a patient with Sheehan's syndrome and a vesicovaginal fistula, as well as the long-term management of central diabetes insipidus in a resource-limited setting.

LEARNING POINTS

Sheehan's syndrome is rarely associated with diabetes insipidus, and in our patient, it was initially missed due to a vesicovaginal fistula which caused urinary incontinence. Water intoxication is more common in young children and older adults but can occur years after initiating treatment with desmopressin in adults and should be kept in mind when treating patients with hyponatremia who have hypopituitarism associated with diabetes insipidus. Water intoxication is much more common in patients with diabetes insipidus being treated with intranasal desmopressin than in those using the oral preparations.

Effects of desmopressin acetate administration in healthy dogs receiving prednisolone

Background

Glucocorticoids are used for a variety of purposes in veterinary medicine but often are associated with clinically important adverse effects. Polyuria and polydipsia are the most frustrating adverse effects noted by owners.

Objective

To determine whether administration of desmopressin ameliorates polyuria and polydipsia associated with prednisolone administration.

Animals

Seven healthy adult Walker Hounds.

Methods

Prospective hypothesis testing study. Daily water intake and urine specific gravity (USG) were measured in dogs under 4 separate sequential conditions: no medications (C), prednisolone only (P), prednisolone and desmopressin (PD), and prednisolone after discontinuation of desmopressin (PAD).

Results

When compared to baseline, 6 of 7 dogs became polydipsic after administration of prednisolone (0.5 mg/kg PO q12h). When desmopressin (5 μg/dog SC q12h) was administered to dogs receiving prednisolone, significant decreases in water intake and serum sodium concentration occurred, and USG increased significantly.

Conclusions and Clinical Importance

Administration of desmopressin to dogs receiving prednisolone significantly decreased water intake and serum sodium concentration, and increased USG. Our results suggest that, in some dogs, desmopressin ameliorates the most important adverse effect of prednisolone noted by owners, but that hyponatremia is an important complication associated with desmopressin use.

ENDOCRINOLOGY IN THE TIME OF COVID-19-2021 UPDATES: The management of diabetes insipidus and hyponatraemia

COVID-19 has changed the nature of medical consultations, emphasizing virtual patient counselling, with relevance for patients with diabetes insipidus (DI) or hyponatraemia. The main complication of desmopressin treatment in DI is dilutional hyponatraemia. Since plasma sodium monitoring is not always possible in times of COVID-19, we recommend to delay the desmopressin dose once a week until aquaresis occurs allowing excess retained water to be excreted. Patients should measure their body weight daily. Patients with DI admitted to the hospital with COVID-19 have a high risk for mortality due to volume depletion. Specialists must supervise fluid replacement and dosing of desmopressin. Patients after pituitary surgery should drink to thirst and measure their body weight daily to early recognize the development of postoperative SIAD. They should know hyponatraemia symptoms. Hyponatraemia in COVID-19 is common with a prevalence of 20-30% and is mostly due to SIAD or hypovolaemia. It mirrors disease severity and is an early predictor of mortality. Hypernatraemia may also develop in COVID-19 patients, with a prevalence of 3-5%, especially in ICU, and derives from different multifactorial reasons, for example, due to insensible water losses from pyrexia, increased respiration rate and use of diuretics. Hypernatraemic dehydration may contribute to the high risk of acute kidney injury in COVID-19. IV fluid replacement should be administered with caution in severe cases of COVID-19 because of the risk of pulmonary oedema.

Diagnosis and management of diabetes insipidus for the internist: an update

Diabetes insipidus is a disorder characterized by excretion of large amounts of hypotonic urine. Four entities have to be differentiated: central diabetes insipidus resulting from a deficiency of the hormone arginine vasopressin (AVP) in the pituitary gland or the hypothalamus, nephrogenic diabetes insipidus resulting from resistance to AVP in the kidneys, gestational diabetes insipidus resulting from an increase in placental vasopressinase and finally primary polydipsia, which involves excessive intake of large amounts of water despite normal AVP secretion and action. Distinguishing between the different types of diabetes insipidus can be challenging. A detailed medical history, physical examination and imaging studies are needed to detect the aetiology of diabetes insipidus. Differentiation between the various forms of hypotonic polyuria is then done by the classical water deprivation test or the more recently developed hypertonic saline or arginine stimulation together with copeptin (or AVP) measurement. In patients with idiopathic central DI, a close follow-up is needed since central DI can be the first sign of an underlying pathology. Treatment of diabetes insipidus or primary polydipsia depends on the underlying aetiology and differs in central diabetes insipidus, nephrogenic diabetes insipidus and primary polydipsia. This review will discuss issues and newest developments in diagnosis, differential diagnosis and treatment, with a focus on central diabetes insipidus.

SARS-CoV-2 infection and paediatric endocrine disorders: Risks and management considerations

Background

Coronavirus-19 (COVID-19) is a disease caused by the SARS-CoV-2 virus, the seventh coronavirus identified as causing disease in humans. The SARS-CoV-2 virus has multiple potential pathophysiologic interconnections with endocrine systems, potentially causing disturbances in glucose metabolism, hypothalamic and pituitary function, adrenal function and mineral metabolism. A growing body of data is revealing both the effects of underlying endocrine disorders on COVID-19 disease outcome and the effects of the SARS-CoV-2 virus on endocrine systems. However, comprehensive assessment of the relationship to endocrine disorders in children has been lacking.

Content

In this review, we present the effects of SARS-CoV-2 infection on endocrine systems and review the current literature on complications of COVID-19 disease in underlying paediatric endocrine disorders. We provide recommendations on management of endocrinopathies related to SARS-CoV-2 infection in this population.

Summary and outlook

With the surge in COVID-19 cases worldwide, it is important for paediatric endocrinologists to be aware of the interaction of SARS-CoV-2 with the endocrine system and management considerations for patients with underlying disorders who develop COVID-19 disease. While children and adults share some risk factors that influence risk of complications in SARS-CoV-2 infection, it is becoming clear that responses in the paediatric population are distinct and outcomes from adult studies cannot be extrapolated. Evidence emerging from paediatric studies provides some guidance but highlights the need for more research in this area.

Adipsic diabetes insipidus

Adipsic diabetes insipidus (ADI) is a rare but devastating disorder of water balance with significant associated morbidity and mortality. Most patients develop the disease as a result of hypothalamic destruction from a variety of underlying etiologies. Damage to osmolar-responsive neuroreceptors, primarily within the supraoptic and paraventricular nuclei, results in impaired production and release of arginine vasopressin (AVP). Important regulating circuits of thirst sense and drive are regionally colocalized with AVP centers and therefore are also injured. Patients with central diabetes insipidus with impaired thirst response, defined as ADI, suffer from wide swings of plasma osmolality resulting in repeated hospitalization, numerous associated comorbidities, and significant mortality. Treatment recommendations are based largely on expert advice from case series owing to the rarity of disease prevalence. Acute disease management focuses on fixed dosing of antidiuretic hormone analogues and calculated prescriptions of obligate daily water intake. Long-term care requires patient/family education, frequent reassessment of clinical and biochemical parameters, as well as screening and treatment of comorbidities.

ADIPSIC DIABETES INSIPIDUS AFTER SECOND RESECTION OF A HYPOTHAMIC ASTROCYTOMA

OBJECTIVE

We report a case of adipsic diabetes insipidus (ADI) post-astrocytoma resection.

METHODS

Clinical and laboratory data are presented.

RESULTS

A 16-year-old female with a history of incompletely resected hypothalamic astrocytoma was admitted with a headache. Head magnetic resonance imaging showed an interval increase in a suprasellar lesion with extension to the third ventricle. Following a second stage resection, she developed an increased urine output with diluted urine resulting in a negative fluid balance; however, she was unable to sense thirst. Blood tests showed a serum sodium of 155 mEq/dL (normal, 136 to 145 mEq/dL), serum osmolality at 321 mOs/kg (normal, 285 to 295 mOs/kg) and a urine osmolality of 128 mOsm/kg (normal, 300 to 1,600 mOsm/kg). Serum creatinine and potassium were normal. Pituitary hormone profiles were found to be normal: growth hormone 0.171 ng/mL (normal, 0.123 to 8.05 ng/mL), luteinizing hormone 3.44 mIU/mL (normal, 7.59 to 89.08 mIU/mL), follicle-stimulating hormone 5.60 mIU/mL (normal, 2.55 to 16.69 mIU/mL), thyroid-stimulating hormone 2.9 mIU/mL (normal, 0.35 to 4.94 mIU/mL), free thyroxine 0.92 ng/dL (normal, 0.7 to 1.48 ng/dL), adrenocorticotropic hormone 19.56 pg/mL (normal, 7.2 to 63.3 pg/mL), and prolactin 7.25 ng/mL (normal, 5.18 to 26.53 ng/mL). The patient was treated with desmopressin acetate 120 μg tablets twice daily with a fixed fluid intake of 1.5 to 2.0 L/day with close monitoring of fluid intake, output, and body weight. The response was good with a gradual reduction of serum sodium level of around 7 to 9 mEq/L/day.

CONCLUSION

ADI is a rare entity of central diabetes insipidus, where the absence of polydipsia can be challenging in diagnosing and managing the condition. Cases of ADI are likely under reported and clinicians need to be aware of this condition.

Management of central diabetes insipidus

The treatment of central diabetes insipidus has not changed significantly in recent decades, and dDAVP and replacement of free water deficit remain the cornerstones of treatment. Oral dDAVP has replaced nasal dDAVP as a more reliable mode of treatment for chronic central diabetes insipidus. Hyponatraemia is a common side effect, occurring in one in four patients, and should be avoided by allowing a regular break from dDAVP to allow a resultant aquaresis. Hypernatraemia is less common, and typically occurs during hospitalization, when access to water is restricted, and in cases of adipsic DI. Management of adipsic DI can be challenging, and requires initial inpatient assessment to establish dose of dDAVP, daily fluid prescription, and eunatraemic weight which can guide day-to-day fluid targets in the long-term.

ENDOCRINOLOGY IN THE TIME OF COVID-19: Management of diabetes insipidus and hyponatraemia

COVID-19 has changed the nature of medical consultations, emphasizing virtual patient counseling, with relevance for patients with diabetes insipidus (DI) or hyponatraemia. The main complication of desmopressin treatment in DI is dilutional hyponatraemia. Since plasma sodium monitoring is not always possible in times of COVID-19, we recommend to delay the desmopressin dose once a week until aquaresis occurs allowing excess retained water to be excreted. Patients should measure their body weight daily. Patients with DI admitted to the hospital with COVID-19 have a high risk for mortality due to volume depletion. Specialists must supervise fluid replacement and dosing of desmopressin. Patients after pituitary surgery should drink to thirst and measure their body weight daily to early recognize the development of the postoperative syndrome of inappropriate antidiuresis (SIAD). They should know hyponatraemia symptoms. The prevalence of hyponatraemia in patients with pneumonia due to COVID-19 is not yet known, but seems to be low. In contrast, hypernatraemia may develop in COVID-19 patients in ICU, from different multifactorial reasons, for example, due to insensible water losses from pyrexia, increased respiration rate and use of diuretics. Hypernatraemic dehydration may contribute to the high risk of acute kidney injury in COVID-19. IV fluid replacement should be administered with caution in severe cases of COVID-19 because of the risk of pulmonary oedema.

Management of Hypopituitarism

Hypopituitarism includes all clinical conditions that result in partial or complete failure of the anterior and posterior lobe of the pituitary gland’s ability to secrete hormones. The aim of management is usually to replace the target-hormone of hypothalamo-pituitary-endocrine gland axis with the exceptions of secondary hypogonadism when fertility is required, and growth hormone deficiency (GHD), and to safely minimise both symptoms and clinical signs. Adrenocorticotropic hormone deficiency replacement is best performed with the immediate-release oral glucocorticoid hydrocortisone (HC) in 2–3 divided doses. However, novel once-daily modified-release HC targets a more physiological exposure of glucocorticoids. GHD is treated currently with daily subcutaneous GH, but current research is focusing on the development of once-weekly administration of recombinant GH. Hypogonadism is targeted with testosterone replacement in men and on estrogen replacement therapy in women; when fertility is wanted, replacement targets secondary or tertiary levels of hormonal settings. Thyroid-stimulating hormone replacement therapy follows the rules of primary thyroid gland failure with L-thyroxine replacement. Central diabetes insipidus is nowadays replaced by desmopressin. Certain clinical scenarios may have to be promptly managed to avoid short-term or long-term sequelae such as pregnancy in patients with hypopituitarism, pituitary apoplexy, adrenal crisis, and pituitary metastases.

Diabetes insipidus

Diabetes insipidus (DI) is a disorder characterized by excretion of large amounts of hypotonic urine. Central DI results from a deficiency of the hormone arginine vasopressin (AVP) in the pituitary gland or the hypothalamus, whereas nephrogenic DI results from resistance to AVP in the kidneys. Central and nephrogenic DI are usually acquired, but genetic causes must be evaluated, especially if symptoms occur in early childhood. Central or nephrogenic DI must be differentiated from primary polydipsia, which involves excessive intake of large amounts of water despite normal AVP secretion and action. Primary polydipsia is most common in psychiatric patients and health enthusiasts but the polydipsia in a small subgroup of patients seems to be due to an abnormally low thirst threshold, a condition termed dipsogenic DI. Distinguishing between the different types of DI can be challenging and is done either by a water deprivation test or by hypertonic saline stimulation together with copeptin (or AVP) measurement. Furthermore, a detailed medical history, physical examination and imaging studies are needed to ensure an accurate DI diagnosis. Treatment of DI or primary polydipsia depends on the underlying aetiology and differs in central DI, nephrogenic DI and primary polydipsia.

Management of hypothalamic disease in patients with craniopharyngioma

Patients with craniopharyngioma experience excess morbidity and mortality when compared with the background population and with other hypopituitary patients. Large, suprasellar tumours which form micropapillae into surrounding structures can cause hypothalamic damage before any therapeutic intervention; attempted gross total resection can lead to hypothalamic obesity, sleep disorders, thirst disorders and dysregulation of temperature as well as panhypopituitarism. The management of tumour bulk and the pathophysiology of hypothalamic complications have been reviewed extensively. We present a practical, clinical approach to management of hypothalamic disease in a patient with craniopharyngioma and highlight potential targets for future pharmacological or surgical intervention.

Adipsic diabetes insipidus secondary to craniopharyngioma resection

Adipsic diabetes insipidus is an infrequent disease which may be associated with craniopharyngioma. It may be secondary to the tumour's extension, as well as to resection of the mass. We present the case of a 24-year-old woman with a history of delayed puberty and hypothyroidism, but no prior study reports. She consulted due to a headache with warning signs associated with altered visual acuity. Brain MRI was performed which showed signs of a non-adenomatous lesion with suprasellar and hypothalamic extension. Following transcranial surgery, she developed diabetes insipidus criteria, with absence of thirst documented during the hospitalisation. The histopathological findings confirmed the diagnosis of craniopharyngioma. The patient was treated with desmopressin and received recommendations regarding rehydration according to the quantification of losses, with electrolyte stabilisation.

Diagnosis and management of central diabetes insipidus in adults

Central diabetes insipidus (CDI) is characterized by hypotonic polyuria due to impairment of AVP secretion from the posterior pituitary. In clinical practice, it needs to be distinguished from renal resistance to the antidiuretic effects of AVP (nephrogenic DI), and abnormalities of thirst appreciation (primary polydipsia). As nephrogenic diabetes insipidus is rare in adults, unless they are treated with lithium salts, the practical challenge is how to differentiate between CDI and clinical disorders of excess thirst. The differential diagnosis is usually straight forward, but the recommended gold standard test, the water deprivation test, is not without interpretative pitfalls. The addition of the measurement of plasma AVP concentrations improves diagnostic accuracy, but the radioimmunoassay for AVP is technically difficult, and is only available in a few specialized centres. More recently, the measurement of plasma copeptin concentrations has been claimed to provide a reliable alternative to measurement of plasma AVP, without the sampling handling challenges. In addition, the measurement of thirst ratings can help the differentiation between CDI and primary polydipsia. Once the diagnosis of CDI is biochemically certain, investigations to determine the cause of AVP deficiency are needed. In this review, we will outline the diagnostic approach to polyuria, revisit the caveats of the water deprivation test and review recent data on value of adding AVP/copeptin measurement. We will also discuss treatment strategies for CDI, with analysis of potential complications of treatment.

Desmopressin-Induced Severe Hyponatremia with Central Pontine Myelinolysis: A Case Report

Desmopressin, a synthetic vasopressin analog, is used to treat central diabetes insipidus, hemostatic disorders such as von Willebrand’s disease, and nocturnal enuresis. We present the case of a 69-year-old man who developed severe hyponatremia during treatment with intranasal desmopressin at 10 µg twice daily for chronic polyuria and nocturia thought to be due to central diabetes insipidus. After 5 months of therapy, the patient noticed progressive fatigue, anorexia, dizziness, weakness, light-headedness, decreased concentration, and new-onset falls. At 6 months of therapy, the patient was brought to the emergency department for altered mental status and was found to be severely hyponatremic with a serum sodium level of 96 mmol/L, down from a value of 134 mmol/L at the initiation of therapy. The intranasal desmopressin was discontinued and the patient was admitted to the intensive care unit where the hyponatremia was slowly corrected over the next week to 132 mmol/L, never increasing by more than 8 mmol/L a day, with careful fluid management. This included infusion of over 11 L of 5% dextrose to account for a high urine output, which peaked at 7.4 L in 1 day. However, while the recommended rate for sodium correction was followed, the patient’s magnetic resonance imaging of the brain obtained after discharge displayed evidence of central pontine myelinolysis. Despite this finding, the patient eventually returned to his baseline mental status with no permanent neurologic deficits.

Cardiovascular autonomic dysfunction in patients with idiopathic diabetes insipidus

INTRODUCTION

Central diabetes insipidus (DI) is a rare disease characterized by the excretion of excessive volumes of dilute urine due to reduced levels of the antidiuretic hormone arginine vasopressin (AVP), caused by an acquired or genetic defect in the neurohypophysis. The aim of this study was to identify any autonomic dysfunction (AD) in patients with DI as a possible cofactor responsible for their reportedly higher mortality.

METHODS

The study involved 12 patients (6 females) with central idiopathic DI and a well-controlled electrolyte balance, and 12 controls matched for age, sex and cardiovascular risk factors, who were assessed using the tilt, lying-to-standing, hand grip, deep breath, Valsalva maneuver and Stroop tests.

RESULTS

The tilt test showed a significantly more pronounced decrease in both systolic (- 20.67 ± 18 vs. - 1.92 ± 6.99 mmHg, p = 0.0009) and diastolic blood pressure (- 10.5 ± 14.29 vs. - 1.5 ± 5 mmHg, p = 0.012) in patients than in controls. Three patients with DI had to suspend the test due to the onset of syncope. The lying-to-standing test also revealed a marked reduction in blood pressure in patients with DI (1.05 ± 0.13 vs. 1.53 ± 0.14, p = 0.0001). Similar results emerged for the Valsalva maneuver (Valsalva ratio, 1.24 ± 0.19 vs. 1.79 ± 0.11, p < 0.0001) and deep breath test (1.08 ± 0.11 vs. 1.33 ± 0.08, p < 0.0001).

CONCLUSIONS

All the principal autonomic tests performed in the study were concordant in indicating that patients with central DI have an impaired autonomic nervous system function despite a normal hydroelectrolytic balance under desmopressin therapy. This impairment may reflect damage to the autonomic system per se and/or the absence of any vasoactive effect of AVP on vascular smooth muscle. In our opinion, patients with central DI should be educated on how to prevent orthostatic hypotension, and pharmacological treatment should be considered for patients with a more marked impairment.

Endocrinopathies and renal outcomes in lithium therapy: impact of lithium toxicity

BACKGROUND

Lithium is the mainstay of treatment for bipolar disorder, mania and an augmentation therapy in patients with treatment resistant depression. It has a narrow therapeutic index, with recognized adverse multi-system and endocrine side effects.

AIM

To assess the impact of lithium therapy, in particular lithium toxicity, on the development of endocrine and renal disorders in a cohort of patients in a single tertiary referral centre in Ireland.

STUDY DESIGN

A retrospective analysis was performed of the prevalence of lithium toxicity and renal, thyroid and parathyroid dysfunction in our study population.

METHODS

We collected laboratory data from the Clinical Chemistry department of the Adelaide and Meath Hospital incorporating the National Children's Hospital (AMNCH), Dublin, Ireland. Our study population included all patients who had at least one serum lithium measurement from January 1st 2000 to December 31st 2014 inclusive.

RESULTS

A total of 580 patients were included in the study. Among our study group, 70 patients (12.1%) had 1 toxic lithium measurement (lithium level >1.2 mmol/l). 27.8% (n > 161) of patients developed stage 3 Chronic kidney Disease (CKD) or higher, which was commoner in those patients who developed toxic lithium levels (P < 0.0001) and in those who developed hypernatraemia (P > 0.0001). 16.2% of patients (n > 94) had one serum sodium >145 mmol/l during follow up. 60 patients(10.3%) had a TSH >10 mU/l, while complete suppression of TSH (<0.05 mU/l) was observed in 22 patients (3.8%) during follow-up. 4% (n > 37) of the study population had ≥1 serum corrected calcium level > 2.55 mmol/l, and 4 patients had biochemical confirmation of primary hyperparathyroidism but PTH levels were only performed in 2.8% (n > 16) of the studypopulation.

CONCLUSION

Stage 3 CKD is common in patients receiving lithium therapy. Lithium toxicity is associated with CKD and hypernatraemia. Thyroid dysfunction and hypercalcaemia are common in patients receiving lithium therapy. Patients receiving lithium therapy require surveillance of renal, thyroid and bone biochemistry.

Adipsic diabetes insipidus in adult patients

INTRODUCTION

Adipsic diabetes insipidus (ADI) is a very rare disorder, characterized by hypotonic polyuria due to arginine vasopressin (AVP) deficiency and failure to generate the sensation of thirst in response to hypernatraemia. As the sensation of thirst is the key homeostatic mechanism that prevents hypernatraemic dehydration in patients with untreated diabetes insipidus (DI), adipsia leads to failure to respond to aquaresis with appropriate fluid intake. This predisposes to the development of significant hypernatraemia, which is the typical biochemical manifestation of adipsic DI.

METHODS

A literature search was performed to review the background, etiology, management and associated complications of this rare condition.

RESULTS

ADI has been reported to occur in association with clipping of an anterior communicating artery aneurysm following subarachnoid haemorrhage, major hypothalamic surgery, traumatic brain injury and toluene exposure among other conditions. Management is very difficult and patients are prone to marked changes in plasma sodium concentration, in particular to the development of severe hypernatraemia. Associated hypothalamic disorders, such as severe obesity, sleep apnoea and thermoregulatory disorders are often observed in patients with ADI.

CONCLUSION

The management of ADI is challenging and is associated with significant morbidity and mortality. Prognosis is variable; hypothalamic complications lead to early death in some patients, but recent reports highlight the possibility of recovery of thirst.

Hormonal Replacement in Hypopituitarism in Adults: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To formulate clinical practice guidelines for hormonal replacement in hypopituitarism in adults.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of six experts, a methodologist, and a medical writer. The American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology co-sponsored this guideline.

EVIDENCE

The Task Force developed this evidence-based guideline using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The Task Force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, the American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines.

CONCLUSIONS

Using an evidence-based approach, this guideline addresses important clinical issues regarding the evaluation and management of hypopituitarism in adults, including appropriate biochemical assessments, specific therapeutic decisions to decrease the risk of co-morbidities due to hormonal over-replacement or under-replacement, and managing hypopituitarism during pregnancy, pituitary surgery, and other types of surgeries.

Managing adipsic diabetes insipidus following anterior communicating artery aneurysm in a subtropical climate

Diabetes insipidus without perception of thirst, as may follow an anterior communicating artery aneurysm, requires prescription of fluid intake as well as desmopressin. The management goal of maintaining a normal serum sodium is rendered more challenging in a humid subtropical environment, where insensible losses are higher.

Heterogenous patterns of recovery of thirst in adult patients with adipsic diabetes insipidus

BACKGROUND

The natural history of adipsic diabetes insipidus (ADI) is not well described, and reports of recovery of thirst are rare.

DESIGN AND METHODS

Case histories presentation. ADI was identified by demonstrating absent thirst and arginine vasopressin (AVP) responses to hypertonic saline infusion.

RESULTS

Twelve patients with ADI were identified (craniopharyngioma 5, anterior communicating artery aneurysm (ACOM) repair 4, congenital 1, neurosarcoidosis 1, prolactinoma 1). Three patients died. Six patients had permanent ADI. Three patients had recovery of thirst, with a heterogenous pattern of recovery. In the first case, ADI had developed after clipping of an ACOM aneurysm. Ten years after surgery; he sensed the return of thirst; repeated hypertonic saline infusion showed recovery of thirst and AVP secretion. In the second case, a 41-year-old female with an intrasellar craniopharyngioma developed post-operative ADI with persistent hypernatremia. Two years post-operatively, she complained of thirst, and hypertonic saline infusion showed normalization of thirst but absent AVP responses, confirming recovery of thirst, but with persistent diabetes insipidus (DI). In the third case, a 29-year-old Caucasian had craniotomy and radiotherapy for craniopharyngioma and developed ADI post-operatively. Eight years post-op, she presented with thirst, seizures and pNa of 112 mmol/l. Hypertonic saline infusion showed persistent DI but thirst responses typical of compulsive water drinking; she has had recurrent hyponatraemia since then.

CONCLUSIONS

We report that 3/12 patients with ADI recovered thirst after longstanding adipsia with heterogenous pattern of recovery. Both the mortality of 25% and the recovery rate of 25% should be considered when planning long-term surveillance.

Central Diabetes Insipidus in Infancy With or Without Hypothalamic Adipsic Hypernatremia Syndrome: Early Identification and Outcome

CONTEXT

Neonatal central diabetes insipidus (CDI) with or without adipsia is a very rare complication of various complex hypothalamic disorders. It is associated with greater morbidity and a high risk of developing both hypernatremia and hyponatremia, due to the condition itself or secondary to treatment with vasopressin analogs or fluid administration. Its outcomes have yet to be evaluated.

OBJECTIVE

To investigate the clinical outcomes of patients with neonatal-onset CDI or adipsic CDI with hypernatremia.

DESIGN, SETTING, AND PARTICIPANTS

All patients diagnosed with neonatal CDI in a university hospital-based observational study and followed between 2005 and 2015 were included and analyzed retrospectively.

MAIN OUTCOME MEASURES

The various causes of CDI were grouped. Clinical outcome and comorbidities were analyzed.

RESULTS

Ten of the 12 patients had an underlying condition with brain malformations: optic nerve hypoplasia (n = 3), septo-optic dysplasia (n = 2), semilobar holoprosencephaly (n = 1), ectopic neurohypophysis (n = 3), and unilateral absence of the internal carotid artery (n = 1). The other two were idiopathic cases. During the median follow-up period of 7.8 (4.9-16.8) years, all but one patient displayed anterior pituitary deficiency. Transient CDI was found in three (25%) patients for whom a posterior pituitary hyperintense signal was observed with (n = 2) and without (n = 1) structural hypothalamic pituitary abnormalities, and with no other underlying cerebral malformations. Patients with permanent CDI with persistent adipsia (n = 4) and without adipsia (n = 5) required adequate fluid intake and various doses of desamino-D-arginine-8-vasopressin. Those with adipsia were more likely to develop hypernatremia (45 vs 33%), hyponatremia (16 vs 4%) (P < .0001), and severe neurodevelopmental delay (P < .05) than those without adipsia. Comorbidities were common. The underlying cause remains unknown at the age of 23 years for one patient with CDI and normal thirst.

CONCLUSION

Neonatal CDI may be transient or permanent. These vulnerable patients have high rates of comorbidity and require careful monitoring.