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Background: Acute lymphoblastic leukemia is the most common pediatric malignancy, characterized by fever, anemia, hemorrhage, and symptoms brought on by blasts infiltrating organs., Case Presentation: This is a case report of a 9-year-old Asian patient with acute lymphoblastic leukemia who presented with polyuria alone as a presenting feature without any other clinical manifestation; primary renal disease or inherited metabolic disease was highly suspected. However, the water deprivation test and water deprivation pressurization test suggested nephrogenic diabetes insipidus, and the renal biopsy displayed diffuse lymphocytic infiltration in the renal interstitium. Bone marrow aspiration was performed immediately, and a comprehensive diagnosis of B-lymphoblastic leukemia was finally made., Conclusions: Renal infiltration with leukemic blasts mostly remains asymptomatic, but our case suggests that it can present with nephrogenic diabetes insipidus. This case fully demonstrates that the presentation of extramedullary infiltration in acute lymphoblastic leukemia is varied. When the patient has renal diabetes insipidus as the first symptom, the possibility of hematological tumor infiltration should be considered when finding the cause, and timely bone marrow cytology should be performed., (© 2024. The Author(s).)

A 35-year-old otherwise healthy gentleman from Togo, was referred as a 'walk-in' to our clinic with polyuria and polydipsia, and a glycated haemoglobin (Hba1c) of 119 mmol/mol (13.1%). The patient also noted 5kg weight loss over a short span of time. He had a significant family history of Type 2 Diabetes Mellitus (T2DM). Initial blood tests revealed a blood glucose of 22.84 mmol/L, with positive ketones (1.2 mmol/L). Urinalysis showed glycosuria (1000 mg/dL) but was negative for nitrites and white cells. Renal, liver and thyroid function tests were all within normal limits. He had mild metabolic acidosis.

We present a case of a young man with a new-onset supraventricular arrhythmia accompanied by polyuria and natriuresis with subsequent renal salt-wasting causing hypovolemic hyponatremia. Resolution of the electrolyte imbalance occurred only after successful atrial flutter ablation., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Diabetes mellitus (DM) and arginine vasopressin deficiency (AVP-D) are characterized by polyuria. Marfan syndrome is an autosomal dominant disorder caused by pathogenetic variants in FBN1. Here, we report a patient with type 2 diabetes mellitus, AVP-D, and Marfan syndrome. Although the coexistence of type 2 diabetes mellitus and AVP-D is rare, for those patients with type 2 diabetes mellitus, the existence of AVP-D should be considered when polyuria is not in accordance with the blood glucose levels, especially for those with a low urine specific gravity. Specific symptoms or signs help to identify Marfan syndrome early, and genetic testing of the FBN1 pathogenetic variant helps to make a definitive diagnosis., (© 2024 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.)

Polyuria-polydipsia syndrome is a frequent symptom in pediatrics, primarily attributed to diabetes mellitus. In the context of diabetes insipidus, this syndrome can stem from central or nephrogenic factors. Sjögren's syndrome, an uncommon autoimmune disease in children, can affect multiple organs. Kidney involvement as described in adults is usually related to glomerular or tubular impairment, often linked to distal tubular acidosis. As a kidney involvement during childhood, Sjögren's syndrome has rarely been reported. Hereby, we present the case of Sjögren's syndrome revealed by polyuria-polydipsia syndrome in a 10-year-old boy., (© 2023. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Objective: To determine the prevalence of nocturnal polyuria (NP) in patients with spinal cord injury (SCI) during three different particular phases, and investigate the impact of injury level and injury type on the prevalence of NP., Design: A cross-sectional study., Setting: Neurogenic Bladder Study Group from six different rehabilitation centers across the country., Participants: 40 patients with SCI., Outcome Measures: Patients were divided into three groups according to mobilization phase; 1st group included patients confined to bed ( n  =   14), 2nd group included patients sitting on a wheelchair ( n  =   19) and 3rd group included patients standing with an assistive ambulation device ( n  =   7). NP was assessed by nocturnal polyuria index (NPi) and nocturnal urine production (NUP) indexes., Results: No significant difference was found between the groups (P   =   0.312 for NPi and P   =   0.763 for NUP) in terms of the presence of NP according to their mobilization phase. The night and 24-hour urine volumes showed no significant difference between the groups (P   =   0.907 and P   =   0.395 respectively). The NPi and NUP values did not show a significant difference between male and female patients (P   =   0.826, P   =   0.364 respectively), patients with the injury level of ≥T6 and

Purpose: Myelomeningocele is the most severe form of spina bifida. Management of urologic consequences of spina bifida is life long, demanding and costly for both the patient and the public health system. There is a paucity of data in the literature regarding concentration defects and their consequences on this disease. This paper aims to describe retrospectively the effect of early onset clean intermittent catheterization (CIC) in on the severity of urinary concentration defects in myelomeningocele patients with neurogenic bladder in a retrospective observational study., Materials and Methods: In this 10-year retrospective cohort study, children with myelomeningocele were selected with the Convenience sampling method. Demographic characteristics, polyuria index ratio (PIR) defined as 24 hour urine output of each patient divided by the maximum normal urine output of the same patient in a healthy state, and nocturnal polyuria index (NPI) were compared between early starters (< 2 years old) or late starters (≥ 2 years old) groups., Results: Seven patients who underwent cystoplasty were excluded and 130 patients (63.8% male, 5.4 ± 3.2 years old, 14.3 ± 2.83 Kg, 28.5% early onset CIC) were investigated. PIR > 1 in inset (1.7 ± 0.2 vs. 2.2 ± 0.5, P = 0.021) and outset (1.5 ± 0.32 vs. 2.5 ± 0.7, P = 0.004) were lower in early starters group than in late starters group. NPI in inset (0.2 ± 0.007 vs. 0.32 ± 0.10, P = 0.018) and outset (0.25 ± 0.15 vs. 0.42 ± 0.095, P = 0.007) were also lower in the early starters group. No further adverse events were reported during the follow-up period., Conclusion: Early onset CIC is more effective than late-onset CIC in preserving the urinary ability of kidneys in myelomeningocele patients.

Children with sellar and/or suprasellar lesions may develop central diabetes insipidus with subsequent inappropriate antidiuretic hormone secretion. An increased incidence of polyuria, natriuresis, and hyponatremia has been reported in some cases, which make up the diagnostic triad of cerebral salt wasting syndrome. Here we report the clinical course of 7 patients with a history of acute central nervous system injury and central diabetes insipidus followed by cerebral salt wasting syndrome. Treatment included the sequential use of parenteral saline solution, oral sodium chloride, desmopressin, mineralocorticoids, and even thiazides. Due to persistent polyuria and hyponatremia, ibuprofen was added. As a result of this sequential therapeutic regimen, daily urine output reduced significantly from 10 mL/kg/h to 2 mL/kg/h over an average period of 5 days, together with a normalization of natremia (from 161 mEq/L to 143 mEq/L) over an average period of 9 days. No treatment-related adverse effects were observed in any case., (Sociedad Argentina de Pediatría.)

Background: Distinguishing between arginine vasopressin (AVP) deficiency and primary polydipsia is challenging. Hypertonic saline-stimulated copeptin has been used to diagnose AVP deficiency with high accuracy but requires close sodium monitoring. Arginine-stimulated copeptin has shown similar diagnostic accuracy but with a simpler test protocol. However, data are lacking from a head-to-head comparison between arginine-stimulated copeptin and hypertonic saline-stimulated copeptin in the diagnosis of AVP deficiency., Methods: In this international, noninferiority trial, we assigned adult patients with polydipsia and hypotonic polyuria or a known diagnosis of AVP deficiency to undergo diagnostic evaluation with hypertonic-saline stimulation on one day and with arginine stimulation on another day. Two endocrinologists independently made the final diagnosis of AVP deficiency or primary polydipsia with use of clinical information, treatment response, and the hypertonic-saline test results. The primary outcome was the overall diagnostic accuracy according to prespecified copeptin cutoff values of 3.8 pmol per liter after 60 minutes for arginine and 4.9 pmol per liter once the sodium level was more than 149 mmol per liter for hypertonic saline., Results: Of the 158 patients who underwent the two tests, 69 (44%) received the diagnosis of AVP deficiency and 89 (56%) received the diagnosis of primary polydipsia. The diagnostic accuracy was 74.4% (95% confidence interval [CI], 67.0 to 80.6) for arginine-stimulated copeptin and 95.6% (95% CI, 91.1 to 97.8) for hypertonic saline-stimulated copeptin (estimated difference, -21.2 percentage points; 95% CI, -28.7 to -14.3). Adverse events were generally mild with the two tests. A total of 72% of the patients preferred testing with arginine as compared with hypertonic saline. Arginine-stimulated copeptin at a value of 3.0 pmol per liter or less led to a diagnosis of AVP deficiency with a specificity of 90.9% (95% CI, 81.7 to 95.7), whereas levels of more than 5.2 pmol per liter led to a diagnosis of primary polydipsia with a specificity of 91.4% (95% CI, 83.7 to 95.6)., Conclusions: Among adult patients with polyuria polydipsia syndrome, AVP deficiency was more accurately diagnosed with hypertonic saline-stimulated copeptin than with arginine-stimulated copeptin. (Funded by the Swiss National Science Foundation; CARGOx ClinicalTrials.gov number, NCT03572166.)., (Copyright © 2023 Massachusetts Medical Society.)

Activity-based recovery training (ABRT) reverses spinal cord injury (SCI) induced polyuria and alterations of biomarkers involved with fluid balance, including expression levels of kidney vasopressin 2 receptors. However, void volumes do not return to pre-injury baseline levels, indicating a combinatorial approach may be necessary., In the current study, acute effects of a pharmacological intervention versus placebo were examined in male rats that had received 70 daily ABRT sessions. The treatment, desmopressin (DDAVP - synthetic analogue of arginine vasopressin), an antidiuretic therapy used for the management of bedwetting in children and central diabetes insipidus, has previously shown some promise in a few limited cohorts of SCI individuals having nocturnal polyuria., A total of 70 sessions of ABRT over a 10-week timeframe again reduced the overproduction of urine, but not completely to pre-SCI baseline levels. DDAVP treatment maintained but did not further reduce the level of urine output in the ABRT group without continuous exercise, demonstrating either intervention/treatment alone is effective, despite no additive effect. Although intake did not change from pre-injury levels despite polyuria, DDAVP treatment also reduced drink volume., Further studies are needed as the mechanisms underlying changes in fluid and solute balance are likely multi-factorial involving a complex interaction between the neural (both central and peripheral) control of systems mediating thirst, urinary output, and cardiovascular regulation.

Background: Delayed cerebral ischemia is a clinical entity commonly encountered in patients presenting with acute neurological injury and is often complicated by dysnatremias, such as the cerebral salt wasting syndrome. In this case report, we described an exceptional case of polyuria attributed to an initial cerebral salt wasting phenomenon and iatrogenic-induced medullary washout., Case Presentation: A 53-year-old woman was admitted to our hospital for the management of a Modified Fisher scale grade 4 subarachnoid hemorrhage due to a ruptured posterior communicating aneurysm. She was initially managed with coil embolization and external ventricular drain due to secondary hydrocephalus. Throughout the course of her hospitalization, she developed severe polyuria reaching up to 40L per day. To keep up with the excessive urinary losses and maintain appropriate cerebral perfusion, fluid replacement therapy was adjusted every hour, reaching up to 1.3 L of crystalloid per hour in addition to aminergic support. An initial diagnosis of partial diabetes insipidus, followed by a cerebral salt wasting syndrome was suspected. While the urine output continued to increase, her serum urea concentration progressively decreased to a point of almost being undetectable on day 9. At that time, the presence of an interstitial medulla washout was hypothesized. Various pharmacological and non-pharmacological interventions were progressively introduced to regain normal renal homeostasis, including non-steroidal anti-inflammatory drugs, fludrocortisone, oral urea and high-protein intake. Medications were progressively weaned, and the patient was successfully discharged from the ICU., Conclusions: Cerebral salt wasting should be considered in the initial differential diagnosis of a patient presenting with polyuria in the context of acute neurological injury. Early recognition of this entity is critical to quickly implement proper management. However, as shown in this case report, the concomitance of delayed cerebral ischemia may complexify that management., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Introduction and Hypothesis: Data from a large US population-based, cross-sectional, epidemiological study (the EpiNP Study) were used to assess the symptoms and bother experienced by women with nocturnal polyuria (NP)., Methods: Consenting participants recruited from an online panel completed the baseline EpiNP survey online (Lower Urinary Tract Symptoms Tool and urological comorbidities). All reporting ≥2 voids/night and a random sample of 100 respondents, each reporting 0 or 1 void/night were asked to complete a 3-day web-based bladder diary recording time, volume, and urgency rating of each void. NP was calculated by the proportion of urine production that occurred during nocturnal hours using a Nocturnal Polyuria Index (NPI33) threshold of >0.33 or nocturnal urine production of >90 ml/h (NUP90). The frequency of participants reporting LUTS and bother was determined by age and NP: idiopathic NP, NP associated with overactive bladder (NPOAB), NP associated with comorbidities (NPCom), and no NP (did not meet NP criteria)., Results: A total of 5,290 women completed the baseline survey. Mean age (range) was 54.9 (30-95) years; 1,841 (34.8%) reported ≥2 nocturnal voids. The prevalence of LUTS increased across the lifespan; however, bother associated with each LUTS decreased with increasing age. The percentage of women rating bother by nocturia episodes ≥2 "> somewhat" ranged from 40.3% to 68.3%, with bother ratings highest in the NPOAB and No NP groups., Conclusions: NP is prevalent in women with considerable bother and is often associated with other urinary symptoms. Multifactorial causes and potential treatments of NP should be considered, particularly at a later age., (© 2023. The International Urogynecological Association.)

Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Post-Obstructive Diuresis (POD) is a polyuria that occurs following the release of an obstruction from the urinary tract that prevents the flow of urine. POD requires prompt diagnosis to avoid complications. Although its pathophysiology is better understood, there is little scientific evidence for its treatment. Restoration of renal homeostasis requires correction of blood volume and electrolyte disturbances to prevent complications, which can be serious. In this article, we propose a synthesis of knowledge on the subject, as well as a management strategy., (Copyright © 2023 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier Masson SAS. All rights reserved.)

The relief of the impediment to urinary flow is the treatment of acute kidney failure due to urinary tract obstruction. However, there is a risk of inducing massive polyuria, which can be self-limited or produce severe contraction of the intravascular volume with pre-renal acute kidney failure and alterations in the internal environment. Polyuria, urine output > 3 L/d or > 200 mL/min for more than 2 hours, can have multiple causes, and can be classified as osmotic, aqueous or mixed. Post-obstructive polyuria obeys different pathogenic mechanisms, which overlap and vary during a patient's evolution. Initially, there is a decrease in vasoconstrictor factors and an increase in renal blood flow, which, added to the excess of urea accumulated, will cause intense osmotic diuresis (osmotic polyuria due to urea). Added to these factors are the positive sodium and water balance during acute renal failure, plus the contributions of crystalloid solutions to replace diuresis (ionic osmotic polyuria). Finally, there may be tubular dysfunction and decreased solutes in the renal medullary interstitium, adding resistance to the action of vasopressin. The latter causes a loss of free water (mixed polyuria). We present the case of a patient with post-obstructive polyuria where, by analyzing the clinical symptoms and laboratory alterations, it was possible to interpret the mechanisms of polyuria and administer appropriate treatment for the pathogenic mechanism.

Central nervous system germ cell tumors (CNSGCTs) are rare neoplasms which usually develop in the midline structures. They are occasionally involved in off-midline structures of the brain. Here, we report an extremely rare case of an intracranial germinoma in the lateral ventricle. The patient was a 10-year-old boy with a 1-year history of polydipsia and polyuria. Brain magnetic resonance imaging (MRI) showed a relatively homogeneously enhancing lesion in the lateral ventricle, and the posterior pituitary gland was not hyperintense on T1-weighted imaging. Subependymoma was suspected, and tumor removal operation was performed; however, because the intraoperative pathological investigation revealed germinoma, we could only perform partial removal of the tumor. Postoperative histology also confirmed germinoma. Then, the patient received chemotherapy, followed by radiation therapy. MRI showed no recurrence for 6 years after treatment. Intracranial germinoma in the lateral ventricle is extremely rare. The diagnosis is occasionally challenging, especially when the tumors are located in atypical locations. This paper presents a literature review of previously described CNSGCTs of the lateral ventricle to improve awareness of CNSGCTs in atypical locations. We also consider the relationship between imaging findings and clinical manifestations., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction/background: The pulse width (PW) parameter in sacral neuromodulation (SNM) is understudied, with no evidence-based guidance available on optimal PW for urinary indications. The aim of this prospective, randomized, single-blinded, 3 × 3 cross over design study was to estimate the effect of two PW settings (60 µs, 420 µs) compared to the industry standard (210 µs) on SNM efficacy, quality of life, and device parameters in patients who were stable and satisfied with their SNM treatment., Methods/materials: Eligible patients were previously implanted and had urge incontinence or urgency-frequency with satisfaction on SNM at time of enrollment. Patients completed a 3-day voiding diary, validated questionnaires, and device interrogations with sensory threshold assessment at baseline and after a 4-week period on each of the three PW settings, to which they were randomized. Eighteen participants completed the study, as called for by power analysis., Results: Eighteen patients were enrolled in the study. Mean age was 68 years and implant duration at the time of participation was 4.4 years. While PW variations did not produce significant differences in overall objective outcomes, device parameters, including sensory threshold amplitude and battery life differed significantly. Shortened PW necessitated higher amplitude while conserving battery life. Stimulus sensation location, quality, and intensity did not differ between PW. Standard PW was chosen by 11 patients after the study, 5 chose extended, and 2 chose shortened. Those who chose alternative PW achieved significant reductions in urinary frequency from enrollment -2.23 voids/day (p = 0.015). Upon sub-analysis, patients reporting "much better" or "very much better" on extended PW achieved significant reductions in urinary frequency and nocturia at 5.6 and 0.4, compared to 8.5 and 2.16 at baseline (p = 0.005, p = <0.001). Whereas those reporting "much better" or "very much better" on shortened PW achieved significant reductions in urinary frequency at 5.15 compared to 7.35 (p = 0.026). There were no adverse events or complications., Conclusions: Overall SNM effectiveness was unchanged with alternative PW; however, 39% of patients preferred alternative to standard PW and achieved significant improvements in urinary symptoms with such. Shorter PW can also provide savings in estimated battery life without sacrificing therapeutic efficacy., (© 2023 Wiley Periodicals LLC.)

Objectives: To explore the impact of nocturnal polyuria (NP) on health-related quality of life (HRQoL), work productivity, mental health, fatigue, bother, and daytime sleepiness., Materials and Methods: This large-scale, US population-representative epidemiologic study was conducted in two parts: a web-based survey and 3-day bladder diary. Consenting participants completed the baseline Epidemiology of NP (EpiNP) survey online (Lower Urinary Tract Symptoms [LUTS] Tool, comorbidities, burden, and multiple HRQoL measures). Participants who reported ≥2 voids/night, and a random sample of 100 respondents each reporting 0 or 1 void/night, were sent urine measurement containers and asked to complete the 3-day bladder diary. NP was defined as Nocturnal Polyuria Index >0.33 (NPI33) or nocturnal urine production >90 ml/h (NUP90). Five subgroups were created: Idiopathic NP (NP with no underlying cause), NP associated with symptoms of overactive bladder (NPOAB) or bladder outlet obstruction (NPBOO; men only), NP associated with other comorbidities (NPCOM; e.g., diabetes, hypertension, heart disease, sleep apnea), and no NP (did not meet NP criteria)., Results: A total of 4893 men and 5297 women completed the EpiNP survey; mean age was 54.4 (SD = 14.7). Significantly greater patient burden (p < 0.0001) was evidenced in the nocturia group (≥2 voids/night) versus no nocturia group (0-1 void/night) on daily impact of nocturia, LUTS Bother, prostate symptoms (men only), work productivity, physical and mental health component scores, depression, fatigue, and daytime sleepiness. NP subgroup analyses showed men in the NPBOO group and women in the NPOAB group reported the greatest impact on LUTS bother, fatigue, physical health, work productivity impairment, daytime sleepiness, and depression (women only)., Conclusion: This was the first large-scale, epidemiologic study to explore the impact of different forms of NP on patients' HRQoL. Findings demonstrate that NP associated with other urologic or comorbid conditions appears to have greater patient burden than idiopathic NP, in particular for women., (© 2023 Wiley Periodicals LLC.)

Nocturia is the complaint that an individual has to wake up at night one or more times to urinate. It is a frequent condition among older adults and entails detrimental effects with regard to sleeping, sexual activity, comfort, depression, mental function and vitality. It is clinically important to distinguish it from global polyuria, defined as a urinary rate ≥ 125 ml/h (3000 ml/day), as well as from nocturnal polyuria, which is an abnormally large volume of urine during sleep associated with a decreased daytime urine production. A Frequency Volume Chart (FVC), overnight water deprivation test with renal concentrating capacity test, and the nocturnal bladder capacity index are some of the methods that help establish the underlying pathology of this condition and hence define an adequate treatment plan., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Introduction: Patients with lower urinary tract symptoms (LUTS) can be subcategorized into polyuria, normal or oliguria groups. Polyuria may be caused by pathologies including diabetes mellitus (DM), chronic kidney disease (CKD), diabetes insipidus (DI), or primary polydipsia (PPD). While fluid restriction is appropriate for some, doing so in all may result in serious complications. This study investigates the prevalence of these pathologies in LUTS patients with polyuria., Materials and Methods: Two databases were retrospectively queried for men and women who filled out a lower urinary tract symptom score (LUTSS) questionnaire, 24-h bladder diary (24HBD) and were polyuric (>2.5 L/day). Patients were divided into four groups: poorly controlled DM, DI, an CKD grade 3 and PPD. One-way analysis of variance compared 24HBD and LUTSS questionnaires. Pearson correlation examined LUTSS and bother with 24-h voided volume (24 HVV), maximum voided volume (MVV) and total voids., Results: Among 814 patients who completed a 24HBD, 176 had polyuria (22%). Of the patients with complete data, 7.8% had poorly-controlled DM, 3.1% had DI, 4.7% had CKD grade 3% and 84.4% had PPD. Amongst the four different sub-groups, significant differences were seen in 24 HVV (p < 0.001), nocturnal urine volume (NUV) (p < 0.001), MVV (p = 0.003), daytime voids (p = 0.05), nocturnal polyuria index (NPi) (p < 0.001) and nocturia index (Ni) (p = 0.002). Significance was also seen between LUTSS and bother subscore (r = 0.68, p < 0.001), LUTSS and total voids (r = 0.29, p = 0.001) and bother sub-score and total voids (r = 0.21, p = 0.019)., Conclusions: 22% of patients with LUTS were found to have polyuria based on a 24HBD. Within this cohort, four sub-populations were identified as being demonstrating statistically significant differences in 24 HVV, NUV, MVV, daytime voids, NPi and Ni. Identifying the underlying etiology of polyuria should be carried out to safely treat patients with LUTS., (© 2022 The Authors. Neurourology and Urodynamics published by Wiley Periodicals LLC.)

BACKGROUND Central diabetes insipidus (CDI) is a rare disorder characterized by large volumes of dilute urine because of a lack of antidiuretic hormone. Co-existing CDI and diabetes mellitus without inherited disorders such as Wolfram syndrome are rare. It is both important and challenging to diagnose this combination because the 2 conditions present with thirst, polydipsia, and polyuria. A few cases of CDI developing in patients with type 2 diabetes mellitus (T2D) have been reported. We report an unusual case of CDI that developed in an older patient with T2D. The aims of this report are to share the clinical course and discuss clues to the early diagnosis of CDI in T2D. CASE REPORT A 70-year-old Japanese woman developed T2D with hyperglycemia symptoms, including thirst, polydipsia, and polyuria. After starting medical treatment, the hyperglycemia and its symptoms improved. The glycated hemoglobin level decreased from 9% to 6%. However, 5 years later (at 75 years of age), she re-exhibited thirst, polydipsia, and polyuria despite stable glycemic control. Her urine volume was large (6.3 L/day). A urine glucose test was negative. The plasma osmolality was high (321 mOsm/kg), while the urinary osmolality was low (125 mOsm/kg). A significant increase in urinary osmolality following vasopressin administration indicated a diagnosis of CDI. Desmopressin therapy effectively relieved the symptoms. CONCLUSIONS This case highlights the need to consider CDI as a rare but important comorbid disorder in patients with diabetes mellitus, including T2D, particularly those presenting with thirst, polydipsia, and polyuria despite well-controlled glycemia.

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., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

To the Editor, Nocturia is a significantly underestimated medical problem that affects seriously patients' quality of life, work engagement, productivity, and overall life conditions per se. Nocturia is a common condition, proven to be the most bothersome for patients with Lower Urinary Tract Symptoms (LUTS). People with two or more events of micturition per night have a significant increase in mortality rate and an increased risk of fall-related fractures if they visit the toilet two or more times per night [...].

Background: The prevalence of nocturnal polyuria (NP), which is passing large volumes of urine during the main sleep period, has been investigated primarily in middle-aged to older men. There is thus a gap in the NP evidence base for women and for younger individuals., Objective: To estimate the prevalence of nocturia due to NP in the USA., Design, Setting, and Participants: This large epidemiologic study used a US population-representative sample of men and women aged ≥30 yr to assess the prevalence of NP (NCT04125186)., Outcome Measurements and Statistical Analysis: Consenting participants completed an online survey (Lower Urinary Tract Symptoms Tool and comorbidities). All who reported two or more voids per night and 100 random respondents each reporting no or one void per night were asked to complete a 3-d bladder diary. Two NP definitions were used: nocturnal urine production >90 ml/h (NUP90) and Nocturnal Polyuria Index >0.33 (NPI33). Crude and population-adjusted prevalence results were calculated from completed diaries for the following subgroups by sex and age: idiopathic NP; NP with overactive bladder (NP-OAB) or bladder outlet obstruction (NP-BOO; men only); NP associated with other comorbidities; and no NP (did not meet the NPI33 or NUP90 definition)., Results and Limitations: Among the 10,190 respondents who completed the survey, the mean age was 54.4 yr (range 30-95); 3,339 reported two or more nocturnal voids and 1,763 completed the 3-d diary (response rate 49.3%). The adjusted overall NP prevalence was 31.5% among men and 38.5% among women using the NPI33 definition, and 23.8% among men and 18.1% among women using NUP90. The adjusted idiopathic NP prevalence was lower among men (NPI33: 5.2%; NUP90: 1.4%) than among women (NPI33: 9.8%; NUP90: 4.0%). The prevalence of idiopathic NP decreased with age as NP associated with other possible causes increased with age in men (most common, BOO) and women (most common, OAB)., Conclusions: This is the first population-based study of NP prevalence to include men, women, and young adults. NP is common; a multifactorial etiology should be considered, particularly as age increases., Patient Summary: In this population-based US study, we examined the frequency of nighttime urination among men and women aged ≥30 y and older. We found that nighttime urination is common among men and women. Many conditions can lead to increased nighttime urination as people age., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: Water and electrolyte disturbances are common after pituitary surgery and can generally be classified into transient hypotonic polyuria and transient or permanent diabetes insipidus (DI). The prevalence varies in the literature between 31-51% for transient hypotonic polyuria, 5.1-25.2% for transient DI, and 1-8.8% for permanent DI., Objective: The aim of this study was to identify the prevalence of water and electrolyte disturbances with polyuria and the preoperative and postoperative predictive factors in patients undergoing surgery with an extended endoscopic endonasal approach., Material and Methods: This retrospective observational descriptive study included 203 patients with a diagnosis of pituitary adenoma who underwent their first transsphenoidal surgery via the extended endoscopic endonasal approach between April 2013 and February 2020. The diagnosis of water and electrolyte disturbances was based on the criterion for polyuria (>4 ml/kg/h). Postoperative polyuria was defined as those cases diagnosed during the immediate postsurgical period that resolved prior to discharge. Transient DI included all cases with a duration of less than 6 months but still present at hospital discharge, and permanent DI included cases lasting more than 6 months., Results: The overall prevalence of water and electrolyte disorders was 30.5% (62), and the prevalence of postoperative polyuria was 23.6% (48). The median number of desmopressin doses administered to patients with postoperative polyuria was one dose (interquartile range [IQR] 1-2), and thus the median duration of treatment was 0 days. The median initiation of desmopressin was the second day after surgery (IQR 1-2). The overall prevalence of DI was 6.89%. Among the patients with transient DI, the duration was less than 3 months in three patients (1.47%), and between 3 and 6 months in two (0.98%). Nine patients had permanent DI (4.43%). (4.43%)., Conclusions: The prevalence of electrolyte disturbances in our study was high, although similar to that found in the literature. Most of the cases were transient hypotonic polyuria that resolved within one day. The prevalence of transient DI in our cohort was lower than that described in the literature, while permanent DI was similar., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Canelo Moreno, Dios Fuentes, Venegas Moreno, Remón Ruíz, Muñoz Gómez, Piñar Gutiérrez, Cárdenas Valdepeñas, Kaen and Soto Moreno.)

Purpose: Prevalence data on nocturnal polyuria (NP), nocturia caused by overproduction of urine during sleep, is primarily limited to men and varies by NP definition. This U.S.-representative epidemiological study of men and women ≥30 years old assessed the prevalence of NP., Materials and Methods: Consenting participants completed the baseline EpiNP (Epidemiology of Nocturnal Polyuria) survey (eg Lower Urinary Tract Symptoms Tool, comorbidities). All reporting ≥2 voids/night and a target of 100 random respondents reporting 0 or 1 void/night were asked to complete 3-day bladder diaries. NP was defined as nocturnal polyuria index (NPI) >0.33 (NPI33) and nocturnal urine production >90 ml/hour (NUP90). Extrapolated prevalence was stratified by sex and subgroups: idiopathic (without underlying causes), associated with overactive bladder (NPOAB), bladder outlet obstruction (NPBOO; men) and comorbidities. Voided volumes and timing, including first uninterrupted sleep period, were assessed by subgroup., Results: A total of 10,190 individuals completed the baseline survey; mean age (range) was 54.4 (30-95). A total of 3,938 individuals were invited to complete the diary; 1,763 (49.3%) completed 3-day bladder diaries. Urine production (maximum nighttime volume, total volume, nocturnal urine production, nocturia index) was higher in both men and women with idiopathic NP and comorbidities. The median number of nighttime voids was greatest for NPBOO in men and NPOAB in women. Bother associated with nighttime voiding differed by NP subgroup but was highest in NPBOO for men (NPI33: 69.6%; NUP90: 71.1%) and NPOAB for women (NPI33: 67.5%; NUP90: 66.0%)., Conclusions: This population-based NP prevalence study including men and women characterizes NP subgroups and provides insights into nocturia treatment by emphasizing factors influencing urine production versus factors influencing bladder capacity.

We report a case of a 40-year-old woman who developed profound polyuria (>25 L urine output) immediately after initiation of venoarterial (VA) extracorporeal membrane oxygenation (ECMO). Investigations into the cause determined the polyuria was due to marked natriuresis (>85 g of sodium excreted in 1 day). This natriuresis persisted despite low cardiac filling pressures and high-negative ECMO venous pressures, suggesting clinical hypovolemia due to pressure natriuresis from locally high pressures at the renal artery due to arterial ECMO inflow. As ECMO flows were decreased, polyuria and natriuresis resolved. To our knowledge, this is the first description of VA-ECMO-associated salt wasting., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2022.)

Presented case demonstrates a rare diencephalic pathology - adipsic diabetes insipidus (ADI) with severe hypernatremia in a 58-year-old woman after ttranssphenoidal removal of stalk intraventricular craniopharyngioma. ADI was diagnosed because of hypernatremia (150-155 mmol/L), polyuria (up to 4 liters per day) and absence of thirst. Normalization of water-electrolyte balance occurred on the background of desmopressin therapy and sufficient hydration in postoperative period. After release from the hospital, the patient independently stopped desmopressin therapy and did not consume an adequate amount of fluid of the background of polyuria. This led to severe hypernatremia (155-160 mmol/L) and rough mental disorders.Patients with ADI need closely monitoring of medical condition and water-electrolyte parameters, appointment of fixed doses of desmopressin and adequate hydration.

Competing Interests: Declaration of interests We declare no competing interests.

Polyuria is a common clinical condition characterized by a urine output that is inappropriately high (more than 3 L in 24 h) for the patient's blood pressure and plasma sodium levels. From a pathophysiological point of view, it is classified into two types: polyuria due to a greater excretion of solutes (urine osmolality >300 mOsm/L) or due to an inability to increase solute concentration (urine osmolality <150 mOsm/L). Sometimes both mechanisms can coexist (urine osmolality 150-300 mOsm/L). Polyuria is a diagnostic challenge and its proper treatment requires an evaluation of the medical record, determination of urine osmolality, estimation of free water clearance, use of water deprivation tests in aqueous polyuria, and measurement of electrolytes in blood and urine in the case of osmotic polyuria., (Copyright © 2021 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.)

Polyuria is found in patients with spinal cord injury (SCI). However, the underlying cellular and molecular mechanism is unknown. Here, we show that mice had elevated urine for 7 days after T 10 contusion. Using multi-photon confocal microscopy, we performed intra-vital imaging experiments to evaluate water reabsorption in kidney tubules by examining fluorescent intensity in the lumen of the distal tubule from live mice. The data show that SCI significantly reduced the concentrating function of kidney tubules. The reduced water reabsorption appears to be mediated by atrial natriuretic peptide (ANP) because SCI increased the expression levels of both ANP and natriuretic peptide receptor A (NPR-A) in the kidney cortex. Our patch-clamp single-channel recordings from split-open distal tubules show that SCI decreased the activity of the epithelial sodium channel (ENaC). Western blot combined with confocal microscopy data show that the levels of 70 kD γ-ENaC, which is an active isoform because of proteolytic cleavage, were significantly reduced in distal tubule principal cells. An NPR-A inhibitor (A71915) given intravenously eliminated the effects of SCI on ENaC and polyuria. These data together with previous studies suggest that SCI causes polyuria, probably by reducing ENaC activity through elevating ANP and NPR-A. Further investigation of the signal transduction pathways may provide useful information for discovering an efficient drug to treat SCI-induced polyuria.

Polyuria and polydipsia are rare, but significant, manifestations of several different diseases of horses. Causes can be endocrine, iatrogenic, psychogenic, infectious, or toxic in nature and can also be due to primary renal disease or diseases of other organs, such as the liver. Although numerous causes of polyuria and polydipsia in horses exist, the most common conditions include chronic kidney disease, pituitary pars intermedia dysfunction, and psychogenic polydipsia with secondary polyuria. Additional testing is dictated by history, other clinical signs, and the results of blood work and/or urinalysis. Prognosis for horses with polyuria and/or polydipsia varies significantly based on the underlying cause., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: Postmenopausal nocturia is poorly understood. This study aimed to identify hormonal and lifestyle factors associated with nocturia and to understand the relative contribution of altered urine production and bladder storage dysfunction in women., Design, Setting, Population and Methods: Women ≥40 years presenting to public continence services were enrolled in a cross-sectional study. A total of 153 participants completed a hormone status questionnaire, a validated nocturia causality screening tool and a 3-day bladder diary. Descriptive statistics and logistic regression models for nocturia severity and bladder diary parameters were computed., Results: Overall, 91.5% reported nocturia, 55% ≥2 /night. There was a difference of 167.5 ml (P < 0.001) in nocturnal urine volume between women with nocturia ≥2 (median 736 ml) versus less often (517 ml). Significant predictors of self-reported disruptive nocturia were age (odds ratio [OR] 1.04, 95% CI 1.002-1.073) and vitamin D supplementation (OR 2.33, 95% CI 1.11-4.91). Nocturnal polyuria was significantly more common with nocturia ≥2 compared with less frequent nocturia (P < 0.002). Exercise for 150 minutes a week was protective for nocturnal polyuria (OR 0.22, P = 0.001). Nocturia index >1.3 was significantly predicted by age (OR 1.07, P < 0.001), regular exercise (OR 0.41, P = 0.036), day flushes (OR 4.00, P = 0.013) and use of vitamin D (OR 2.34, P = 0.043). Maximum voided volumes were significantly lower with nocturia ≥2 versus less often (night: 268 ml versus 350 ml; day: 200 ml versus 290 ml)., Conclusions: Bothersome nocturia in postmenopausal women is associated with changes to both nocturnal diuresis and bladder storage. Regular physical activity, prolapse reduction and oestrogen replacement may be adjunctive in managing bothersome nocturia in women., (© 2021 John Wiley & Sons Ltd.)

Central diabetes insipidus (CDI) is a rare endocrine disease deriving from an insufficient production or secretion of anti-diuretic hormone. Recently, CDI has been reported as a rare side effect triggered by immune checkpoint inhibitors (ICI) in cancer patients. Despite its current rarity, CDI triggered by ICI is expected to affect an increasing number of patients because of the expanding use of these effective drugs in a growing number of solid and hematologic malignancies. An appropriate assessment of the severity of adverse events induced by anticancer agents is crucial in their management, including dosing adjustment and temporary withdrawal or discontinuation treatment. However, assessment of the severity of CDI induced by ICI may be challenging, as its main signs and symptoms (polyuria, dehydration, weight loss, and hypernatremia) can be incompletely graded. Indeed, the current grading system of toxicity induced by anticancer treatments does not include polyuria. Additionally, dehydration in patients affected by diabetes insipidus, including ICI-induced CDI, is different in certain aspects from that due to other conditions seen in cancer patients, such as vomiting and diarrhea. This prompted us to reflect on the need to grade polyuria, and how to grade it, and to consider a specific grading system for dehydration associated with CDI induced by ICI. Here we propose a new grading system for polyuria and dehydration, as critical symptoms of the CDI syndrome occurring in patients on ICI treatment, to obtain better management of both the adverse event and the triggering drugs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Barnabei, Strigari, Corsello, Paragliola, Iannantuono, Salvatori, Corsello and Torino.)

Nocturnal polyuria is the most frequent cause of nocturia, a common disease associated with a compromised quality of life and increased mortality. Its pathogenesis is complex, and the detailed underlying mechanism remains unknown. Herein, we report that concomitant intake of a high-salt diet and reduced nitric oxide (NO) production achieved through N ω -Nitro-L-arginine methyl ester hydrochloride (L-NAME) administration in mice resulted in nocturnal polyuria recapitulating the clinical features in humans. High salt intake under reduced NO production overactivated the angiotensin II-SPAK (STE20/SPS1-related proline-alanine-rich protein kinase)-NCC (sodium chloride co-transporter) pathway in the kidney, resulting in the insufficient excretion of sodium during the day and its excessive excretion at night. Excessive Na excretion at night in turn leads to nocturnal polyuria due to osmotic diuresis. Our study identified a central role for the intrarenal angiotensin II-SPAK-NCC pathway in the pathophysiology of nocturnal polyuria, highlighting its potential as a promising therapeutic target., (© 2022. The Author(s).)

Competing Interests: AUTHOR DISCLOSURE: Mss Mishra and McCormick and Dr Marks have disclosed no financial relationships relevant to this article. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.

Context: Salt and water homeostasis is regulated hormonally, so polyuria can result from endocrine disease directly or via secondary effects. These mechanisms are not consistently considered in primary care management of nocturia., Objective: To conduct a systematic review (SR) of nocturia in endocrine disease and reach expert consensus for primary care management., Evidence Acquisition: Four databases were searched from January 2000 to April 2020. A total of 4382 titles and abstracts were screened, 36 studies underwent full-text screening, and 14 studies were included in the analysis. Expert and public consensus was achieved using the nominal group technique (NGT)., Evidence Synthesis: Twelve studies focused on mechanisms of nocturia, while two evaluated treatment options; none of the studies took place in a primary care setting. NGT consensus identified key clinical evaluation themes, including the presence of thirst, a medical background of diabetes mellitus or insipidus, thyroid disease, oestrogen status, medications (fluid loss or xerostomia), and general examination including body mass index. Proposed investigations include a bladder diary, renal and thyroid function, calcium, and glycated haemoglobin. Morning urine osmolarity should be examined in the context of polyuria of >2.5 l/24 h persisting despite fluid advice, with urine concentration >600 mOsm/l after fluid restriction excluding diabetes insipidus. Treatment should involve education, including adjustment of lifestyle and medication where possible. Any underlying endocrine disorder should be managed according to local guidance. Referral to endocrinology is needed if there is hyperthyroidism, hyperparathyroidism, or morning urine osmolarity <600 mOsm/l after overnight fluid avoidance., Conclusions: Endocrine disease can result in nocturia via varied salt and water regulation pathways. The aim of management is to identify and treat causative factors, but secondary effects can restrict improvements in nocturia., Patient Summary: People with altered hormone function can suffer from severe sleep disturbance because of a need to pass urine caused by problems in controlling water and salt levels. An expert panel recommended the best ways to assess and treat these problems on the basis of the rather small amount of up-to-date published research available., (Copyright © 2021 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Nocturia is a prevalent condition and may result from nocturnal polyuria, whereby overnight urine production is excessive. Anecdotal cases of idiopathic nocturnal polyuria in which cerebrospinal fluid (CSF) disorders were identified suggest a potential mechanism. The skull constrains three circulatory systems: the CSF, interstitial fluid, and vascular supply. For each, fluid dynamics (pressure, volume, and flow) are closely regulated and adapt to changes such as recumbency and circadian variation. Pathologies disrupting this regulation, and thus impairing intracranial fluid dynamics, will place the brain environment at risk. Hence, compensatory responses are needed to maintain safe limits and prevent neurological deficits. We hypothesise that a change in the fluid dynamics for the intracranial CSF, interstitial, or vascular circulation means that positional or circadian changes during sleep trigger compensatory hormonal responses to protect the brain, but these also cause nocturnal polyuria. Natriuretic hormones are candidate mediators for protection against excess intracranial pressure or volume. PATIENT SUMMARY: A need to pass urine during the night, which is called nocturia, may be because of excessive overnight urine production. We propose that changes in fluid dynamics in the brain caused by lying down or daily body rhythms may trigger the release of hormones that could be a factor in nighttime urine production. This hypothesis should be explored in further investigations., (Copyright © 2022 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

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., Competing Interests: Declaration of Competing Interest MCC speaking honoraria from Thermo Fisher AG, the manufacturer of the Copeptin Assay. OG declares that she has no competing interest., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Rationale: Paraganglioma (PGL), an extra-adrenal pheochromocytoma, is a rare tumor, especially in children. While hypersecretion of catecholamines causes the classic triad of headaches, palpitations, and profuse sweating, prompt diagnosis is still challenging., Patient Concerns: For 7 months, an 8-year-old boy complained of polyuria and weight loss, followed by proteinuria and headache for 1 month prior to admission. He was admitted to our hospital due to an afebrile seizure., Diagnosis: His blood pressure remained markedly elevated even after cessation of the convulsion. Magnetic resonance imaging of the brain revealed posterior reversible encephalopathy syndrome. Abdominal computed tomography showed a mass lesion encasing the left renal artery, measuring 41 mm in length along its major axis. The plasma and urine levels of normetanephrine were elevated. Additionally, iodine-123-metaiodobenzylguanidine scintigraphy showed an abnormal uptake in the abdominal mass with no evidence of metastasis. Based on these findings, we tentatively diagnosed him with PGL., Intervention: Substantial alpha- and beta-blocking procedures were performed, followed by a tumor resection and an extended left nephrectomy on day 31 of hospitalization. Pathological findings confirmed the diagnosis of PGL., Outcome: The postoperative course was uneventful, and his blood pressure normalized without the use of antihypertensive agents. Genetic testing revealed a known SDHB germline mutation. The same mutation was also detected on his father and paternal grandfather without any history of hypertension or malignant tumor., Lesson: It remains challenging to diagnose pheochromocytoma/paraganglioma (PPGL) promptly because PPGL can present with a variety of symptoms. Preceding symptoms of the presented case might be caused by PGL. Although PPGL is a rare disease, especially in children, it should be considered in differential diagnosis when various unexplained symptoms persist., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Traumatic neuroendocrine dysfunction may present with diabetes insipidus (DI) or with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Both these pathologies involve a disturbance in the antidiuretic hormone (ADH) secretion, causing dysnatremias. Diagnosis of posttraumatic ADH dysfunction is hampered by technical difficulties in ADH assessment, and relies mostly on non-specific serum sodium, serum and urine osmolality and diuresis, often leading to misdiagnosis in the acute care setting. Research now focuses on the diagnostic role of copeptin, a peptide secreted together with ADH in an equimolar fashion, and which can be accurately evaluated. Recent studies identified cut-off values of 2.6 pmol/L for baseline copeptin and of 4.9 and 3.8 pmol/L for hypertonic saline infusion and arginine infusion stimulated copeptin, respectively, for the diagnosis of DI in patients with polyuria-polydipsia syndrome. Although SIADH is more difficult to be explored due to its heterogeneity, a ratio of copeptin to urinary sodium below 30 pmol/mmol identifies euvolemic hyponatremia. Exploring the role of copeptin assessment in patients with traumatic brain injury (TBI) in the acute phase may improve their diagnosis accuracy, management and outcome., (Copyright © 2021 Elsevier Ltd. All rights reserved.)