Arginine or Hypertonic Saline-Stimulated Copeptin to Diagnose AVP Deficiency.

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.).

Primary polydipsia: Update.

In primary polydipsia pathologically high levels of water intake physiologically lower arginine vasopressin (AVP) secretion, and in this way mirror the secondary polydipsia in diabetes insipidus in which pathologically low levels of AVP (or renal responsiveness to AVP) physiologically increase water intake. Primary polydipsia covers several disorders whose clinical features and significance, risk factors, pathophysiology and treatment are reviewed here. While groupings may appear somewhat arbitrary, they are associated with distinct alterations in physiologic parameters of water balance. The polydipsia is typically unrelated to homeostatic regulation of water intake, but instead reflects non-homeostatic influences. Recent technological advances, summarized here, have disentangled functional neurocircuits underlying both homeostatic and non-homeostatic physiologic influences, which provides an opportunity to better define the mechanisms of the disorders. We summarize this recent literature, highlighting hypothalamic circuitry that appears most clearly positioned to contribute to primary polydipsia. The life-threatening water imbalance in psychotic disorders is caused by an anterior hippocampal induced stress-diathesis that can be reproduced in animal models, and involves phylogenetically preserved pathways that appear likely to include one or more of these circuits. Ongoing translational neuroscience studies in these animal models may potentially localize reversible pathological changes which contribute to both the water imbalance and psychotic disorder.

[Deleterious Results of Safety Seeking Behaviours in Panic Disorder: Polydipsia and Diabetes Mellitus Type 2]. / Panik Bozuklugunda Güvenlik Saglama Davranislarinin Medikal Sonuçlari: Polidipsi ve Tip 2 Diabetes Mellitus.

Panic disorder is an anxiety disorder that involves recurrent panic attacks, which emerge when a harmless stimulus is interpreted as "catastrophic". In an attempt to avoid the panic attack or prevent confrontation, the patient exhibits a dysfunctional attitude and behavior, such as evasion and safety-seeking behavior (SSB). Dysfunctional behavior leads to an increase in the recurrence of panic attacks and affects the patient's life in a negative way. According to the cognitive behavioral therapy model, SSB contributes to the continuation of unrealistic beliefs (e.g. physical experiences) regarding and prevents the patient from grasping new information that may potentially contradict the unrealistic cognitions. In this paper, we present a case with a primary diagnosis of panic disorder. Interestingly, this patient developed diabetes mellitus (DM) type 2 and psychogenic polydipsia (PPD) as a consequence of his SSB. PPD is a common occurrence in patients with psychiatric disorders, especially in schizophrenia. Up to now, no case of a panic disorder with either DM or PPD has been reported in the literature. While it is accepted that major depression poses a risk for DM type 2, panic disorder may also increase this risk. Treatment of the panic disorder with cognitive behavioral therapy (CBT) resulted in improvement of PPD and DM type 2. In conclusion, the role of SSB in medical disorders accompanied by psychiatric disorders should be kept in mind when treating these patients.

Effects of diet quality on vulnerability to mild subchronic social defeat stress in mice.

OBJECTIVES: The chronic social defeat stress (CSDS) mouse model is a potentially useful system for understanding stress responses to social environments. We previously developed a mouse model of subchronic and mild social defeat stress (sCSDS) that exhibits increased body weight gain and food intake following polydipsia-like features. sCSDS mice also show avoidance behavior in a social interaction test. In this study, we examined the effects of diet quality on susceptibility to sCSDS by feeding these mice semi- and non-purified diets. METHODS: Male C57BL/6J (B6; n = 82) mice were exposed to sCSDS using male ICR mice. The B6 mice were divided into four test groups: semi-purified pellet diet + sCSDS, non-purified pellet diet + sCSDS, semi-purified diet + control (no sCSDS), and non-purified diet + control. RESULTS: Although increased body weight, and food and water intake following sCSDS exposure were consistently observed in the groups that were fed semi- and non-purified diets, social avoidance behavior was influenced by food type (i.e., sCSDS mice fed semi-purified diet showed the greatest social avoidance behavior). In addition, the rates of stress susceptibility were estimated at 73.9 and 34.8% in sCSDS mice fed semi-purified and non-purified diets, respectively (P < 0.05). For comparison, the susceptible-like phenotype rates were estimated at 12.5 and 8.3% in healthy control mice fed semi-purified and non-purified diets, respectively. DISCUSSION: These results suggest that diet quality affects the vulnerability of mice to social defeat stress.

Recurrent rhabdomyolysis secondary to hyponatremia in a patient with primary psychogenic polydipsia.

Rhabdomyolysis is characterized by the destruction of skeletal muscle tissue, and its main causes are trauma, toxic substances and electrolyte disturbances. Among the latter is hyponatremia-induced rhabdomyolysis, a rare condition that occurs mainly in patients with psychogenic polydipsia. Psycogenic polydipsia mostly affects patients with schizophrenia, coursing with hyponatremia in almost 25% of the cases. It is also in this context that rhabdomyolysis secondary to hyponatremia occurs most often. In this article, the case of a 49-year-old male with a history of schizophrenia, medicated with clozapine, and brought to the emergency room in a state of coma and seizures is described. Severe hypoosmolar hyponatremia with cerebral edema was found on a computed tomography examination, and a subsequent diagnosis of hyponatremia secondary to psychogenic polydipsia was made. Hyponatremia correction therapy was started, and the patient was admitted to the intensive care unit. After the hyponatremia correction, the patient presented with analytical worsening, showing marked rhabdomyolysis with a creatine phosphokinase level of 44.058 UI/L on day 3 of hospitalization. The condition showed a subsequent progressive improvement with therapy, with no occurrence of kidney damage. This case stresses the need for monitoring rhabdomyolysis markers in severe hyponatremia, illustrating the condition of rhabdomyolysis secondary to hyponatremia induced by psychogenic polydipsia, which should be considered in patients undergoing treatment with neuroleptics.

Rabdomiólise recorrente secundária à hiponatremia em doente com polidipsia psicogênica primária / Recurrent rhabdomyolysis secondary to hyponatremia in a patient with primary psychogenic polydipsia

A rabdomiólise é caracterizada por destruição de tecido muscular esquelético, sendo as suas principais causas o trauma, os tóxicos e os distúrbios hidroeletrolíticos. Entre esses últimos, inclui-se a rabdomiólise induzida por hiponatremia, uma situação rara, que ocorre principalmente em doentes com polidipsia psicogênica. Esta acomete maioritariamente doentes com esquizofrenia, cursando com hiponatremia em quase 25% dos casos. É também nesse contexto que a rabdomiólise secundária a hiponatremia ocorre mais frequentemente. Neste artigo, descreveu-se o caso de um homem de 49 anos, com antecedentes de esquizofrenia, medicado com clozapina, trazido ao serviço de urgência por quadro de coma e convulsões. Foi objetivada hiponatremia hiposmolar grave, com edema cerebral em tomografia computorizada, sendo feito posteriormente o diagnóstico de hiponatremia secundária à polidipsia psicogênica. Foi iniciada terapêutica de correção de hiponatremia e internado em unidade de terapia intensiva. Feita correção de hiponatremia, contudo apresentou analiticamente marcada rabdomiólise, de agravamento crescente, com creatinofosfoquinase de 44.058UI/L no 3º dia de internação. Houve posterior redução progressiva com a terapêutica, sem ocorrência de lesão renal. Este caso alerta para a necessidade de monitorização dos marcadores de rabdomiólise na hiponatremia grave, ilustrando um quadro de rabdomiólise secundária à hiponatremia induzida por polidipsia psicogênica, situação a considerar em doentes sob terapêutica com neurolépticos.

Rhabdomyolysis is characterized by the destruction of skeletal muscle tissue, and its main causes are trauma, toxic substances and electrolyte disturbances. Among the latter is hyponatremia-induced rhabdomyolysis, a rare condition that occurs mainly in patients with psychogenic polydipsia. Psycogenic polydipsia mostly affects patients with schizophrenia, coursing with hyponatremia in almost 25% of the cases. It is also in this context that rhabdomyolysis secondary to hyponatremia occurs most often. In this article, the case of a 49-year-old male with a history of schizophrenia, medicated with clozapine, and brought to the emergency room in a state of coma and seizures is described. Severe hypoosmolar hyponatremia with cerebral edema was found on a computed tomography examination, and a subsequent diagnosis of hyponatremia secondary to psychogenic polydipsia was made. Hyponatremia correction therapy was started, and the patient was admitted to the intensive care unit. After the hyponatremia correction, the patient presented with analytical worsening, showing marked rhabdomyolysis with a creatine phosphokinase level of 44.058UI/L on day 3 of hospitalization. The condition showed a subsequent progressive improvement with therapy, with no occurrence of kidney damage. This case stresses the need for monitoring rhabdomyolysis markers in severe hyponatremia, illustrating the condition of rhabdomyolysis secondary to hyponatremia induced by psychogenic polydipsia, which should be considered in patients undergoing treatment with neuroleptics.

[Risperidone treatment for polydipsia and severe hyponatremia in a schizophrenic patient]. / Traitement par rispéridone d'une polydipsie avec hyponatrémie sévère chez un patient schizophrène.

We report the case of a patient with undifferentiated schizophrenia since 10 years, who presented a polydipsia and severe hyponatremia. This patient responded well to a combination of an atypical antipsychotic (risperidone 4 mg/day) and a behavioral approach based on fluid restriction.

Diabetes insipidus.

Diabetes insipidus (DI) is characterized by hypotonic polyuria greater than 3 liters/24 hours in adults and persisting even during water deprivation. It is mostly due to a defect in arginin-vasopressin (AVP) synthesis (central DI); other causes are: AVP resistance (nephrogenic DI), abnormal thirst regulation (primary polydipsia) or early destruction of AVP by placental enzymes (gestational DI). A thorough medical history is warranted to investigate nocturnal persistence of polyuria (night waking being a good sign of its organic nature) to specify the onset and duration of the trouble, the medication use and the potential hereditary nature of the disorder. The next step is based on weight and blood pressure measurements and especially the quantification of beverages and diuresis over a 24-hour cycle. Assessment of signs of dehydration, bladder distention, pituitary hormone hyper- or hyposecretion, tumor chiasmatic syndrome, granulomatosis and cancer is required. The diagnosis is based on biological assessment, pituitary magnetic resonance imaging (MRI) and results of a desmopressin test. In severe forms of DI, urine osmolality remains below 250 mOsmol/kg and serum sodium greater than 145 mmol/L. In partial forms of DI (urine osmolality between 250 and 750), the water deprivation test demonstrating the incapacity to obtain a maximal urine concentration is valuable, together with vasopressin or copeptin measurement. The pituitary MRI is done to investigate the lack of spontaneous hyperintensity signal in the posterior pituitary, which marks the absence of AVP and supports the diagnosis of central DI rather than primary polydipsia (although not absolute); it can also recognize lesions of the pituitary gland or pituitary stalk. Acquired central DI of sudden onset should suggest a craniopharyngioma or germinoma if it occurs before the age of 30 years, and metastasis after the age of 50 years. Fifteen to 20% of head trauma lead to hypopituitarism, including DI in 2% of cases. Transient or permanent DI is present in 8-9% of endoscopic transphenoidal surgeries. Current advances in DI concern the etiological work-up, with in particular the identification of IgG4-related hypophysitis or many genetic abnormalities, opening the field of targeted therapies in the years to come.

Primary polydipsia: a case report.

Primary polydipsia (PP) is etiologically associated with physical factors and psychiatric disorders ("psychogenic polydipsia"). We present the case of a 28-year-old man with severe symptoms of polydipsia and polyuria. After a comprehensive physical assessment, the only finding was a lesion suggestive of pituitary microadenoma in the magnetic resonance imaging (MRI) scan of the brain. A thorough clinical and diagnostic assessment and the administration of a wide range of psychometric tools revealed no major psychiatric disorder apart from chronic anxiety and mild depressive symptoms. Our patient's PP symptoms might be associated with a dysfunction of the thirst center, which is located closely to the neuroanatomical lesion found in the MRI scan. Given that the underlying pathophysiology of PP remains, to a large extent, unclear, we emphasize on the difficulties to distinguish between PP's subtypes.

Risperidone treatment for polydipsia and hyponatremia in schizophrenia: a case report.

Psychogenic polydipsia with associated hyponatremia is a potentially fatal condition observed in patients with chronic psychiatric illness, especially schizophrenia. Recognition and management of this condition are difficult, as patients are uncooperative and secretive about their water intake, but are important in terms of the associated complications. Different strategies, including involuntary fluid restriction and use of various pharmacological agents, such as demeclocycline, propranolol, captopril, and naloxone, have been used for the treatment of this condition with inconsistent results. Antipsychotics have also been used in the treatment of polydipsia; however, their role is not clear as there are reports of antipsychotics both improving and causing polydipsia. Typical antipsychotics have been associated with exacerbation of polydipsia, whereas clozapine has been associated with its improvement. The efficacy of risperidone in the treatment of this condition is controversial, as negative results have been reported. Herein we present a schizophrenia case with polydipsia and hyponatremia that was successfully treated with risperidone.