Endocrine Abstracts

JOINT2340

Introduction: Polyuria-polydipsia syndrome is a rare medical condition, characterized by excessive urine output (≥3 L/24 hour) with continuous ingestion of fluids. This syndrome can be due to defects in antidiuretic hormone production, secretion or renal response or from primary excessive fluid intake. Correct diagnosis is crucial, as treatment protocols differ significantly. A misdiagnosis may result in severe, life-threatening outcomes. However, the challenge lies in reaching an accurate diagnosis due to a significant overlap among the different forms of Diabetes insipidus (DI) and primary polydipsia, particularly in developing countries like Georgia, where access to diagnostic tests is limited.

Case presentation: We present an 18-year-old girl with history of polydipsia, polyuria, oligomenorrhea and binge eating. On physical examination, her vitals were within normal limits and body mass index was 28.8 kg/m². Additional evaluation was performed, including a negative urinary pregnancy test and the exclusion of urinary tract infection. Patient denied any history of head trauma. A 24-hour urine collection test was conducted, which confirmed polyuria (8.5 L/24 h). Additional testing excluded osmotic diuresis; electrolyte levels were within normal ranges, sodium being high-normal. Osmolality measurements revealed low urine osmolality-271mOsm/kg, while serum osmolality remained within normal limits. Based on the laboratory results neither primary polydipsia nor DI could be confirmed or excluded. The patient was advised to undergo further evaluation with water deprivation test. However, this test could not be fully performed in Georgia, as osmolality measurements are sent abroad, requiring days for results. Consequently, the second phase of the test, the desmopressin challenge, could not be conducted locally. Given the patient’s clinical history and laboratory findings, it was decided to proceed with partial water deprivation test, focusing on the dehydration phase, with subsequent assessment of osmolality and copeptin levels. Additionally, psychiatric evaluation was recommended to further guide the diagnostic process. Following the partial water deprivation test, urine osmolality remained low, indicating the need for desmopressin phase. However, due to financial constraints, the patient was unable to travel abroad for further testing. As a result, psychiatric and psychological treatment were initiated with close supervision. Within a few weeks, the patient reported a noticeable reduction in water intake and an overall improvement in her symptoms.

Conclusions: This case highlights the complexities of diagnosing polyuria-polydipsia syndrome, especially in developing nations. Water deprivation test remains gold standard, with desmopressin phase providing essential diagnostic value. However, limitations in diagnostic resources in Georgia create substantial obstacles. Though the water deprivation test remained incomplete, the patient’s gradual improvement following psychological intervention supports the diagnosis of psychogenic polydipsia. Main emphasis of this case is the relevance of a team-based approach in managing complex endocrine disorders, especially in countries where diagnostic tools are limited.