Unusual Presentation of Arginine-Vasopressin Deficiency: Long Story Short, Decades of Polyuria without Proper Diagnosis

Introduction: Arginine Vasopressin Deficiency (AVP-D), formerly Diabetes Insipidus, is a rare disorder causing polyuria and free water loss. Typical findings include hypernatremia and low urine osmolality. A positive response to desmopressin (DDAVP) indicates central deficiency. This case underscores the importance of thorough history and high suspicion for AVP-D despite normal electrolytes to ensure prompt diagnosis and improvement in quality of life. Case Description: 33-year-old female with no past medical history who presented to our nephrology clinic by referral from PCP. Chief complaint was decades of polyuria. Since the age of 7, she remembers having trouble with nocturia. She recalls multiple sleepovers at 11 years of age. She had to sneak out multiple times at night to urinate to a point she needed to use ‘pull ups” at sleepovers. In her words: “ every road trip We had I remember how my family would say we would have gotten there much faster if they didnt have to stop multiple times to pee”. To a point she would just use a “pull up” to “get there faster”. In school, her teachers would not let her go to the bathroom as often as she needed it, they blamed “you are just going to fix your make-up”. At work during her first job, but being so embarrassed of how often she needed to use the bathroom that she went to other floors in the building so her co-workers would not notice. Her first medical appointment at 7yrs old had cystoscopy done which was normal, few years later was reevaluated and was treated for “overactive bladder”. During her pregnancy her polyuria was blamed on bladder pressure from the baby and was complicated by polyhydramnios and post-partum hemorrhage. At 30 yrs of age she presented to our nephrology clinic. 24 hour urine with self imposed fluid restriction revealed 5.7L of urine. Brain MRI was normal, genetic testing was unrevealing, no history of head trauma or surgery. Patient was diagnosed with idiopathic AVP-D and started on DDAVP and since then her life changed forever. Discussion: This case emphasizes the need to consider AVP-D in chronic polyuria cases, even without typical hypernatremia. Delayed diagnosis of AVP-D led to decades of distress for this patient. Early recognition and treatment with DDAVP drastically improved her quality of life, underscoring the necessity for vigilance in cases like this.