P-492: Clinical case of a patient with type 1 diabetes and arginine vasopressin deficiency, withouth Wolfram syndrome

Introduction

The coexistence of type 1 diabetes mellitus (T1D) and arginine vasopressin deficiency (AVD) is rare und usually associated with Wolfram Syndrome (WS).

Objectives

To describe the case of a patient with T1D who developed arginine vasopressin deficiency without WS

Methods

A 16-year-old male with T1D confirmed by two positive autoantibodies, treated with multiple daily insulin injections. Past history included refractory epilepsy surgically treated in childhood, polymicrogyria, cerebral palsy, and left brachio-crural hemiparesis.

2 weeks before admission, he developed vomiting and gastrointestinal discomfort, followed by persistent polyuria and polydipsia with usual glucose levels. Labs showed elevated plasma osmolality (300 mOsm/kg) with low urine osmolality (107 mOsm/kg), normal electrolytes, and HbA1c of 7.4%. He was hospitalized for evaluation. Brain CT showed only known postsurgical changes. A water deprivation test revealed rising plasma osmolality (310 mOsm/kg), serum sodium 149 mEq/L, and urine osmolality 560 mOsm/kg. After IV desmopressin, serum sodium normalized and urine osmolality increased to 673 mOsm/kg, consistent with partial AVD.

Oral desmopressin was initiated with a good response. Pituitary MRI showed absence of the posterior pituitary bright spot and mild pituitary stalk thickening, without nodules or optic pathway involvement. Additional studies (abdominal ultrasound, whole-body MRI, tumor markers, immunologic tests, lumbar puncture) were normal. He was evaluated by oncologist, ophthalmologist, oncologist, genetics specialist with no syndromic features.

Results

On follow-up, he remained asymptomatic from AVD, with stable T1D control. MRI at 3 months showed resolution of pituitary stalk thickening.

Conclusions

This case underscores the possibility of having double diabetes in a patient without WS. Structural neurological disease may complicate diagnosis, requiring multidisciplinary and imaging follow-up. Favorable evolution highlights the importance of systematic and longitudinal evaluation.