7610 Retrospective Case-Control Study Identifying Clinical Characteristics of Patients Who Recover from Chronic Arginine-Vasopressin-Deficiency

Abstract Disclosure: C.O. Sailer: None. A. Aulinas Maso: None. F. Galbiati: None. M. Muhammed: None. R. Boutin: None. J. Bourassa: None. C. Atila: None. J. Crowley: None. A. Dayno: None. H. Pearlstein: None. L. Nachtigall: None. K.K. Miller: None. N.A. Tritos: None. U.B. Kaiser: None. J.G. Verbalis: None. L. Dichtel: Consulting Fee; Self; Lumos Pharma. Research Investigator; Self; Pfizer, Inc., Spectrum Ltd, Novartis Pharmaceuticals. E.A. Lawson: Research Investigator; Self; Tonix Pharmaceuticals. Background: Arginine-vasopressin (AVP) deficiency (AVP-D), formerly known as central diabetes insipidus, is characterized by insufficient AVP secretion leading to polyuria/polydipsia and treated with desmopressin. AVP-D is most often acquired secondary to neurohypophyseal or hypothalamic damage, e.g., from tumor or surgical complication, and can be transient or chronic. While cases of spontaneous recovery from chronic AVP-D have been described, no study has compared clinical characteristics of those who recover to those who do not. Understanding these differences may elucidate mechanisms of AVP-D recovery and help identify individuals who are at risk of developing complications of overtreatment in the setting of recovery. Methods: In this retrospective case-control study (1:2 matched for sex and desmopressin treatment duration), we investigated clinical characteristics of adults with chronic AVP-D with (n=18) vs without (n=36) recovery, defined as discontinuation of desmopressin after at least 6 months of initial treatment without recurrence of sustained polyuria/polydipsia. Diagnosis of AVP-D was confirmed by chart review by board certified endocrinologists. Clinical characteristics were assessed at diagnosis of AVP-D, recovery from AVP-D, and most recent visit. Group comparisons were done using t-test or X2-test. Results: Most common etiologies of pituitary/hypothalamic disease were craniopharyngioma (35%), non-functioning pituitary adenoma (15%), and germinoma (15%). AVP-D mainly developed after surgery (63%) or was tumor-related (32%). At diagnosis, those who ultimately recovered from AVP-D (vs those who did not) were older (46 vs 33 years, p=0.007); had lower random sodium levels (144 vs 148 mmol/l, p=0.015); received lower desmopressin doses (100 vs 200 ug/d, p=0.012); and trended toward lower polydipsia (5.9 vs 9.5 L/d, p=0.09). At recovery, mean duration of AVP-D was 8.5±8.3 years. Initial signs of recovery were reduced desmopressin dose (67%), reduced nocturia frequency and/or volume (67%), reduced urine output frequency and/or volume (50%), reduced thirst perception (22%), and development of hyponatremia (17%). At most recent visit, those who recovered (vs those who did not) were less likely to have gonadotropin deficiency (56% vs 89%, p=0.015). Conclusion: We have identified clinical differences in a cohort of adults with chronic AVP-D who recovered compared to those who did not, supporting the notion that chronic AVP-D may not always be permanent and improving our understanding of disease course. Recovery from AVP-D seems to be more common than previously considered, and patients, especially those with milder initial AVP-D, should be monitored regularly and reassessed for continued replacement need to prevent complications such as hyponatremia. Presentation: 6/2/2024