Dipsogenic diabetes insipidus: Report of a novel treatment strategy and literature review

Dipsogenic diabetes insipidus is a syndrome of disordered thirst, in patients without psychiatric disease, which may be confused with partial central diabetes insipidus. Distinguishing these entities involves monitored water testing. Therapy with antidiuretic hormone in patients with dipsogenic diabetes insipidus is thought to be contraindicated for fear of inducing water intoxication. We report a case of a 26-year-old woman without psychiatric illness referred for longstanding polyuria and polydipsia. Otherwise healthy, she complained of near-constant thirst and frequent urination, causing severe disruption of her personal and professional life. She had been consistently eunatremic and polyuric, with low urine osmolality. Results of extensive water testing revealed intact urinary concentrating and diluting capacity, physiologic though blunted antidiuretic hormone (ADH) release, and an abnormally low thirst threshold, consistent with the diagnosis of dipsogenic diabetes insipidus. To control her polyuria we initiated treatment with intermittent, low-dose, intranasal desmopressin and strict water restriction during drug dosing. In follow-up she reported excellent control of polyuria and significant functional improvement. The reviewed literature demonstrates a limited number of reports about dipsogenic diabetes insipidus, and no prior report of a similar treatment strategy. Dipsogenic diabetes insipidus is an uncommonly (and not universally) recognized disorder, requiring monitored testing in order to distinguish it from incomplete forms of central diabetes insipidus. Though therapy with desmopressin cannot be recommended based on the results of a single case, the outcome presented here is intriguing and suggests that larger studies in such patients is warranted to assess the broader application of such an intervention.