Management of Diabetes Insipidus in Adults

Clinical Presentation

Adults with diabetes insipidus produce massive individual void volumes, causing bladder dysfunction in 46% of patients due to chronic exposure to these overwhelming volumes, including incomplete voiding and urinary tract dilatation 1
The volumes are sufficient to cause "bed flooding" - a term used to convey that single nocturnal voids exceed the capacity of standard containment measures 1, 2
Children require "double nappies" (double-layered diapering) because single void volumes overflow the inner diaper, necessitating an outer adult-sized diaper to absorb the overflow 1
Parents must change diapers multiple times during the night due to the massive single-void volumes produced 3

Urine osmolality is maximally dilute, meaning the kidneys cannot concentrate urine, leading to rapid accumulation of large volumes 1, 2
Bladder continence is delayed until 8-11 years of age specifically because the nervous system's normal bladder control mechanisms cannot manage the overwhelming per-void volumes 1, 2

Urological complications occur in 46% of patients, with nocturnal enuresis and incomplete voiding being most frequent due to the sheer volume burden on the bladder 4
Urinary tract dilatation ("flow uropathy") develops from chronic exposure to these large volumes, affecting the upper urinary tract and causing bladder dysfunction 3, 4
Surveillance imaging every 2 years is recommended to monitor for hydronephrosis, bladder wall hypertrophy, and post-void residual urine caused by the volume burden 3

Combination therapy with thiazide diuretics and prostaglandin synthesis inhibitors can reduce total diuresis by up to 50%, which proportionally reduces per-void volumes 1, 5
Dietary modifications (low salt, low protein) reduce renal osmotic load, thereby decreasing both total urine volume and individual void volumes 3, 4