Medline ® Abstract for Reference 6
of 'Treatment of nephrogenic diabetes insipidus'
Bladder function impairment in aquaporin-2 defective nephrogenic diabetes insipidus.
Shalev H, Romanovsky I, Knoers NV, Lupa S, Landau D
Nephrol Dial Transplant. 2004;19(3):608.
BACKGROUND: The aim of this study was to describe the urological complications associated with nephrogenic diabetes insipidus (NDI) due to a mutation in aquaporin-2 (AQP2), a collecting-duct protein activated by ADH signalling.
METHODS: We provide a case series description of a group of seven patients with autosomal recessive NDI due to AQP2 gene mutation, receiving routine medical management since diagnosis in the first months of life.
RESULTS: Mean urine osmolarity at diagnosis and last follow-up was 89+/-25 and 83+/-18 mosm/l, respectively. Hydroureteronephrosis was observed in all children, beginning at age 3 years. Two children have daytime enuresis at ages 7 and 10 years and all children older than 6 years continue to have nocturnal enuresis. Markedly enlarged bladders were observed as early as age 4 years in all patients. Trabeculated bladder walls were found in three children. Urodynamic studies performed in two daytime incontinent children revealed a hypotonic-large-capacity type of neurogenic bladder. No impairment in kidney function is currently observed.
CONCLUSIONS: The severe renal concentrating defect in this type of NDI is associated with the development of hydroureteronephrosis followed by bladder enlargement and dysfunction. Careful follow-up is needed in order to assure that no bladder outlet obstruction and/or renal insufficiency develop.
Department of Pediatrics, Soroka University Medical Center, Ben Gurion University of the Negev, Beer Sheva, Israel.