title: The circadian defect in plasma vasopressin and urine output is related to desmopressin response and enuresis status in children with nocturnal enuresis.
abstract: OBJECTIVE
  We correlated the circadian rhythm of plasma arginine vasopressin and urine output profile to desmopressin response, presence or absence of an enuretic episode, and age and gender in children with nocturnal enuresis.
  
  
  METHODS
  We studied 125 children 6 to 17 years old (mean age 10.4 +/- 3 years) with monosymptomatic nocturnal enuresis. Circadian inpatient studies were performed with standardized fluid intake, 7 blood sampling times and 6 urine collection periods. Subsequently, nocturnal urine volume was measured at home by diaper weighing for 4 weeks in 78 patients (2 weeks without treatment followed by 2 weeks of dose titration from 20 to 40 mug desmopressin at bedtime).
  
  
  RESULTS
  The circadian studies showed that all groups of patients had an attenuated arginine vasopressin rhythm, females generally had lower circadian plasma arginine vasopressin levels than males, desmopressin responders with enuresis during the study night had the largest nocturnal urine excretion rate and most pronounced arginine vasopressin deficiency, and nocturnal urine output was significantly greater during nights with enuresis than nights without. Part of this polyuria was caused by increased sodium excretion. The home recordings confirmed higher nocturnal urine volume on enuresis nights.
  
  
  CONCLUSIONS
  In addition to providing further pathophysiological support for the role of a nocturnal arginine vasopressin deficiency behind nocturnal polyuria in a subset of patients with enuresis, the results emphasize the clinical value of estimating nocturnal urine production on wet nights before selecting a therapeutic modality.
authors.affiliation: Department of Pediatrics, Center for Child Incontinence, Aarhus University Hospital, Skejby, Aarhus, Denmark. rittig@ki.au.dk
authors.forename: Søren
authors.initials: S
authors.lastname: Rittig
authors.forename: Henriette Lassen
authors.initials: HL
authors.lastname: Schaumburg
authors.forename: Charlotte
authors.initials: C
authors.lastname: Siggaard
authors.forename: Frank
authors.initials: F
authors.lastname: Schmidt
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Djurhuus
mesh_terms: D000293:Adolescent; D050034:Antidiuretic Agents / Q000494:pharmacology*; D002648:Child; D002940:Circadian Rhythm; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D053206:Nocturnal Enuresis / Q000097:blood*; D014556:Urine; D014667:Vasopressins / Q000097:blood*
chemical_list: D050034:Antidiuretic Agents; D014667:Vasopressins; D003894:Deamino Arginine Vasopressin