title: Hypercalciuria is related to osmolar excretion in children with nocturnal enuresis.
abstract: OBJECTIVE
  We evaluated the incidence of hypercalciuria, defined as urinary calcium-to-creatinine ratio greater than 0.21 mg/mg, in children with nocturnal enuresis, and the association with concurrent values of diuresis and osmolar excretion.
  
  
  METHODS
  A total of 550 children admitted to a tertiary university center were included in the study. A 24-hour urine collection was performed in 8 sampling periods for measurement of calcium excretion, osmolality and diuresis.
  
  
  RESULTS
  Of the children with nocturnal enuresis 12% had 24-hour hypercalciuria. Up to 29% of the timed urine samples exhibited hypercalciuria. There was a significant correlation between calcium excretion and nocturnal diuresis volume (polyuria), low urinary osmolality, and increased sodium and osmolar excretion of nighttime urine samples (all p <0.001).
  
  
  CONCLUSIONS
  Patients referred to a tertiary enuresis center have a high incidence of hypercalciuria. However, the significant correlation between hypercalciuria and osmolar excretion and diuresis suggests that it is a comorbid factor rather than a primary pathogenic factor. As such, we cannot confirm the data from Italian studies relating nocturnal enuresis to primary hypercalciuria, and suggest instead an association with nutritional intake.
authors.affiliation: Department of Pediatric Nephrology, University Hospital Ghent, Ghent, Belgium. ann.raes@ugent.be
authors.forename: A
authors.initials: A
authors.lastname: Raes
authors.forename: L
authors.initials: L
authors.lastname: Dossche
authors.forename: N
authors.initials: N
authors.lastname: Hertegonne
authors.forename: L
authors.initials: L
authors.lastname: Nuytemans
authors.forename: P
authors.initials: P
authors.lastname: Hoebeke
authors.forename: E
authors.initials: E
authors.lastname: Van Laecke
authors.forename: R
authors.initials: R
authors.lastname: Donckerwolcke
authors.forename: J Vande
authors.initials: JV
authors.lastname: Walle
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D053565:Hypercalciuria / Q000453:epidemiology / Q000209:etiology*; D015994:Incidence; D008297:Male; D053206:Nocturnal Enuresis / Q000150:complications* / Q000378:metabolism*; D009994:Osmolar Concentration