title: Changes in stone composition according to age and gender in Tunisian children.
abstract: OBJECTIVE
  Studies evaluating the influence of age and gender on the distribution of the various types of pediatric urinary calculi are scarce. The aim of this study was to highlight the modification of epidemiological characteristics of this pathology according to patients' sex and age.
  
  
  METHODS
  A total of 205 calculi (from 122 boys and 83 girls) were analyzed by infrared spectroscopy between 1993 and 2007; 54.6% of the patients were under 5 years.
  
  
  RESULTS
  Calcium oxalate was the predominant constituent in 54.7% of stones, followed by calcium phosphate and purines (14.6% each). We found a predominance of calcium oxalate in females (59.1% vs 50.8%), and a male preponderance for struvite stones (12.3% vs 1.2%). There was an increasing prevalence of calcium oxalate stones with age in both genders (42.9% in infants vs 59.3% in older children). Purine stones were predominant in 20% of cases, but prevalence decreased with age (28.6% in infants vs 18.5% in older children).
  
  
  CONCLUSIONS
  The increase in calcium oxalate stones in school-age children and the decrease in stones containing purines confirm a change in the etiology of urolithiasis according to age.
authors.affiliation: Department of Biochemistry and Toxicology, Fattouma Bourguiba Hospital, Monastir 5000, Tunisia. akram_alaya@yahoo.co.uk
authors.forename: A
authors.initials: A
authors.lastname: Alaya
authors.forename: A
authors.initials: A
authors.lastname: Nouri
authors.forename: M F
authors.initials: MF
authors.lastname: Najjar
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012737:Sex Factors; D014416:Tunisia; D014545:Urinary Calculi / Q000737:chemistry* / Q000453:epidemiology*