title: Urinary stone composition in Israel: current status and variation with age and sex--a bicenter study.
abstract: OBJECTIVE
  The epidemiologic data regarding stone composition in Israel are based on anachronistic methods of stone analysis. Historically, Israel was noted for an unusually high percentage of uric acid stones. The aim of the study was to describe the current stone composition distribution in Israel, using modern techniques of urinary stone analysis. Age and sex correlations were investigated.
  
  
  METHODS
  In a bicenter study, using infrared spectroscopy and X-ray diffraction, stones from five hundred and thirty eight (538) patients were analyzed and demographic data recorded.
  
  
  RESULTS
  The study cohort included 401 men (74.5%) and 137 women (25.5%) with a male to female ratio of 2.9:1 and a median age of 48 years (range 2-85 years). While calcium oxalate monohydrate was the predominant component in both sexes, it was lower in female patients (77.3% vs 65%). The rate of infection stones (struvite+carbonate apatite) was significantly higher in women (35.7% vs 10.2%). Uric acid stones were found in only 14.5% of the patients and increased with age. Conversely, the rate of calcium oxalate dihydrate decreased with age.
  
  
  CONCLUSIONS
  Modern techniques of urinary stone analysis showed that the most frequent stone component in Israel is calcium oxalate monohydrate. In contrast to earlier reports and in accordance with reports from other countries, the overall frequency of uric acid is 14.5%. With age, the frequency of uric acid increases reaching 21% in persons >60 years old. A significant sex difference was noted in the distribution of calcium oxalate stones and infection stones. The classic 3:1 ratio was maintained, however.
authors.affiliation: 1 Rabin Medical Center, Petach Tikva and Sakler Tel Aviv University Sackler School of Medicine , Petah Tikva, Israel .
authors.forename: Kalba D
authors.initials: KD
authors.lastname: Usman
authors.forename: Shay
authors.initials: S
authors.lastname: Golan
authors.forename: Tamer
authors.initials: T
authors.lastname: Abdin
authors.forename: Pinhas M
authors.initials: PM
authors.lastname: Livne
authors.forename: Dov
authors.initials: D
authors.lastname: Pode
authors.forename: Mordechai
authors.initials: M
authors.lastname: Duvdevani
authors.forename: David
authors.initials: D
authors.lastname: Lifshitz
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002129:Calcium Oxalate / Q000032:analysis* / Q000652:urine; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012737:Sex Factors; D013055:Spectrophotometry, Infrared; D014527:Uric Acid / Q000032:analysis* / Q000652:urine; D014545:Urinary Calculi / Q000737:chemistry* / Q000453:epidemiology / Q000652:urine; D055815:Young Adult
chemical_list: D002129:Calcium Oxalate; D014527:Uric Acid