title: Risk factors in urinary calcium oxalate stone formation and their relation to urinary calcium oxalate supersaturation.
abstract: BACKGROUND
  We studied the effect of potential risk factors of urinary calcium oxalate saturation on calcium oxalate stone formation.
  
  
  METHODS
  Using the Equil2 program, the DG values of calcium oxalate in 390 clinical urine specimens were estimated in 5 healthy male individuals with and without citrate therapy.
  
  
  RESULTS
  Critical calcium-oxalate supersaturation (DG value, > 2.8) was noted in 15 out of 390 urine specimens. Of the 15, 14 late night or morning specimens had critical calcium oxalate supersaturation, while only 1 afternoon specimen was supersaturated. Critical calcium oxalate supersaturation was often associated with hyperoxaluria and hypercalciuria, while undersaturation was often associated with hypomagnesiuria, a high Ca/Mg ratio, and hypocitraturia.
  
  
  CONCLUSIONS
  Hypomagnesiuria, hypocitraturia, and a high Ca/Mg ratio appear to be poor indicators of calcium-oxalate supersaturation, and it is hard to predict the level of calcium-oxalate saturation using single parameters.
authors.affiliation: Department of Urology, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ogawa
authors.forename: T
authors.initials: T
authors.lastname: Hatano
mesh_terms: D000328:Adult; D002129:Calcium Oxalate / Q000652:urine*; D002940:Circadian Rhythm; D002951:Citrates / Q000652:urine; D006801:Humans; D008274:Magnesium / Q000652:urine; D008297:Male; D012016:Reference Values; D012307:Risk Factors; D014545:Urinary Calculi / Q000209:etiology* / Q000652:urine
chemical_list: D002951:Citrates; D002129:Calcium Oxalate; D008274:Magnesium