title: Correspondence between stone composition and urine supersaturation in nephrolithiasis.
abstract: Supersaturation (SS) with respect to calcium oxalate monohydrate (COM), brushite (Br) and uric acid (UA), obtained in three 24-hour pretreatment urine samples from patients with stone disease were compared to the mineral composition of stones passed by the same patients to determine whether sparse urine SS measurements accurately reflect the long-term average SS values in the kidney and final urine. Among males and females elevation of SS above same sex normals corresponded to composition. As well, treatments that reduced stone rates also reduced these SS values. The degree of calcium phosphate (CaP) admixture was accurately matched by shifting magnitudes of COM and Br SS. As well, increasing CaP content was associated with falling urine citrate and rising urine pH, suggesting renal tubular acidosis. We conclude that sparse urine SS measurements accurately track stone admixtures, and are a reliable index of average renal and urine SS.
authors.affiliation: Department of Medicine, University of Chicago, Illinois, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Parks
authors.forename: M
authors.initials: M
authors.lastname: Coward
authors.forename: F L
authors.initials: FL
authors.lastname: Coe
mesh_terms: D002129:Calcium Oxalate / Q000032:analysis / Q000652:urine; D002130:Calcium Phosphates / Q000032:analysis / Q000652:urine; D016022:Case-Control Studies; D003460:Crystallization; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000737:chemistry* / Q000209:etiology / Q000652:urine*; D008297:Male; D014527:Uric Acid / Q000032:analysis / Q000652:urine
chemical_list: D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D002129:Calcium Oxalate; D014527:Uric Acid; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous; C494366:calcium phosphate, dibasic, dihydrate