title: Data on the degree of saturation of urine with respect to calcium hydrogen phosphate in hypercalciuric children and renal stone formers.
abstract: Calcium hydrogen phosphate (CaHPO4) was considered as one of the main factors governing renal calculus formation. The degree of saturation with respect to this phase was therefore calculated in urines of 36 hypercalciuric children (20 absorptive, 16 renal subtype) with isolated hematuria, 10 renal stone patients, and 30 healthy controls. The effects of low calcium diet and hydrochlorothiazide treatment were also investigated in the patient groups. The results were compared to the widely used indicator of hypercalciuria (Ca/Cr ratio). Urines of both the hypercalciuric and the normocalciuric renal stone patients were saturated on basal conditions. On low calcium diet, 12 children of the absorptive hypercalciuric, 13 of the renal hypercalciuric and 7 of the renal stone-forming children had their urines in the saturated zone - irrespective of the evolution of Ca/Cr ratio. Thiazide normalized the activity product of CaHPO4 in all groups. The use of the Ca/Cr ratio as the sole parameter in the investigation of children with isolated hematuria and hypercalciuria or calcium nephrolithiasis seems to be insufficient; simultaneous determinations of the state of saturation of urines is recommended. This technique should also allow a quantitative assessment of the various therapeutic regimens recommended.
authors.affiliation: First Department of Pediatrics, Semmelweis University Medical School, Budapest, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Szabó
authors.forename: G S
authors.initials: GS
authors.lastname: Reusz
authors.forename: T
authors.initials: T
authors.lastname: Tulassay
mesh_terms: D002130:Calcium Phosphates / Q000652:urine*; D002136:Calcium, Dietary / Q000008:administration & dosage; D002648:Child; D006801:Humans; D006852:Hydrochlorothiazide / Q000627:therapeutic use; D007669:Kidney Calculi / Q000652:urine*
chemical_list: D002130:Calcium Phosphates; D002136:Calcium, Dietary; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D006852:Hydrochlorothiazide; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous