title: Kidney stones: Composition, frequency and relation to metabolic diagnosis.
abstract: Nephrolithiasis is one of the most frequent urologic diseases. The aim of this paper is to study the composition and frequency of 8854 patient kidney stones and in a subset of them their metabolic risk factors to be related to their type of calculi. Physicochemical and crystallographic methods were used to assess kidney stone composition. In a subset of 715 patients, we performed an ambulatory metabolic protocol with diagnostic purposes. From the total sample 79% of stones were made of calcium salts (oxalate and phosphate), followed by uric acid stones in 16.5%, calcium salts and uric acid in 2%, other salts in 1.9% and cystine in 0.6%. Male to female ratio was almost three times higher in calcium salts and other types of stones, reaching a marked male predominance in uric acid stones, M/F 18.8 /1.0. The major risk factors for calcium stones are idiopathic hypercalciuria, followed by unduly acidic urine pH and hyperuricosuria. In uric acid stones unduly acidic urine pH and less commonly hyperuricosuria are the most frequent biochemical diagnosis. Our results show that analysis of kidney stones composition and the corresponding metabolic diagnosis may provide a scientific basis for the best management and prevention of kidney stone formation, as well as it may help us to study the mechanisms of urine stone formation.
authors.affiliation: Instituto de Investigaciones Metabólicas, Universidad del Salvador, Buenos Aires, Argentina. E-mail: spiva@idim.com.ar.
authors.forename: Francisco R
authors.initials: FR
authors.lastname: Spivacow
authors.affiliation: Instituto de Investigaciones Metabólicas, Universidad del Salvador, Buenos Aires, Argentina.
authors.forename: Elisa E
authors.initials: EE
authors.lastname: Del Valle
authors.affiliation: Instituto de Investigaciones Metabólicas, Universidad del Salvador, Buenos Aires, Argentina.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Lores
authors.affiliation: Instituto de Investigaciones Metabólicas, Universidad del Salvador, Buenos Aires, Argentina.
authors.forename: Paula G
authors.initials: PG
authors.lastname: Rey
mesh_terms: D000328:Adult; D000367:Age Factors; D001118:Argentina / Q000453:epidemiology; D002118:Calcium / Q000378:metabolism; D018360:Crystallography, X-Ray / Q000379:methods; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007669:Kidney Calculi / Q000737:chemistry / Q000453:epidemiology* / Q000209:etiology* / Q000378:metabolism*; D008297:Male; D008659:Metabolic Diseases / Q000150:complications* / Q000453:epidemiology*; D008875:Middle Aged; D012016:Reference Values; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D014527:Uric Acid / Q000378:metabolism; D055815:Young Adult
chemical_list: D014527:Uric Acid; D002118:Calcium
keywords: kidney stone composition; metabolic diagnosis