title: An update on metabolic assessment in patients with urinary lithiasis.
abstract: OBJECTIVE
  The objective of this study was to evaluate the prevalence of urinary metabolic abnormalities in patients with urolithiasis and their potential risk factors.
  
  
  METHODS
  A total of 905 stone patients were evaluated in a prospective trial from February 2000 to January 2012. Inclusion criteria were as follows: history and/or imaging tests confirming at least 2 separate or concurrent stone episodes; creatinine clearance ≥ 60 mL/min; and negative proteinuria and urine culture. Metabolic study consisted of two 24-h urine collections separated by a period of 3 months for dosing Ca, P, uric acid, Na, K, Mg, oxalate, and citrate. Serum levels of Ca, P, uric acid, Na, K, Cl, Mg, creatinine, and glucose were assessed. Urinary pH and urinary acidification tests were also performed.
  
  
  RESULTS
  A total of 735 patients were included, with a mean age of the 40 ± 1.0 year; 96.8 % of patients presented diagnosis of one or more urinary metabolic abnormalities. The most prevalent metabolic abnormalities were hypercalciuria (50.8 %), hypomagnesuria (50.1 %), hypocitraturia (35.4 %), and hyperuricosuria (30.7 %). Body weight was significantly higher in patients with hyperuricosuria (81.20 ± 15.67 kg vs. 70.17 ± 14.13 kg, respectively, p = 0.001). Urinary sodium was significantly higher in patients with hypercalciuria than without (246.97 ± 103.9 mEq/24 h vs. 200.31 ± 91.6 mEq/24 h, p = 0.001) and hyperuricosuria compared to without (283.24 ± 107.95 mEq/24 h vs. 198.57 ± 85.3 mEq/24 h, p = 0.001).
  
  
  CONCLUSIONS
  Urinary metabolic disturbances were diagnosed in 96.8 % of patients in the study. These results warrant metabolic study and follow-up in patients with recurrent lithiasis in order to decrease recurrence rate through specific treatments, modification in alimentary, and behavioral habits.
authors.affiliation: Urinary Lithiasis Metabolism Service, Medical School of Botucatu - UNESP, Botucatu, SP, 18618-970, Brazil, btamaro@uol.com.br.
authors.forename: Carmen Regina Petean Ruiz
authors.initials: CR
authors.lastname: Amaro
authors.forename: Jose
authors.initials: J
authors.lastname: Goldberg
authors.forename: Patricia Capuzzo
authors.initials: PC
authors.lastname: Damasio
authors.forename: Victor Augusto
authors.initials: VA
authors.lastname: Leitão
authors.forename: Benjamin
authors.initials: B
authors.lastname: Turney
authors.forename: Carlos Roberto
authors.initials: CR
authors.lastname: Padovani
authors.forename: João Luiz
authors.initials: JL
authors.lastname: Amaro
mesh_terms: D000328:Adult; D019343:Citric Acid / Q000378:metabolism*; D003404:Creatinine / Q000378:metabolism; D005260:Female; D006801:Humans; D053565:Hypercalciuria / Q000453:epidemiology*; D006959:Hyperoxaluria / Q000453:epidemiology*; D008274:Magnesium / Q000378:metabolism*; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D012964:Sodium / Q000378:metabolism; D014527:Uric Acid / Q000378:metabolism*; D052878:Urolithiasis / Q000150:complications / Q000378:metabolism*
chemical_list: D014527:Uric Acid; D019343:Citric Acid; D012964:Sodium; D003404:Creatinine; D008274:Magnesium