title: [Importance of the deficit of crystallization inhibitors in the etiopathogenesis of urolithiasis].
abstract: BACKGROUND
  five percent of consultations at the Emergency Room of Catholic University Hospital are due to nephrolithiasis. The causes of this high frequency remain unknown.
  
  
  OBJECTIVE
  to know the main metabolic and anatomic factors involved in the genesis of neprholithiasis.
  
  
  METHODS
  forty one patients (31 male) were studied presenting with a renal colic were studied as soon as the acute episode subsided and without diet modifications. Fasting blood calcium and creatinine and 24 h urine calcium, uric acid, citrate, magnesium and pH were measured and an intravenous pyelogram was performed. Twenty one subjects without a history of nephrolithiasis were used as controls.
  
  
  RESULTS
  Patients with nephrolithiasis did not differ from controls in urinary calcium (159 +/- 67 and 172 +/- 67 mg/24 h respectively), uricosuria (417 +/- 171 and 431 +/- 121 mg/24 h respectively) or urinary magnesium (55 +/- 19 and 62 +/- 21 mg/24 h respectively, whereas urinary citrate was lower (219 +/- 172 vs 319 +/- 179 mg/24 h in controls p < 0.05). All patients had normal renal functions, urinary acidification and intravenous pyelogram. Seven percent of patients with nephrolithiasis had hypercalciuria, 2.4% had hyperuricosuria. 68.3% had a low urinary citrate and 44.4% had low urinary magnesium.
  
  
  CONCLUSIONS
  in this sample, there is a strong association of nephrolithiasis with low levels of crystallization inhibitors in special with urinary citrate, a crystallization inhibitor.
authors.affiliation: Departamento de Endocrinología, Metabolismo y Nutrición, Universidad Católica de Chile.
authors.forename: C
authors.initials: C
authors.lastname: Fardella
authors.forename: M
authors.initials: M
authors.lastname: Lastra
authors.forename: A
authors.initials: A
authors.lastname: Rojas
authors.forename: M
authors.initials: M
authors.lastname: Toro
authors.forename: C
authors.initials: C
authors.lastname: Pinochet
authors.forename: R
authors.initials: R
authors.lastname: Rosales
authors.forename: F
authors.initials: F
authors.lastname: Retamal
authors.forename: Y
authors.initials: Y
authors.lastname: Mellado
authors.forename: F
authors.initials: F
authors.lastname: López
authors.forename: E
authors.initials: E
authors.lastname: Saa
mesh_terms: D000328:Adult; D002118:Calcium / Q000378:metabolism; D016022:Case-Control Studies; D003460:Crystallization; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011687:Purines / Q000378:metabolism; D013054:Spectrophotometry, Atomic; D014545:Urinary Calculi / Q000209:etiology* / Q000378:metabolism
chemical_list: D011687:Purines; D002118:Calcium
vernacular_title: Importancia del deficit de inhibidores de la cristalización en la etiopatogenia de la urolitiasis.