A prospective study of nonmedical prophylaxis after a first kidney stone

BJU Int. 1999 Sep;84(4):393-8. doi: 10.1046/j.1464-410x.1999.00216.x.


Objective: To assess, in a multicentre prospective randomized study, the effectiveness of specific nonmedical prophylaxis and nonspecific dietary prophylaxis in patients treated after experiencing their first idiopathic calcium-containing kidney stone.

Patients and methods: From 1991 to 1994, 242 patients with idiopathic calcium urinary stones from three urological centres were randomly assigned into two groups. In group 1 (intervention, 113 patients), a specific dietary regimen was recommended and thereafter corrected according to a comprehensive metabolic evaluation. Group 2 (control, 94 patients) underwent only minimal metabolic screening and used general dietary measures, with no regular follow-up. An increased fluid intake was recommended in both groups. After 3 years, the effectiveness of the prophylactic and dietary regimens was evaluated in 207 patients.

Results: At entry, the clinical characteristics were comparable in the two groups, with only extracorporeal lithotripsy being more frequent in group 2. Almost 80% of patients reported a high intake of meat and a low intake of dairy products. In group 1 and 2, a recurrent stone was encountered in seven (6%) and 18 (19%) patients, respectively; recurrent and growing stones were found in eight (8%) and 22 (23%) patients, respectively (P<0. 01). There was a higher incidence of bilateral residual (or untreated) stones, and Weddellite stones (P<0.001) among patients with a recurrent or growing stone. An analysis of the dynamics of the metabolic variables indicated the significance of repeated dietary counselling.

Conclusion: Specific dietary therapy, adjusted according to a metabolic evaluation, is more effective than nonspecific general dietary recommendations in preventing the formation of a second urinary stone.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Calcium / blood
  • Calcium / urine
  • Calcium, Dietary / administration & dosage
  • Female
  • Humans
  • Kidney Calculi / diet therapy
  • Kidney Calculi / metabolism
  • Kidney Calculi / prevention & control*
  • Male
  • Middle Aged
  • Prospective Studies
  • Recurrence
  • Uric Acid / blood
  • Uric Acid / urine


  • Calcium, Dietary
  • Uric Acid
  • Calcium