METABOLIC RISK-FACTORS IN PATIENTS WITH FIRST-TIME AND RECURRENT STONE FORMATIONS AS DETERMINED BY COMPREHENSIVE METABOLIC EVALUATION

Objectives. To determine whether patients with recurrent calcium stone formation have more significant metabolic abnormalities compared with patients with first-time stone formation as determined by a comprehen sive metabolic evaluation. Methods. We investigated metabolic abnormal ities in 37 patients (14 men, 23 women) with first-time and 136 patien ts (83 men, 53 women) with recurrent calcium stones, stratified accord ing to sex. Calcium oxalate supersaturation indexes of Tiselius (1991) and Ogawa (1996) were also compared between the groups. In addition t o the specific metabolic abnormalities, we analyzed the total number o f such defects for each group. Results. in men, the average number of metabolic abnormalities in each patient was greater in patients with r ecurrent stones (2.20 +/- 0.86) than in those with first-time stones ( 1.46 +/- 1.27). Such a difference could only be demonstrated for women if low urine volume was excluded as a specific abnormality. Although the frequency of each abnormality was higher in patients with recurren t stones, a statistically significant difference was only noted in the frequency of hypocitraturia between women with first-time and recurre nt stone formation (11.1% versus 37.8%, P < 0.05). There were no signi ficant differences in the calcium oxalate supersaturation indexes betw een first-time and recurrent stone formation in either men or women. C onclusions. Women with recurrent stones have a higher prevalence of hy pocitraturia than women with first-time stones. Potassium citrate ther apy for prevention of urolithiasis may be especially useful for this p atient population, (C) 1998, Elsevier Science Inc. All rights reserved .