Comparison of Metabolic Risk Factors in Patients with First-time and Recurrent Stone Formations

Oh, Seung Young; Moon, Young Tae

Abstract

PURPOSE: The aim of this study was to determine whether patients with recurrent stone formations have significant metabolic risk factors compared to patients with first-time stone formations.
MATERIALS AND METHODS
456 patients who participated in the stone metabolic study at Chung-Ang University Hospital between January 1, 2001 and June 30, 2002 were selected as subjects. 347 patients (211 males, 136 females) with first-time stone formations and 109 patients (77 males, 32 females) with recurrent stone formations were selected. The blood test and 24-hour urine test were categorized and grouped according to: 1) gender; 2) age brackets of 40 and under, 40-49, and 60 and over; 3) and gender-based age bracket distribution.
RESULTS
Hypocitraturia was the most common metabolic abnormality in both males and females and in all age groups. Hypocitraturia, in particular, was shown to have more significant associations (p<0.05) in female patients in their 40s and 50s with recurrent stone formations (75%) compared to female patients of the same age range with first-time stone formations (38.6%). In addition, a small urine volume was found to have similar significant associations with these subject groups (p<0.05) with respect to patients with first-time stone formations and recurrent stone formations. Female Patients (especially those in their 40s and 50s) with recurrent stone formations (242.1+/-158.5) were found to have a higher probability (p<0.05) of hypocitraturia than patients with first-time stone formation (419.9+/-242.3).
CONCLUSIONS
In women with recurrent stone formation, hypocitraturia and low urine volume are the risk factors that differentiate them from patients with first-time stone formation. The correction of hypocitraturia & low urine volume may significantly reduce the patients' chances for recurrent stone formation.