Risk factors of stone recurrence in idiopathic renal calculi

ABSTRACT

Recurrent kidney stone [RKS] is a long-term problem causing a significant morbidity. The study was conducted to determine the rate of recurrence of calcium oxalate [Ca-Ox] kidney stones at 5 years after the first symptomatic stone, and to identify the risk factors of stone recurrence and their predictive values. The study included 233 patients with idiopathic Ca-Ox kidney stones. Medical History abbreviated food frequency questionnaire, and laboratory investigations were used to collect the data. The relative risk and 95% confidence interval of stone recurrence for each hypothesized risk factor was determined. Multivariate analysis using logistic regression [LR] was used to identify the significant risk factors and their negative and positive predictive values. The overall rate of recurrence was 61.8%. Young agent the first stone episode, male sex, positive family history [FH] and low fluid and high protein intake were found to be significant risk factors of stone recurrence. No significant differences were identified between recurrent and first stone formers for any of the laboratory measurements. The positive and negative predictive values of a model containing the significant risk factors were 78.3% and 54.4% respectively, with an overall prediction of 69.1%. Ca-Ox kidney stones have a high rate of recurrence. Fluid and protein intake appears to play an important role in kidney stone recurrence. We cannot, identify a good predictive model for stone recurrence so, we recommend pursuing diagnostic and therapeutic approaches for all first-stone formers