Metabolic abnormalities in patients with nephrolithiasis: comparison of first-episode with recurrent cases in Southern Iran

Abstract

Metabolic disorders are one of the etiologic factors in renal stone formation. The aim of present study was to evaluate prevalence of metabolic disorders in patients with renal stone. From 572 patients referring to our urologic clinics, 376 patients participated in the study. Patients were divided to first time stone former (group A) and recurrent renal stone (group B). Twenty-four hour urine specimens were obtained for urinary calcium, oxalate, magnesium, citrate, uric acid, phosphor and 24-h urine volume. Venous blood samples were obtained evaluating serum phosphate, uric acid, and calcium. The prevalence of each metabolic disorder was detected, and two groups were compared regarding metabolic disorders. The prevalence of renal stone in male patients was 63.04% versus 36.96% in female patients (P < 0.05). The most common abnormality observed in patients was low 24-h urine volume (58.24%) followed by hypercalciuria (17.18%) and hyperuricosuria (15.15%). Hyperuricemia was found in 6 first time stone former patients and 14 patients with recurrent renal stone (P = 0.04). There was no statistically significant difference between group A and B in other metabolic abnormalities (P > 0.05). Low 24-h urine volume was the most common abnormalities in patients with nephrolithiasis in our region. Metabolic evaluation must be performed in all patients with renal stone even those with first time stone formation.