Metabolic evaluation in patients with recurrent calcium oxalate stones

Objective: This study aimed to evaluate the metabolic changes in patients with recurrent calcium oxalate stones.

Materials and methods: We evaluated 143 patients with recurrent oxalate stones and measured serum calcium, phosphate, creatinine, urate, and parathormone. In addition, 24-h urinary output was monitored and collected for the measurement of total volume, pH, citrate, calcium, urate, oxalate, phosphorus, sodium, and magnesium.

Results: The mean age of the patients was 42.8±10.8 years, and 132 out of 143 patients (92.3%) had metabolic abnormalities. There were no metabolic abnormalities in only 11 (7.7%) patients. Thirty (20.1%) patients only had one metabolic abnormality, and 102 (71.3%) patients had multiple metabolic abnormalities. Hyperoxaluria was the major metabolic abnormality (64.4%), but we also detected low urinary volume, hypercalciuria, hypocitraturia, hypernatriuria, and hyperuricosuria in 66 (46.2%), 47 (32.8%), 47 (32.8%), 44 (30.8%), and 21 (14.7%) patients, respectively.

Conclusion: There were several metabolic abnormalities in patients with recurrent calcium oxalate stones, and the most important were hyperoxaluria, hypercalciuria, hypocitraturia, and low urinary volume. These metabolic abnormalities should be detected and corrected to prevent the recurrence of stones.