Metabolic and Renal Profile Differences in Pure vs Mixed Uric Acid Kidney Stones: A Retrospective Study.

Objective: Uric acid stones are commonly classified into pure uric acid stones (PUCS) and mixed uric acid stones with calcium oxalate (MUCS). This study aims to investigate the metabolic differences between PUCS and MUCS patients, in order to inform prevention strategies and guide management and follow-up care for uric acid urolithiasis.

Methods: We conducted a retrospective analysis of 88 patients diagnosed with uric acid stones (PUCS: 37, MUCS: 51). Comprehensive data were collected, including blood tests and stone composition analysis.

Results: Both PUCS and MUCS patients exhibited obesity, but only PUCS patients showed significant lipid metabolism abnormalities, with HDL levels significantly lower than in MUCS patients (p < 0.05). Renal dysfunction was observed in both groups, but was more severe in the PUCS group, as indicated by higher serum creatinine levels (p < 0.05). Additionally, serum calcium levels were significantly higher in the MUCS group compared to the PUCS group (p < 0.05). No significant differences were found in 24-hour urinary excretion of uric acid, sodium, potassium, chloride, or phosphorus between the two groups.

Conclusion: Patients with PUCS exhibit more pronounced disturbances in lipid metabolism and renal function compared to those with MUCS. It is essential to prioritize and enhance the monitoring of metabolic assessments and renal function during the postoperative follow-up of patients with PUCS.