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Urinary Supersaturation in a Randomized Trial Among Individuals with Recurrent Nephrolithiasis Comparing Empiric
Ryan S Hsi1,2, Aaron X Lee3, Tatsuki Koyama3
1Department of Urology, University of California, Orange, California.
The Journal of Urology
|June 30, 2026
Summary
Selective versus empiric therapy for kidney stone prevention showed no significant difference in urinary stone risk. This short-term trial found both strategies equally effective in managing urinary supersaturation of calcium oxalate and calcium phosphate.
Area of Science:
- Nephrology
- Urology
- Metabolic Disorders
Background:
- Recurrent idiopathic calcium stone disease poses a significant health burden.
- Urinary supersaturation of calcium oxalate and calcium phosphate are key drivers of stone formation.
- Effective prevention strategies are crucial for managing patients with high-risk for stone recurrence.
Purpose of the Study:
- To compare the efficacy of selective (testing-guided) therapy versus empiric (untested) therapy in managing urinary supersaturation.
- To evaluate the impact of these strategies on urinary calcium oxalate and calcium phosphate levels.
- To assess differences in urinary parameters and stone risk between empiric and selective treatment approaches.
Main Methods:
- A single-center randomized trial involving adult patients with recurrent idiopathic calcium stone disease.
- Participants were assigned to either an empiric or selective treatment strategy.
- 24-hour urine testing was performed at baseline, 4, and 8 weeks to guide or assess treatment efficacy.
Main Results:
- No statistically significant differences were observed in mean urinary supersaturation of calcium oxalate (4.7 vs 5.0) or calcium phosphate (1.3 vs 1.4) at 8 weeks between the empiric and selective groups.
- Urinary volume, pH, and excretion of calcium, oxalate, citrate, uric acid, and sodium also showed no significant differences between the two strategies.
- The study included 56 participants, with 29 in the empiric arm and 27 in the selective arm.
Conclusions:
- In the short term, empiric therapy and selective therapy demonstrate comparable effectiveness in preventing kidney stones among high-risk individuals.
- Neither strategy provided a statistically significant advantage in reducing urinary stone risk markers.
- Further long-term studies may be warranted to explore potential differences in outcomes or specific patient subgroups.
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