Work

Comparison of Thiazide Versus Alkali for Kidney Stone Recurrence Among Individuals With Hypocitraturia and High Urine pH

Year: 2025

Type: article

Abstract: Rationale & Objective To compare symptomatic stone recurrence among individuals with low urinary citrate and high urine pH prescribed thiazides versus alkali. Study Design Retrospective cohort study. Setting & Participants Among Medicare beneficiaries with a 24-hour urine collection obtained between 2010-2019 individuals with hypocitraturia (≤300 mg/day for males and ≤350 mg/day for females) and high urine pH (>6.3) not previously receiving thiazides or alkali. Exposures Receipt of thiazide or alkali therapy within 6 months after the urine collection. Outcomes The incidence of a subsequent symptomatic stone event (i.e., an emergency department visit, hospitalization, or surgery). Analytical Approach Multivariable Cox modeling, adjusting for demographic and baseline 24-hour urine parameters. Results Among 1270 individuals with mean age 62.8 years, 68% female and median 3.0 years follow-up; we identified 107 and 1163 individuals receiving thiazides and alkali, respectively. Comparing those who received thiazides versus alkali, there were respective baseline differences in mean 24-hour urinary citrate (195 mg vs 171 mg, p=0.01) and calcium (209 mg vs 151 mg, p<0.001), but not urine pH (6.7 for both groups). By multivariable analysis, compared to alkali, thiazide use was associated with a lower hazard of a symptomatic stone event (HR=0.64, 95% CI 0.43-0.97, p=0.04). A sensitivity analysis matching individuals 1:1 by baseline calcium and citrate showed similar results (HR=0.44, 95% CI 0.26-0.77, p<0.01). Limitations Missing data, miscoding, residual confounding. Conclusions Compared to alkali, thiazides are associated with a reduction in symptomatic stone events. These data suggest that a trial is warranted to compare their effectiveness in patients with an alkaline urine.

Source: Kidney Medicine

DOI: 10.1016/j.xkme.2025.101145