Metabolic abnormalities and recurrence in high-risk urinary stone formers: A prospective cohort study

High-risk urinary stone formers are advised to undergo comprehensive metabolic assessment and targeted prophylaxis; however, recurrence outcomes under guideline-based prevention programs remain uncertain.

We conducted a prospective, single-center observational cohort study including adult high-risk stone formers rendered stone-free after surgical/endourological treatment. All patients underwent standardized blood tests, 24-hour urine evaluation, and stone composition analysis. Patients with at least one metabolic abnormality received risk factor-specific therapy, whereas those without abnormalities received non-specific measures and lifestyle counseling. Recurrence was defined as a newly detected stone ≥3 mm on follow-up imaging.

Sixty-four patients were included (mean age 33.47 ±10.32 years; 60.9% male). At least one metabolic abnormality was identified in 42 patients (65.6%); hypocitraturia was the most frequent abnormality (53.1%). Metabolic syndrome was present in 16 patients (25.0%) and was more common among patients with metabolic abnormalities (33.3% vs 9.1%; p = 0.033). Over a mean follow-up of 24.5 months, recurrence occurred in 10 patients (15.6%). Recurrence rates were 16.7% (7/42) in the targeted-therapy group and 13.6% (3/22) in the non-specific group (p = 0.749), corresponding to a relative risk of 1.22 (95% confidence interval 0.35-4.27). Among patients who experienced recurrence (n = 10), the time to recurrence was 11.8 ±5.69 months (median 12.5 months; range 4-19 months).

In this high-risk cohort, metabolic abnormalities were common, and metabolic syndrome clustered with metabolic risk factors. Between-group recurrence estimates were imprecise; larger studies with robust adjustment for baseline risk and adherence are needed. The observational, risk-stratified design precludes causal inference regarding the effectiveness of targeted medical metaphylaxis.