Association between oxidative balance score and kidney stone disease: a prospective cohort study from the UK Biobank

Oxidative stress has been implicated in the development of kidney stone disease. The Oxidative Balance Score (OBS), which integrates dietary and lifestyle pro- and antioxidant exposures, provides a comprehensive measure of overall oxidative balance. This study aimed to examine the prospective associations between OBS, its dietary (DOBS) and lifestyle (LOBS) components, and kidney stone disease. This prospective study included 171,576 UK Biobank participants without a hospital diagnosis of kidney stone disease. Inverse probability of treatment weighting was used to achieve covariate balance across groups. Weighted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), with restricted cubic spline analyses used to examine potential non-linear associations. Subgroup analyses were performed to evaluate potential effect modification; sensitivity analyses were conducted to assess the robustness of the findings. During 2,081,286 person-years of follow-up, 1,909 incident kidney stone disease events were identified. Each 1-point increment in OBS was associated with a lower risk of kidney stone disease (HR: 0.99, 95% CI: 0.98–0.99). Participants in the highest OBS quartile had a significantly lower risk compared with those in the lowest (HR: 0.81, 95% CI: 0.71–0.93). For DOBS, compared with that in the lowest quartile, a significantly lower risk was observed only in the third quartile (HR: 0.87, 95% CI: 0.76–0.98). In contrast, LOBS demonstrated a progressively lower risk across relatively high quartiles (Q4 vs. Q1: HR: 0.59, 95% CI: 0.49–0.71). Subgroup analyses showed that the associations remained significant among men, participants aged ≤ 60 years, and those without diabetes. Sensitivity analyses yielded similar results. Relatively high OBS was associated with a lower risk of kidney stone disease. DOBS and LOBS contributed to this inverse association while exhibiting distinct association patterns. These findings provide additional epidemiological evidence regarding oxidative balance and kidney stone disease risk and highlight potential opportunities for prevention strategies targeting modifiable dietary and lifestyle factors.