Long-term mortality risk in US adults with a history of kidney stones: results from NHANES III with over 30 years of follow-up.

Purpose: To investigate the association between a history of kidney stones and long-term all-cause and cause-specific mortality in a nationally representative sample of US adults.

Methods: This observational study included adults who participated in the Third National Health and Nutrition Examination Survey (NHANES III, 1988-1994). Kidney stone history was self-reported during the survey. Vital status and causes of death during follow-up were ascertained via the National Death Index through December 31, 2019. Weighted Cox proportional hazards models estimated hazard ratios (HRs) for the association between kidney stone history and all-cause, cardiovascular, cancer, and renal mortality. Models were progressively adjusted for demographic, socioeconomic, and clinical variables to account for confounding factors.

Results: The final analytic sample comprised 19,578 participants (weighted kidney stone prevalence = 5.3%) with 420,947 person-years of follow-up (range: 0-31 years). Stone formers were older than non-stone formers (mean age 54 vs. 43 years) with a higher prevalence of comorbidities. In the unadjusted model, kidney stone history was associated with increased all-cause mortality risk (HR = 1.82; 95% CI 1.63-2.03). However, this association was attenuated in the fully adjusted model (HR = 0.89; 95% CI 0.79-1.01). No significant differences were observed between groups for cardiovascular (HR = 0.87; 95% CI 0.73-1.03), cancer (HR = 1.01; 95% CI 0.74-1.37), or renal mortality (HR = 0.99; 95% CI 0.31-3.16) in fully adjusted models.

Conclusion: In this nationally representative cohort of US adults, a history of kidney stones was not associated with an increased risk of all-cause or cause-specific mortality after adjustment for confounders.