Gallstones increase the risk of developing renal stones: a nationwide population-based retrospective cohort study

This study identifies the effects of gall stone on the risks of developing renal stone in a nationwide cohort study.

Studies on the association between gall stone and renal stone are scarce.

We identified patients with gallstones using the catastrophic illness registry of the Taiwan National Health Insurance Research Database (NHIRD). We selected a comparison cohort, random frequency-matched by age, sex and index year, from the general population. We analyzed the risk of renal stones by using Cox proportional hazards regression models for sex, age and comorbidities.

Of the 23.74 million people in the database, we followed 25 258 gallstone patients (54.5% female) and 101 029 control patients. The risk of developing renal stones was 1.68-fold greater in gallstone patients, compared with patients without gallstones after adjusting for age, sex and comorbidities. The substantially increased risk of renal stones was also significant in gallstone patients regardless of comorbidities. In the follow-up period <1 year, the adjusted hazard ratio was 2.51 (95% CI = 2.25-2.80) compared to non-gallstone group. The cumulative incidence of renal stone in the gallstone group was higher than in the non-gallstone group (P < 0.0001, in the log-rank test).

This nationwide cohort study demonstrates that the risk of renal stones is significantly higher in gallstone patients, compared with the general population. This study provides information to enable physicians to implement adequate prevention measures to decrease both stones formation.