Relationship between renal calculi and the risk of myocardial infarction and stroke: results from the EPIC-Potsdam study

Background: Renal calculi are related to obesity and metabolic syndrome and may indicate an increased risk of cardiovascular disease, but data from prospective cohort studies are sparse. Therefore, the authors investigated the association between renal calculi and the risk of cardiovascular disease endpoints in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study. Methods: The study population comprised 24,490 individuals aged mainly 35-65 years, who were free of cardiovascular diseases at recruitment (1994-1998). Information about the presence of renal calculi at baseline was ascertained via questionnaires. For all incident cases of myocardial infarction and stroke, confirmation was obtained from the attending physician. Hazard rate ratios (HR) were estimated using Cox proportional hazards regression. Results: During a mean follow-up of 8.1±1.6 years, 494 cases of cardiovascular disease were identified. Among persons with renal calculi (n=2,645), incidence rates were higher and selected cardiovascular risk factors were more common than among those without renal calculi. In multivariable adjusted models, no association between renal calculi and the risk of cardiovascular diseases (HR=1.05, 95% confidence interval (CI): 0.82-1.34) was observed. Endpoint specific analyses revealed similar results. In subanalyses restricted to fatal endpoints, a more than twofold increased risk of fatal myocardial infarction was observed in persons with renal calculi, but this association did not reach statistical significance (HR=2.33, 95% CI: 0.88-6.13). The HR of fatal stroke was 1.24 (95% CI: 0.46-3.33) in persons with renal calculi compared to those without. Conclusions: The authors observed a higher prevalence of cardiovascular risk factors in individuals with renal calculi but no independent relationship between the presence of renal calculi and the risk of myocardial infarction and stroke.