Epidemiology and risk factors of urolithiasis: insights from SKIPOGH, a population-based cohort study in Switzerland

Kidney stones represent a growing global health concern, with a lifetime prevalence estimated at 7%-13% in North America and 1%-5% in Asia, but European data are scarce. We assessed the prevalences and incidence of kidney stones in the Swiss adult population and identified associated factors.

The Swiss Kidney Project on Genes in Hypertension (SKIPOGH) is a multicenter cohort including 1128 participants recruited from the general population of Lausanne, Geneva and Bern (2009-12). All underwent renal ultrasound at baseline and completed a standardized questionnaire. Predefined demographic, lifestyle and clinical variables included age, sex, BMI, education, smoking, physical activity, hypertension, diabetes, history of kidney stones, laboratory and urinary parameters. A follow-up visit was performed 3 years later. Logistic regression analysis was performed to identify factors associated with kidney stone prevalence at baseline and 3-year incidence of newly formed stones.

Ultrasound-detected kidney stones were present in 5.6% (6.1% men and 5.1% women). The 3-year incidence of new stones was 4.3% (4.1% men, 4.6% women). In multivariable logistic regression analysis, diabetes mellitus [odds ratio (OR) 2.93, 95% confidence interval (CI) 1.05-8.21, P = .04], a family history of kidney stones (OR 9.96, 95% CI 4.53-21.91, P < .01) and higher serum creatinine (OR 1.02 per µmol/L, 95% CI 1.00-1.04, P = .02) were associated with the prevalence of kidney stones. Active smoking (OR 2.49, 95% CI 1.07-5.78, P = .03), lower physical activity score (OR 0.82, 95% CI 0.67-1.00, P = .05) and a personal history of kidney stones (OR 33.0, 95% CI 12.4-87.6, P < .01) were associated with the 3-year incidence of kidney stones.

In this Swiss cohort, the prevalence of kidney stones was lower than that reported in North America but higher than in Asian populations. Diabetes mellitus, family history of kidney stones were the strongest risk factors for prevalent stones, while a personal history of kidney stones and low physical activity were predictors of incident stone formation. These data will help to inform prevention strategies.