Kidney stones are associated with metabolic syndrome in a health screening population: a cross-sectional study

Background: In parallel with the rise in obesity and metabolic syndrome (MetS), kidney stones are becoming more common. In this study, the relationship between MetS components and kidney stones in a health screening population was examined. Methods: Subjects who underwent health checkups in the Health Promotion Centre of Sir Run Run Shaw Hospital of Zhejiang University between January 2017 and December 2019 were recruited for this study. In this cross-sectional study, 74,326 participants were aged 18 or older. MetS diagnostic criteria were based on the joint statement of the International Diabetes Federation (IDF) and other associations on MetS in 2009. The association between MetS and its components with kidney stones was examined using multivariable logistic regression. Results: A total of 74,326 participants took part in this cross-sectional study, including 41,703 men (56.1%) and 32,623 women (43.9%). There were 24,815 (33.4%) patients with MetS and 2,032 (2.7%) patients with kidney stones. The prevalence of kidney stones was 3.3% in subjects with MetS and 2.4% in subjects without MetS (P<0.001). The odds ratio and 95% confidence interval (CI) for kidney stones in MetS patients were 1.157 (95% CI: 1.051-1.273). Accordingly, the prevalence of kidney stones showed a statistically significant trend of gradual increase as the number of MetS components increased (P<0.001). Among the components of MetS, elevated waist circumference, reduced high-density lipoprotein cholesterol (HDL-C), and elevated fasting blood glucose (FBG) were independent influencing factors of kidney stones (P< 0.001), with odds ratios of 1.205 (95% CI: 1.085-1.337), 1.222 (95% CI: 1.105-1.351) and 1.335 (95% CI: 1.202-1.482), respectively. Conclusions: MetS is an independent risk factor for kidney stones. Therefore, the control of MetS may help reduce the incidence of kidney stones.