Association of metabolic syndrome and its components with the risk of urologic cancers: a prospective cohort study

OBJECTIVE: To investigate the association between metabolic syndrome (MetS) and its components and the risk of developing urologic cancers. METHODS: This study included 101,510 observation subjects from May 2006 to December 2007. The subjects received questionnaires and were subjected to clinical and laboratory examinations to collect data on baseline population characteristics, waist circumference (WC), blood pressure (BP), blood glucose, blood lipids, lifestyle, and past disease history. Finally, follow-up was conducted from the date of recruitment to December 31, 2019. Cox proportional hazards modelling was applied to analyze the association between MetS and its components and the risk of developing urologic cancers. RESULTS: A total of 97,975 observation subjects met the inclusion criteria. The cumulative follow-up period included 1,209,178.65 person-years, and the median follow-up time was 13.03 years. During the follow-up period, 485 cases of urologic cancers (165 cases of kidney cancer, 134 cases of prostate cancer, 158 cases of bladder cancer, and 28 cases of other urologic cancers) were diagnosed. The log-rank test results for the cumulative incidences of urologic cancer, kidney cancer, and prostate cancer indicated significant (P < 0.01) differences between the MetS and non-MetS groups (0.70% vs. 0.48%, 0.27% vs. 0.15%, and 0.22% vs. 0.13%, respectively). Compared to the non-MetS group, the risk of developing urologic [HR (95% CI) = 1.29 (1.08–1.55)], kidney [HR (95% CI) = 1.74 (1.28–2.37)], and prostate [HR (95% CI) = 1.47 (1.04–2.07)] cancers was significantly higher in the MetS group. In the MetS group, elevated BP increased the risk of developing of urologic cancer [HRs (95% CI) = 1.35 (1.10–1.66)] and kidney cancer [HR (95% CI) = 1.74 (1.21–2.51)], while central obesity increased the risk of developing prostate cancer [HR (95% CI) = 1.68 (1.18–2.40)]. CONCLUSIONS: MetS increased the risk of developing urologic, kidney, and prostate cancers but had no association with the development of bladder cancer.