The association between metabolic syndrome and the risk of urothelial carcinoma of the bladder: a case-control study in China

Background: Evidence of the association of metabolic syndrome (MetS) with cancer risk is accumulating. However, uncertainties still exist as to the link of MetS with bladder cancer. This study aimed to assess the relationship between MetS and the risk of urothelial carcinoma of the bladder (UC) in a Chinese population. Methods: We retrospectively analyzed clinicopathological data of 972 newly diagnosed UC patients and 1098 cancer-free controls matched to the cases by age and gender. Odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated using unconditional logistic regression in both unadjusted and adjusted models. Results: MetS was not significantly associated with the overall UC risk (p = 0.08). However, a significant association of MetS with UC was observed in female patients (p = 0.006). Diabetes mellitus (crude OR 1.339, 95 % CI 1.079-1.662, p = 0.008; adjusted OR 1.767, 95 % CI 1.308-2.386, p < 0.001) and hypertriglyceridemia (crude OR 1.245, 95 % CI 1.018-1.522, p = 0.033; adjusted OR 1.254, 95 % CI 1.020-1.542, p = 0.032) were significantly associated with UC risk. As the number of MetS components increased, the UC risk was elevated. Having three or more (versus zero) components of MetS was significantly related to risk of overall UC (OR 1.315; 95 % CI 1.006-1.719; p = 0.045) and non-muscle invasive bladder cancer (OR 1.354; 95 % CI 1.019-1.798; p = 0.037). Conclusions: The present study indicated a marginal association between MetS and UC risk, and a significant association with UC risk in female patients. The results need to be evaluated in large-scale prospective cohorts.