Association Between Serum Copper and Overactive Bladder in Adults: A Cross-Sectional Study

Copper is one of the heavy metals that people are frequently exposed to in their daily lives and has been reported to be associated with a variety of diseases. However, the association between serum copper and the risk of overactive bladder (OAB) is currently unknown. The purpose of this study was to assess the potential risky association between serum copper and OAB in adults. A cross-sectional study involving 4600 adult participants from the National Health and Nutrition Examination Survey (NHANES) 2011-2016 was performed. OAB was assessed by the Overactive Bladder Symptom Score (OABSS). The association between serum copper and OAB was evaluated using univariate and multivariate weighted logistic regression models and subgroup analyses. Ultimately, 962 OAB participants and 3638 non-OAB participants were included. Serum copper concentrations were significantly higher in the OAB group compared to the non-OAB group (127.50 vs. 117.86). Univariate weighted logistic regression demonstrated that the highest tertile of serum copper was positively associated with the risk of OAB compared to the lowest tertile (OR = 2.761, 95% CI: 2.139-3.565, p < 0.001). Serum copper was still positively correlated with OAB after adjusting for all covariates (OR = 1.551, 95% CI: 1.140-2.109, p = 0.005). And the trend test was also statistically significant (p for trend = 0.004). Subgroup analyses indicated that the association between serum copper and OAB was significant in females (OR = 1.630, 95% CI: 1.064-2.497, p = 0.025). Excess serum copper is positively correlated with OAB risk, especially in females. The toxic effects of copper must be viewed with caution, and prospective cohort and mechanistic investigations are needed to validate the causal effects of copper on OAB.