ORIGINAL RESEARCH article

Front. Public Health

Sec. Environmental Health and Exposome

Volume 13 - 2025 | doi: 10.3389/fpubh.2025.1597321

Association between exposure to blood heavy metal mixtures and overactive bladder risk among U.S. adults: A cross-sectional study

Provisionally accepted
Yanlin  ZhuYanlin Zhu1Yameng  WuYameng Wu2Yang  WangYang Wang1,3Hua  YangHua Yang4Meisheng  ZhangMeisheng Zhang3Hengxing  ZhuHengxing Zhu3Xiaoke  ChenXiaoke Chen1*
  • 1Department of Urology, Guangdong Provincial People's Hospital, Zhuhai Hospital (Jinwan Central Hospital of Zhuhai), Zhuhai, China
  • 2Department of Urology, Fuyang Hospital of Anhui Medical University, Anhui, China
  • 3Department of Urology, Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province, China
  • 4Department of Urology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China

The final, formatted version of the article will be published soon.

Background: Increasing evidence has demonstrated that exposure to environmental heavy metals harms human health. However, information regarding the impact of co-exposure to metal mixtures on the risk of overactive bladder (OAB) was limited. Our study aimed to explore the joint effects of blood heavy metal mixtures on OAB risk.Methods: Data for this study were obtained from four National Health and Nutrition Examination Survey cycles (2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018). The effects of single metals on OAB risk were explored using multivariate logistic regression. Additionally, we used weighted quantile sum (WQS), quantile-based g computation (qgcomp), and Bayesian kernel machine regression (BKMR) models to explore the combined effect of metal mixtures on OAB risk.Age-stratified subgroup analyses were conducted, and restricted cubic splines (RCS) were utilized to investigate the non-linear relationship between metals and OAB.Results: A total of 4183 individuals aged 20-80 years were included for further study. Among them, 866 (20.7%) participants had OAB. OAB patients had significantly higher blood concentrations of cadmium (Cd) and lead and lower blood concentrations of selenium and manganese than those without OAB (all P < 0.05). In the single-metal analyses, Cd significantly increased OAB risk. In the mixed-exposure analyses, the WQS and BKMR models consistently revealed a significant positive association between co-exposure to heavy metal mixtures and OAB risk, identifying Cd as the main positive driver. The young/middle-aged group exhibited similar significant associations. In the metal mixtures, Cd was the top-weighted metal for the entire population and young/middle-aged individuals, whereas mercury (Hg) held the highest weight among elderly individuals. Furthermore, we observed an underlying interaction between Cd and Hg in the BKMR model. In the sensitivity analyses, the findings from the qgcomp model validated the toxic effect of blood metal mixtures on OAB. According to the RCS regression, we identified a positive linear dose-response relationship between Cd and OAB risk.Our study identified that co-exposure to heavy metal mixtures was significantly related to OAB risk. Further research prioritizing low-dose, real-world exposure to metal mixtures in vulnerable populations (e.g., elderly, high-risk occupations) is essential to translate our findings into preventive strategies and regulatory policies.

Keywords: heavy metals, mixture, Co-exposure, overactive bladder, NHANES

Received: 21 Mar 2025; Accepted: 20 May 2025.

Copyright: © 2025 Zhu, Wu, Wang, Yang, Zhang, Zhu and Chen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Xiaoke Chen, Department of Urology, Guangdong Provincial People's Hospital, Zhuhai Hospital (Jinwan Central Hospital of Zhuhai), Zhuhai, China

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