Biological aging mediates the associations between urinary metals and hypertension: Insights from cross-sectional studies on Chinese and American adults

Accelerated aging and environmental factors are increasingly recognized as significant contributors to hypertension. This study aims to assess the associations between urinary metal and hypertension risk while also exploring the mediating effects of biological aging. The study encompassed 3389 individuals from a Chinese cohort and 5965 individuals from the National Health and Nutrition Examination Survey (NHANES) cohort. Urinary metal concentrations were measured in a Chinese cohort, while those for NHANES were obtained directly from the database. Biological age was calculated using the Klemera and Doubal method. Our results showed that urinary barium (Ba), copper (Cu), manganese (Mn) and zinc (Zn) in the Chinese population, as well as antimony (Sb) and tungsten (W) in the United States (US) population were associated with an increased risk of hypertension. Interestingly, Ba and lead (Pb) appeared to reduce the risk of hypertension in the US population. Mediation analysis demonstrated that accelerated biological aging significantly mediated the relationship between Cu, Zn, Ba and Pb and hypertension, accounting for 12.39 %, 23.04 %, 17.62 %, and 18.71 % of the total effect, respectively. This study suggested that exposure to metals accelerates aging, ultimately exacerbating the progression of hypertension despite variations in the relative contributions of different metals to this condition. Moreover, it underscored the potential benefits of moderate physical activity and tea consumption as interventions to mitigate hypertension risk and slow biological aging.