Sex-Specific Effects of Combined Heavy Metal Exposure on Blood Pressure: A Bayesian Kernel Machine Regression Analysis

High blood pressure (BP) is a significant risk factor for heart and brain diseases. Previous studies have suggested that heavy metals including lead (Pb), mercury (Hg), and cadmium (Cd) contribute to hypertension. This study examined the combined effects of heavy metals on blood pressure, considering sex differences. A health impact survey was conducted among 561 residents living near waste incineration facilities in Cheongju, Korea. Blood samples were analyzed for heavy metal concentrations and blood pressure was measured. Multiple linear regression and Bayesian kernel machine regression (BKMR) methods were used to evaluate the relationship between heavy metal exposure and BP. Men had higher blood Hg and Pb concentrations, whereas women had higher Cd levels. Multiple linear regression analysis revealed no significant association between heavy metals and systolic blood pressure. However, Cd was significantly associated with increased diastolic blood pressure for the total group and women, whereas Pb was associated with increased diastolic blood pressure in men. In the BKMR analysis, the joint effect of the three metals was significantly associated with diastolic blood pressure for individuals below the 45th percentile and above the 55th percentile in men. These findings underscore the importance of considering sex differences in environmental health studies and public health strategies.