Combined Effects of Environmental Metals and Physiological Stress on Lipid Dysregulation.

Background: Cardiovascular diseases (CVD) are a leading cause of mortality worldwide, influenced by genetic, environmental, and behavioral factors. This study examines the relationship between heavy metal exposure, chronic physiological stress (allostatic load), and lipid profiles, which are markers of CVD risk, using data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018.

Methods: We utilized structural equation modeling (SEM) to explore the associations between blood levels of lead, cadmium, allostatic load (AL), and lipid measures (low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides). The AL index was derived from cardiovascular, inflammatory, and metabolic biomarkers and categorized into quartiles to identify high-risk individuals, with an index out of 10 subsequently developed.

Results: The SEM analysis revealed that both heavy metal exposure and allostatic load are significantly associated with lipid profiles. Higher levels of lead and cadmium were associated with increased LDL and triglycerides, while higher AL scores were linked to increased LDL and triglycerides and decreased HDL levels. Age was also a significant factor, showing positive correlations with LDL and triglycerides, and a negative correlation with HDL.

Conclusions: This study underscores the multifactorial nature of CVD, highlighting the combined impact of environmental pollutants and physiological stress on lipid dysregulation. These findings suggest the need for integrated public health strategies that address both environmental exposures and chronic stress to mitigate cardiovascular risk. Further research is warranted to explore the underlying mechanisms and develop targeted interventions.