(P11-064-23) Environmental Elements and Cardiovascular Diseases: A Series of Systematic Reviews of Observational Studies and Meta-Analysis

Objectives: To conduct a systematic review and meta-analysis of human studies investigating the role of environmental exposure to multiple metals in the development of cardiovascular diseases.

Methods: Studies reporting risk estimates for total cardiovascular disease (CVD), coronary heart disease (CHD), and stroke according to exposures to arsenic, lead, cadmium, mercury, copper, selenium, zinc, iron, magnesium, chromium, manganese, molybdenum, vanadium, tungsten, and cobalt were included. Relevant information on study characteristics, metal exposures, and outcomes was abstracted in accordance with PRISMA guidelines. Sources for heterogeneities were explored via direct plotting of effect size and variance according to study characteristics. Estimates for relative risks were standardized to a common scale and pooled across studies for each metal marker.

Results: We identified 101 unique studies comprising 1,816,552 non-overlapping men and women. Comparing highest versus lowest levels of metal exposure, greater exposure to cadmium and copper was directly associated with an elevated risk of CVD. Exposure to lead was independently associated with higher risk of stroke, whereas exposure to arsenic, cadmium, and lead were directly associated with an increased risk of CHD. Increased magnesium exposure was associated with a decreased risk of both CHD and CVD. Zinc, selenium, mercury, iron, and tungsten each were not independently associated with increased risk of CVD, CHD, or stroke. However, individuals in the highest category of iron exposure with a past medical history of diabetes and hypercholesterolemia were at increased risk of CHD. In subgroup analysis, men with greater exposure to iron and women exposed to increased levels of cadmium were at higher risk of stroke.

Conclusions: In this series of systematic reviews and meta-analyses of prospective cohort studies, exposure to arsenic, lead, cadmium, and copper was each found to be independently associated with risk of CVD, CHD, and stroke, while magnesium was associated with decreased risk. Several sources of heterogeneities were identified, including sex and past medical history, as well as the potential synergistic or antagonistic effect of multiple metal exposure, which warrants further investigation in large and high-quality prospective cohorts of diverse populations.

Funding Sources: N/A