Top Things to Know: Contaminant Metals as CV Risk Factors
Published: June 12, 2023
- Traditional risk factors and biological mechanisms incompletely define atherosclerotic risk. Environmental cardiology recognizes that exposure to pollutants, including contaminant metals, constitutes an important, modifiable component of cardiovascular disease risk.
- This statement prioritizes three environmentally ubiquitous metals with robust evidence linking them to cardiovascular toxicity: lead, cadmium, and arsenic.
- Humans are exposed to lead, cadmium, and arsenic through contaminated air, water, soil, and food on a global scale. Low-level exposure to these contaminant metals is near-universal.
- These metals have no essential biological function. After exposure, lead and cadmium accumulate in the body, remaining in different storage compartments for decades. Arsenic is converted to methylated compounds and eliminated through the urine in a shorter timeframe.
- Experimental studies show that metal exposure alters biological pathways with shared roles in the regulation of cardiac and vascular functions, including vascular endothelial function, chronic inflammation, oxidative stress, epigenetic effects, and other cardiotoxic effects.
- Lead, cadmium, and arsenic are associated with pre-clinical measures of atherosclerosis including carotid plaque formation, abnormalities of the electrocardiogram and heart rate variability, as well as measures of cardiac geometry and function in human populations.
- In prospective cohort studies across diverse populations, and systematic reviews of those studies, lead, cadmium, and arsenic exposure independently contribute to ischemic heart disease, stroke, and premature cardiovascular mortality with a dose-response relationship. There is also prospective evidence for an association of these metals with peripheral artery disease and possibly with heart failure.
- The epidemiological evidence is strengthened by the results of clinical trials showing that a chelating agent with a high affinity for lead and cadmium reduces cardiovascular events, in particular in patients with diabetes and a prior myocardial infarction or peripheral artery disease.
- Disadvantaged populations encounter greater exposure to toxic metals due to proximity to environmental hazards and poor enforcement of environmental regulations; addressing metal exposures in this population may provide a strategy to reduce cardiovascular disease disparities.
- A multi-pronged approach to environmental cardiology that includes the measurement of metals through environmental monitoring and biomonitoring; mitigation and control of sources of exposure; and clinical interventions that remove metals or attenuate their effects may lead to improved cardiovascular health.
Citation
Lamas GA, Bhatnagar A, Jones MR, Mann KK, Nasir K, Tellez-Plaza M, Ujueta F, Navas-Acien A; on behalf of the American Heart Association Council on Epidemiology and Prevention; Council on Cardiovascular and Stroke Nursing; Council on Lifestyle and Cardiometabolic Health; Council on Peripheral Vascular Disease; and Council on the Kidney in Cardiovascular Disease on behalf of the American Heart Association. Contaminant metals as cardiovascular risk factors: a scientific statement from the American Heart Association. J Am Heart Assoc. 2023;12:e028489. DOI: 10.1161/JAHA.123.029852