Title: Early Cardiovascular Risk in E-cigarette Users: the Potential Role of Metals.
Authors: Navas-Acien, Ana; Martinez-Morata, Irene; Hilpert, Markus; Rule, Ana; Shimbo, Daichi; LoIacono, Nancy J
Published In Curr Environ Health Rep, (2020 12)
Abstract: PURPOSE OF REVIEW: Electronic cigarettes (e-cigs) are a source of metals. Epidemiologic and experimental evidence support that metals are toxic to the cardiovascular system. Little is known, however, about the role that e-cig metals may play as toxicants for the possible cardiovascular effects of e-cig use. The goal of this narrative review is to summarize the evidence on e-cig use and metal exposure and on e-cig use and cardiovascular toxicity and discuss the research needs. RECENT FINDINGS: In vitro studies show cytotoxicity and increased oxidative stress in myocardial cells and vascular endothelial cells exposed to e-liquids and e-cig aerosols, with effects partially reversed with antioxidant treatment. There is some evidence that the heating coil plays a role in cell toxicity. Mice exposed to e-cigs for several weeks showed higher levels of oxidative stress, inflammation, platelet activation, and thrombogenesis. Cross-over clinical experiments show e-cig use alters nitric oxide-mediated flow-mediated dilation, endothelial progenitor cells, and arterial stiffness. Cross-sectional evidence from large nationally representative samples in the USA support that e-cig use is associated with self-reported myocardial infarction. Smaller studies found associations of e-cig use with higher oxidized low-density protein and heart variability compared to healthy controls. Numerous studies have measured elevated levels of toxic metals in e-cig aerosols including lead, nickel, chromium, and manganese. Arsenic has been measured in some e-liquids. Several of these metals are well known to be cardiotoxic. Numerous studies show that e-cigs are a source of cardiotoxic metals. Experimental studies (in vitro, in vivo, and clinical studies) show acute toxicity of e-cigs to the vascular system. Studies of long-term toxicity in animals and humans are missing. Longitudinal studies with repeated measures of metal exposure and subclinical cardiovascular outcomes (e.g., coronary artery calcification) could contribute to determine the long-term cardiovascular effects of e-cigs and the potential role of metals in those effects.
PubMed ID: 33242201
MeSH Terms: Animals; Cardiotoxins/adverse effects*; Cardiovascular Diseases/chemically induced*; Cardiovascular Diseases/pathology; Cardiovascular Diseases/physiopathology; Electronic Nicotine Delivery Systems*; Endothelial Cells/drug effects; Heart Disease Risk Factors; Humans; Inflammation; Metals/adverse effects*; Oxidative Stress/drug effects; Vaping/adverse effects*; Vaping/pathology; Vaping/physiopathology