Cadmium, a common environmental pollutant, has been identified as a novel independent risk factor for early atherosclerosis, according to a study published in the latest issue of Atherosclerosis, Thrombosis and Vascular Surgery.
Barbara Messner from the Department of Cardiac Surgery, Innsbruck Medical University, Austria, and colleagues, carried out the research in young healthy women (n=195) of the Atherosclerosis Risk factors in Female Youngsters (ARFY) study. They noted that cadmium levels in these women were associated with the thickening of the vessel wall (intima-media thickness exceeding the 90th percentile of distribution) due to early atherosclerosis (multivariable odds ratio=1.6; P=0.016). Animal studies also yielded similar results with cadmium-fed ApoE knockout mice, in which a significantly higher aortic plaque surface was produced when compared to controls (P<0.004). Cadmium, at physiological doses, was found to increase vascular permeability by up to 6 times in vitro by the following mechanisms:
â€¢ Impeding the endothelial cell proliferation
â€¢ Inciting a Bcl-xL inhibitable and caspase-independent form of cell death 72 hours after inducing cadmium exposure.
These events were preceded by cadmium-induced DNA damage. Researchers also noted that zinc was found to be protective against the damaging effects of cadmium, both in human and in vitro studies.
Cadmium is a toxic heavy metal, having several deleterious effects on human health. Apart from smokers, certain industrial workers, such as makers of alloys, batteries, cadmium vapor lamps, glass, etc., are at an increased risk of chronic cadmium exposure and toxicity. The chief effects of the metal are as follows:
â€¢ Renal tubular and glomerular damage, and reduced glomerular filtration rate (manifested as proteinuria), ultimately leading to renal failure
â€¢ Etiopathogenesis of peripheral artery disease in smokers
â€¢ Diminished pulmonary function with obstructive changes
â€¢ Osteomalacia and osteoporosis leading to pseudofractures, due to the direct effect on bone and secondary to renal dysfunction
â€¢ Carcinogenicity and increased mortality
Cadmium contamination has increased over the past century, especially in the developing countries, primarily because cadmium-containing products are dumped along with household waste and rarely re-cycled. With more and more ill-effects of the heavy metal being discovered, it is vital to outline measures to minimize exposure, and set strict guidelines for permitted levels of daily exposure.
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