Microplastics. a New Risk Factor for Atherosclerotic Cardiovascular Disease

ASCVD/CVD Risk Factors Plastics are a part of our day-to-day lives. Once plastic disintegrates, it generates microplastics, which are invisible to the human eye. So far, there is evidence that microplastics have been found in tissues of plants, animals, and human beings, but their role in the causality of diseases is not yet uncovered. Atherosclerosis results from inflammation and fat deposition in the arteries that lead to plaque formation. This research aims to determine whether atherosclerosis could be brought about by or worsened by microplastics. Extensive search was performed across multiple databases, including PubMed, Scopus, Medline, and Embase. Keywords like 'MICROPLASTICS", "MICROPLASTICS AND ATHEROSCLEROSIS", "ATHEROSCLEROSIS", "NANOPLASTICS", "NANOPLASTICS AND ATHEROSCLEROSIS", "MICROPLASTICS AND INFLAMMATION", "MICROPLASTICS AND ENDOTHELIAL DYSFUNCTION”, etc. were used to search. Articles were chosen based on their relevancy and recency. After an extensive search, 58 articles passed the criteria and were chosen to be a part of the study. 1. Microplastics are ubiquitous, and they enter the body by three major routes - inhalation, ingestion and direct skin contact. 2. Microplastics affect the pathogenesis of atherosclerosis: a. They induce lipid accumulation in the cytoplasm, predisposing to foam cell formation. Microplastics and nanoplastics up-regulate the scavenger receptor - MARCO- causing LDL accumulation and worsening inflammation. b. Microplastics up-regulate ICAM-1, VCAM -1, TNF-α expression, causing enhanced adherence, transendothelial migration of inflammatory cells, and inflammation. c. Microplastics cause phenotype switching of vascular smooth muscle cells, which is a key pathological event in the formation of an atheroma. d. Microplastics accumulate in the formed atheroma plaque and harbour a worse fate as compared to plaques without microplastics. Microplastics enter the body via three major routes- food, air, or by skin contact. In the cardiovascular system, they are known to cause free radical damage and cardiac fibrosis. Specific to atherogenesis, they affect every step. They predispose to dyslipidemia, they cause endothelial dysfunction and inflammation, and they additionally create a procoagulant environment. microplastics cause vascular smooth muscle cells phenotype switching and are shown to accumulate in the plaque and accelerate its growth. With the given information, one can infer that microplastic exposure has a detrimental effect on cardiovascular health.