Micro and Nanoplastics and Cardiovascular Events – Recent Study

Use of plastics in daily life is currently on the increase and it is a well known pollutant in our water bodies like rivers, ponds, lakes and ocean. Plastics can be degraded into microplastics which are smaller than 5 mm and nanoplastics which are smaller than 1000 nanometer [1]. Microplastics and nanoparticles can trigger toxicologic effects in the body [2]. Both microplastics and nanoplastics can enter our body through ingestion, inhalation and even by topical exposure on the skin. According to a webpage from United States National Oceanic and Atmospheric Administration (NOAA), microbeads which are a type of microplastic are added as exfoliants to health and beauty products as well as some cleansers and even toothpastes! A study published in the New England Journal of Medicine has correlated the presence of micro and nano plastics in carotid atheromas to cardiovascular events [3].

Experimental studies have suggested that micro and nanoplastics promote oxidative stress, inflammation and apoptosis in endothelial and other vascular cells which could lead to impairment in cardiac function, myocardial fibrosis and endothelial dysfunction [4]. The NEJM study [3] was a prospective, multicenter observational study of patients undergoing carotid endarterectomy for asymptomatic carotid artery disease. Detailed analysis of the excised carotid plaques were carried out with pyrolysis-gas chromatography-mass spectrometry, stable isotope analysis, and electron microscopy. Inflammatory biomarkers were also estimated. Primary endpoint of the study was a composite of myocardial infarction, stroke, or death from any cause in those who had micro and nanoplastics in the carotid plaque. Comparison was with those who had no evidence of these plastics in the plaques.

Polyethylene was detected in carotid artery plaque of 150 patients among the 257 who completed the study. Initial number of patients enrolled was 304. Polyvinyl chloride was detected in plaques of 31 patients. Foreign particles were noted in plaque macrophages on electron microscopy. Patients who had micro and nanoplastics in atheroma were at a higher risk of the primary endpoint with a hazard ratio of 4.53. Mean follow up period in the study was about 34 months. One limitation mentioned in the paper attracted my attention. Even though good care was taken, they could not completely rule out laboratory contamination because of the ubiquitous presence of plastics everywhere! They suggested future studies with the use of clean rooms where there is no plastic in any form except the material under study.

References

1. Gigault J, Halle AT, Baudrimont M, Pascal PY, Gauffre F, Phi TL, El Hadri H, Grassl B, Reynaud S. Current opinion: What is a nanoplastic? Environ Pollut. 2018 Apr;235:1030-1034. doi: 10.1016/j.envpol.2018.01.024. Epub 2018 Jan 19. PMID: 29370948.
2. Vethaak AD, Legler J. Microplastics and human health. Science. 2021 Feb 12;371(6530):672-674. doi: 10.1126/science.abe5041. PMID: 33574197.
3. Marfella R, Prattichizzo F, Sardu C, Fulgenzi G, Graciotti L, Spadoni T, D’Onofrio N, Scisciola L, La Grotta R, Frigé C, Pellegrini V, Municinò M, Siniscalchi M, Spinetti F, Vigliotti G, Vecchione C, Carrizzo A, Accarino G, Squillante A, Spaziano G, Mirra D, Esposito R, Altieri S, Falco G, Fenti A, Galoppo S, Canzano S, Sasso FC, Matacchione G, Olivieri F, Ferraraccio F, Panarese I, Paolisso P, Barbato E, Lubritto C, Balestrieri ML, Mauro C, Caballero AE, Rajagopalan S, Ceriello A, D’Agostino B, Iovino P, Paolisso G. Microplastics and Nanoplastics in Atheromas and Cardiovascular Events. N Engl J Med. 2024 Mar 7;390(10):900-910. doi: 10.1056/NEJMoa2309822. PMID: 38446676.
4. Zhu X, Wang C, Duan X, Liang B, Genbo Xu E, Huang Z. Micro- and nanoplastics: A new cardiovascular risk factor? Environ Int. 2023 Jan;171:107662. doi: 10.1016/j.envint.2022.107662. Epub 2022 Nov 26. PMID: 36473237.