Association of air pollutants and genetic polymorphism on the initiation of atherosclerosis

The harmful effects of air pollution on atherosclerotic cardiovascular diseases (ACVD) are well-documented;[1] even short-term exposure to air pollutants is associated with cardiovascular disorder.[2,3] The underlying mechanisms have yet to be determined; pulmonary and systemic oxidative stress and inflammatory responses provoking endothelial dysfunction, disturbance of the platelet function, blood coagulability, and thrombosis are suggested to be the effects of air pollutants.[4,5] Some experimentalstudies have confirmed the possible effect of air pollutants on the blood vessel endothelium and in turn on increasing the risk of atherosclerosis.[6-8]Furthermore, the contribution of genetic factors in ACVD should be taken into account. Most of these genes participate in producing proteins that affect the progression of atherosclerosis or thrombosis. One of these proteins is thrombomodulin (TM), an endothelial cell membrane-bound glycoprotein, with its main physiological function being to bind thrombin.[9] On the other hand, increase in the level of blood coagulability is proposed as another underlying mechanism for air pollution-induced atherogenesis.[10] Exposure to ultrafine PM increases expression of the tissue factor (TF) in atherosclerotic lesions.[1,11] For the first time, we also found an independent association of air pollutants with the serum TF level in children and adolescents.[12] Considerable interest has been focused over the years on examining the importance of gene-environment interaction on ACVD.[1] There is a growing body of evidence about the start of the aforementioned effects of air pollutants on the process of atherosclerosis from early life,[13-15] and studying the effects of genetic-environment factors on early stages of atherosclerosis in early life can help identify the underlying mechanisms.The aim of this study was to determine the association of some genetic polymorphisms in the relationship of air pollutants, on the serum levels of TM and TF, in a population-based sample of children and adolescents. We selected the pediatric age group in this regard to reduce the impact of the confounding factors related to the process of aging and the accumulation of the ACVD risk factors