Ambient Particulate Matter, C-Reactive Protein, and Coronary Artery Disease

Abstract

This article is a review of the scientific literature with respect to fine particulate matter (PM), 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, and coronary artery disease (CAD). The association between air pollution and respiratory diseases has been extensively investigated for decades; however, the role of air pollution in exacerbating heart disease has only recently become a focus of attention. It has been shown that for every 10-μg/m³ increase in fine PM in the air, there appears to be a 2.1% increase in the number of deaths related to ischemic heart disease. PM has been linked to increased levels of systemic inflammation biomarkers such as C-reactive proteins (CRP). Daily variation of ambient pollution is correlated with rises and falls in CRP levels. Increased CRP levels have been associated with increased morbidity and mortality in individuals with CAD. Seventy-five percent of patients with elevated CRP levels have reportedly experienced a major cardiac event despite low-density lipoproteins (LDL) levels that were below the threshold recommended for pharmacological intervention. HMG CoA reductase inhibitors (statins) have been shown to cause a reduction in coronary events by lowering LDL levels. However, recently it has been shown that statins have the effect of lowering CRP levels. This may explain why individuals with normal lipid levels may benefit from statin therapy. Ambient PM exposure levels and its effects on CRP are risk factors associated with coronary events and should be considered as a target for the treatment of CAD.