Association Between Particulate Matter Pollution And The Risk Of Acute Coronaiy Syndrome

Background: Adverse effect of air pollution on human health is oneof the major concerns in current national and internationalclinical research. Especially, association between particalatematter (PM) pollution and acute coronary syndromes has attractedwidely attention from medical research, environmental agencies andsocial media. PM travels into respiratory system when inhaled. Thesmaller particles tend to penetrate into gas exchange regions, andthen pass through lung to damage other organs. PM also elevateslevels of fibrinogen and coagulation factors in plasma, induceswhole blood viscosity, and decreases concentration of hemoglobin.Consequently, presence of PM in blood circulation results adecrease of blood flow, reduces oxygen supply, aggravatesmyocardial ischemia, and is strongly associated with an increaseof incidence and mortality rates of acute coronary syndromes.However, damages caused by PM on cardiovascular system are thoughtto be predictable and reversible. Therefore, it is clinically andscientifically important to understand the effect of PM on acutecoronary syndromes risk. This will assist the design of treatmentstrategy to protect high-risk population through severe airpollution, with an aim to reduce mortality rate of acute coronary syndromes. This project is focused on investigating therelationship between PM and the risk of acute coronary syndromesin JiLin Province, Northeast China, during2011and2013period.It assesses the adverse effect of PM on the cardiovascular system,presents the potential mechanisms of PM damaging and also discussesthe possible solution of preventing acute coronary syndromesduring heavy polluted days.Participants and methods: This project collects3,497acutecoronary syndromes (ACS) cases admitted into China-Japan UnionHospital, JiLin University between January2011and December2013.It also includes412myocardial infarction (MI) cases, who havedetailed clinical information such as data from general blood tests,routine coagulation tests, liver function tests, and lipid levelsetc. The corresponding PM indexes are obtained from publisheddatabase of Ministry of Environmental Protection (The People’sRepublic of China). Data analysis and statistic modeling is carriedout in R. Quantitative traits are presented by mean±standarddivision, whereas the difference between case and control groupsis based on an unpaired t-test. The binary/categorical data isassessed by chi-squared test. The statistical significance usesa cut off of p<0.05.Results: This project revealed a positive association between PM index and inpatient rate of ACS, which was independent on patients’medical histories or patients’ ages. Moreover, comparing theinpatient rates of MI and non-MI cases found that PM index wastightly associated with the inpatient rate of MI cases, such asfor every unit increase of logarithmic transformed PM index, therisk of MI elevated by0.18fold (95%CI:1.05－1.33； p=0.004).In contrast, PM index had a greater effect on the inpatient riskof non-MI cases. For example, in non-MI cases, every unit increaseof logarithmic transformed PM index was linked to an increased riskof0.54fold（95%CI:1.11－2.13； p=0.01）。On the other hand,this project did not found any evidence to support a significanteffect of PM index on the age of ACS onset, although sub-groupanalysis showed that PM index was reversely associated with ACSage of onset, particular in the females（OR＝0.02；95%CI:0.001－0.25； p=0.003). Further, analyses of PM index in associationwith ACS clinical data revealed strong effects on MCV, hemoglobinconcentration and albumin level.Conclusion: This research replicated the positive associationbetween PM index and incidence of ACS. It also noted that airpollution could potentially reduce the age of onset of ACS and havesignificant impact on patients with medical history ofhypertension and/or diabetes. Moreover, observing the change of ACS clinical data such as MCV, hemoglobin concentration and albuminlevel during pollution days could potentially help in estimatingthe effect of PM index on the body system as well as predictingthe onset of ACS.