Air Pollution and Inflammation (Interleukin-6, C-Reactive Protein, Fibrinogen) in Myocardial Infarction Survivors

Abstract

BackgroundNumerous studies have found that ambient air pollution has been associated with cardiovascular disease exacerbation.ObjectivesGiven previous findings, we hypothesized that particulate air pollution might induce systemic inflammation in myocardial infarction (MI) survivors, contributing to an increased vulnerability to elevated concentrations of ambient particles.MethodsA prospective longitudinal study of 1,003 MI survivors was performed in six European cities between May 2003 and July 2004. We compared repeated measurements of interleukin 6 (IL-6), fibrinogen, and C-reactive protein (CRP) with concurrent levels of air pollution. We collected hourly data on particle number concentrations (PNC), mass concentrations of particulate matter (PM) < 10 μm (PM10) and < 2.5 μm (PM2.5), gaseous pollutants, and meteorologic data at central monitoring sites in each city. City-specific confounder models were built for each blood marker separately, adjusting for meteorology and time-varying and time-invariant covariates. Data were analyzed with mixed-effects models.ResultsPooled results show an increase in IL-6 when concentrations of PNC were elevated 12–17 hr before blood withdrawal [percent change of geometric mean, 2.7; 95% confidence interval (CI), 1.0–4.6]. Five day cumulative exposure to PM10 was associated with increased fibrinogen concentrations (percent change of arithmetic mean, 0.6; 95% CI, 0.1–1.1). Results remained stable for smokers, diabetics, and patients with heart failure. No consistent associations were found for CRP.ConclusionsResults indicate an immediate response to PNC on the IL-6 level, possibly leading to the production of acute-phase proteins, as seen in increased fibrinogen levels. This might provide a link between air pollution and adverse cardiac events.

Air Pollution Exposures and Circulating Biomarkers of Effect in a Susceptible Population: Clues to Potential Causal Component mixtures and mechanisms

“…Our results are largely consistent with recent repeated measures studies showing associa tions between ambient air pollution and bio markers of systemic inflammation in healthy young adults (Chuang et al 2007) and sus ceptible subjects with CAD (Dubowsky et al 2006;Rückerl et al 2006Rückerl et al , 2007a2007b;Yue et al 2007). We extended these previous find ings with data from intensive home exposure assessments and modeling that provided clues to potentially causal pollutant components.…”

Health effects of a subway environment in healthy volunteers

“…The findings are supported by a study in London of .6,000 office workers which showed that increased levels of urban PM10 correlated with increased levels of plasma fibrinogen [25]. A prospective longitudinal study of .1,000 survivors of myocardial infarction showed similar results, with a correlation between particle number concentration and blood IL-6 levels [26]. In our present study, we did not detect any significant release of inflammatory cytokines after the subway exposure.…”

Tracheal instillation of urban PM2.5 suspension promotes acute cardiac polarization changes in rats

“…Epidemiological studies support the evidence that these alterations occur within a short period of time (24 h) and may increase the risk of arrhythmia development and sudden cardiac death. It is interesting to note that the time course of the ECG alterations in our healthy rats (2 h) was within the same time window as observed in clinical studies on patients with portable defibrillators or survivors of myocardial infarction (36,37). Peters et al (26) showed that patients with implanted cardioverter defibrillators experienced potentially life-threatening arrhythmias shortly after an 18 μg/m 3 increase in air PM 2.5 concentration.…”