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

Environ Health Perspect. 2007 Jul;115(7):1072-80. doi: 10.1289/ehp.10021.

Abstract

Background: Numerous studies have found that ambient air pollution has been associated with cardiovascular disease exacerbation.

Objectives: Given 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.

Methods: A 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 microm (PM(10)) and < 2.5 microm (PM(2.5)), 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.

Results: Pooled 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 PM(10) 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.

Conclusions: Results 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollution*
  • C-Reactive Protein / metabolism*
  • Fibrinogen / metabolism*
  • Humans
  • Inflammation / chemically induced*
  • Interleukin-6 / blood*
  • Myocardial Infarction / blood*

Substances

  • Interleukin-6
  • Fibrinogen
  • C-Reactive Protein