Ambient particulate air pollution, heart rate variability, and blood markers of inflammation in a panel of elderly subjects

Environ Health Perspect. 2004 Mar;112(3):339-45. doi: 10.1289/ehp.6588.


Epidemiologic studies report associations between particulate air pollution and cardiopulmonary morbidity and mortality. Although the underlying pathophysiologic mechanisms remain unclear, it has been hypothesized that altered autonomic function and pulmonary/systemic inflammation may play a role. In this study we explored the effects of air pollution on autonomic function measured by changes in heart rate variability (HRV) and blood markers of inflammation in a panel of 88 elderly subjects from three communities along the Wasatch Front in Utah. Subjects participated in multiple sessions of 24-hr ambulatory electrocardiographic monitoring and blood tests. Regression analysis was used to evaluate associations between fine particulate matter [aerodynamic diameter less than or equal to 2.5 microm (PM2.5)] and HRV, C-reactive protein (CRP), blood cell counts, and whole blood viscosity. A 100- microg/m3 increase in PM2.5 was associated with approximately a 35 (SE = 8)-msec decline in standard deviation of all normal R-R intervals (SDNN, a measure of overall HRV); a 42 (SE = 11)-msec decline in square root of the mean of the squared differences between adjacent normal R-R intervals (r-MSSD, an estimate of short-term components of HRV); and a 0.81 (SE = 0.17)-mg/dL increase in CRP. The PM2.5-HRV associations were reasonably consistent and statistically robust, but the CRP association dropped to 0.19 (SE = 0.10) after excluding the most influential subject. PM2.5 was not significantly associated with white or red blood cell counts, platelets, or whole-blood viscosity. Most short-term variability in temporal deviations of HRV and CRP was not explained by PM2.5; however, the small statistically significant associations that were observed suggest that exposure to PM2.5 may be one of multiple factors that influence HRV and CRP.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging*
  • Air Pollutants / poisoning*
  • Biomarkers / analysis
  • Blood Cell Count
  • C-Reactive Protein / analysis
  • Cross-Sectional Studies
  • Environmental Exposure*
  • Female
  • Heart Rate*
  • Humans
  • Inflammation*
  • Male
  • Middle Aged
  • Particle Size
  • Regression Analysis


  • Air Pollutants
  • Biomarkers
  • C-Reactive Protein