It is still unknown whether the associations between particulate matter (PM) and heart rate variability (HRV) differ by particle sizes with aerodynamic diameters between 0.3 μm and 1.0 μm (PM0.3-1.0), between 1.0 μm and 2.5 μm (PM1.0-2.5), and between 2.5 μm and 10 μm (PM2.5-10). We measured electrocardiographics and PM exposures in 10 patients with coronary heart disease and 16 patients with either prehypertension or hypertension. The outcome variables were standard deviation of all normal-to-normal (NN) intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD), low frequency (LF; 0.04-0.15 Hz), high frequency (HF; 0.15-0.40 Hz), and LF:HF ratio for HRV. The pollution variables were mass concentrations of PM0.3-1.0, PM1.0-2.5, and PM2.5-10. We used linear mixed-effects models to examine the association between PM exposures and log10-transformed HRV indices, adjusting for key personal and environmental attributes. We found that PM0.3-1.0 exposures at 1- to 4-hr moving averages were associated with SDNN and r-MSSD in both cardiac and hypertensive patients. For an interquartile increase in PM0.3-1.0, there were 1.49-4.88% decreases in SDNN and 2.73-8.25% decreases in r-MSSD. PM0.3-1.0 exposures were also associated with decreases in LF and HF for hypertensive patients at 1- to 3-hr moving averages except for cardiac patients at moving averages of 2 or 3 hr. By contrast, we found that HRV was not associated with either PM1.0-2.5 or PM2.5-10. HRV reduction in susceptible population was associated with PM0.3-1.0 but was not associated with either PM1.0-2.5 or PM2.5-10.
|頁（從 - 到）||1693-1697|
|期刊||Environmental Health Perspectives|
|出版狀態||已發佈 - 12月 2005|
ASJC Scopus subject areas
- 環境科學 (全部)