Effects of Air Pollution on Heart Rate Variability: The VA Normative Aging Study

Abstract

Reduced heart rate variability (HRV), a marker of poor cardiac autonomic function, has been associated with air pollution, especially fine particulate matter [< 2.5 μm in aerodynamic diameter (PM2.5)]. We examined the relationship between HRV [standard deviation of normal-to-normal intervals (SDNN), power in high frequency (HF) and low frequency (LF), and LF:HF ratio] and ambient air pollutants in 497 men from the Normative Aging Study in greater Boston, Massachusetts, seen between November 2000 and October 2003. We examined 4-hr, 24-hr, and 48-hr moving averages of air pollution (PM2.5, particle number concentration, black carbon, ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide). Controlling for potential confounders, HF decreased 20.8% [95% confidence interval (CI), 4.6–34.2%] and LF:HF ratio increased 18.6% (95% CI, 4.1–35.2%) per SD (8 μg/m3) increase in 48-hr PM2.5. LF was reduced by 11.5% (95% CI, 0.4–21.3%) per SD (13 ppb) increment in 4-hr O3. The associations between HRV and PM2.5 and O3 were stronger in people with ischemic heart disease (IHD) and hypertension. The associations observed between SDNN and LF and PM2.5 were stronger in people with diabetes. People using calcium-channel blockers and beta-blockers had lower associations between O3 and PM2.5 with LF. No effect modification by other cardiac medications was found. Exposures to PM2.5 and O3 are associated with decreased HRV, and history of IHD, hypertension, and diabetes may confer susceptibility to autonomic dysfunction by air pollution.

Ambient fine particles modify heart rate variability in young healthy adults

“…All of them found that an increase in PM 2.5 or in PM 10 , alone or combined with other pollutants like ozone, were associated with a reduction of the SDNN and of the rMSSD, only one study informed an increase of this last index (Gold et al, 2000). Studies in which frequency domain indexes were used also found this association, particularly of the HF of a parasympathetic-related index (Liao et al, 1999;Holguı´n et al, 2003;Park et al, 2005).…”

“…Most air pollution research has measured the exposure with fix monitors, in some cases data were taken from the environmental monitor network, which is known to be a good estimate but may be altered by weather conditions such as wind, rain or RH (Pope et al, 1999, Gold et al, 2000, Park et al, 2005. Other studies have used fixed indoor monitors (Liao et al, 1999;Holguı´n et al, 2003).…”

“…Recent studies that included elderly individuals with heart diseases in Baltimore, Boston and Mexico City suggest that PM 2.5 air pollution measured with ambient monitors was associated with a reduced HRV (Liao et al, 1999;Gold et al, 2000;Holguı´n et al, 2003;Park et al, 2005). The aim of this study was to test whether this association could also be observed in young healthy adults, using personal exposure monitors, at ambient levels currently observed in the Mexico City metropolitan area (MCMA).…”

Source location of air pollution and cardiac autonomic function: Trajectory cluster analysis for exposure assessment

“…In a previous community-based cross-sectional study, we reported that particulate matter o2.5 mm in aerodynamic diameter (PM 2.5 ), ozone (O 3 ), and BC were associated with reduced cardiac autonomic function, measured by HRV (Park et al, 2005). In this paper, we examine whether pollution originating in different locations has different associations with HRV using data from our previous study (Park et al, 2005) and from a trajectory cluster analysis.…”

“…In this paper, we examine whether pollution originating in different locations has different associations with HRV using data from our previous study (Park et al, 2005) and from a trajectory cluster analysis.…”