We examined the association between ambient air pollution levels and heart rate variability (HRV) in a panel study of 32 subjects.Methods:
We used linear mixed models to analyze the effects of fine particles (PM2.5), sulfate (SO42−), elemental carbon (EC), and gases on log-transformed standard deviation of normal RR intervals (SDNN), mean square of differences between adjacent RR intervals (r-MSSD), and high- and low-frequency power (HF, LF).Results:
An interquartile range (IQR) increase of 5.1 μg/m3 in SO42− on the previous day was associated with a decrease of −3.3% SDNN (95% confidence = −6.0% to −0.5%), −5.6% r-MSSD (−10.7% to −0.2%), and −10.3% HF (−19.5% to −0.1%). Associations with total PM2.5 were similar. HRV was not associated with EC, NO2, SO2, or O3.Conclusion:
In addition to traffic-related particles, elevated levels of sulfate particles may also adversely affect autonomic function.