Exposure to Fine Particulate Matter Leads to Rapid Heart Rate Variability Changes

Abstract

Introduction: Heart Rate Variability (HRV) reflects the adaptability of the heart to internal and external stimuli. Reduced HRV is a predictor of post-infarction mortality. We previously found in road maintenance workers HRV-increases several hours after exposure to fine particulate matter (PM 2.5). This seemed to conflict with studies where PM-exposure acutely reduced HRV. We therefore assessed whether time from exposure to HRV-assessment could explain the differences observed. Methods: On five non-consecutive days, workers carried nephelometers providing 1-min-interval PM 2.5-exposure. Five-min HRV-intervals of SDNN (Standard Deviation of Normal to Normal beat intervals) and pNN50 (Percentage of the interval differences exceeding 50 ms) were extracted from 24-h electrocardiograms (ECGs). Following 60 min PM 2.5-exposure, changes in HRV-parameters were assessed during 120-min visually and by regression analysis with control for time at work, at home, and during the night using autoregressive integrating moving average (ARIMA) models to account for autocorrelation of the time-series. Additional controls included changing the time windows and including body mass index (BMI) and age in the models. Result: Pattern analysis of 12,669 data points showed high modulation of mean, standard deviation (SD), and time trend of HRV (SDNN and pNN50) at low, and much reduced modulation at high PM 2.5-exposures. The time trend following exposure was highly symmetrical, resembling a funnel plot. Regression analysis showed significant associations of decreasing SDNN and pNN50 (average, SD, and absolute value of time trend) with increasing PM 2.5-exposure, which remained significant when controlling for activity phases. Changing time windows did not change the pattern of response. Including BMI and age did not change the results. Conclusions: The reduced modulation of HRV following PM 2.5-exposure is striking. It suggests strong interference with homeostatic controls. Such an interference would represent a serious bodily burden, and could help explain acute cardiac events. In this model, the increase of HRV several hours later would reflect a recovery response.

Effects of Personal Exposures to Micro- and Nano-Particulate Matter, Black Carbon, Particle-Bound Polycyclic Aromatic Hydrocarbons, and Carbon Monoxide on Heart Rate Variability in a Panel of Healthy Older Subjects

“…Thus, the factor of the season was not included in the final model to increase statistical power. The literature review also found that many studies used the hourly moving average concentration of pollutants to observe their “cumulative” health effects, and the shortest one was usually the 1 h moving average concentration [29,30]. Therefore, this study selected 9 time scales (5 min average concentration, 1, 2, 3, 4, 5, 6, 7, and 8 h moving average concentration), and the R statistical software (version 2.10.1, R Foundation for Statistical Computing, Vienna, Austria) was used to model the personal exposures of nine time scales and HRVs with the GAMM.…”

Traffic-Related Particulate Matter and Cardiometabolic Syndrome: A Review

“…It has been reported to be modified by traffic-related PM 2.5 in both epidemiological and toxicological studies. In the study on 18 healthy male Swiss highway maintenance workers that was conducted by Riediker et al [31], a reduced standard deviation from normal to normal beat intervals (a marker of global autonomic activity) and the percentage of the interval differences exceeding 50 ms (a marker of parasympathetic activity) were observed after acute exposure to PM 2.5 , especially during the working hours along the highway. This result indicated a reduction in autonomic nervous activity that was induced by traffic-related PM [31,63].…”

“…In the study on 18 healthy male Swiss highway maintenance workers that was conducted by Riediker et al [31], a reduced standard deviation from normal to normal beat intervals (a marker of global autonomic activity) and the percentage of the interval differences exceeding 50 ms (a marker of parasympathetic activity) were observed after acute exposure to PM 2.5 , especially during the working hours along the highway. This result indicated a reduction in autonomic nervous activity that was induced by traffic-related PM [31,63]. Similarly, a toxicological study by Wagner et al [38] reported enhanced and prolonged cardiac depression, including decreased heart rate variability and blood pressure, induced by traffic-related PM 2.5 using a rat model.…”

Recreational physical activity and the problem of particulate matter air pollution

“…Direct penetration of smallest particles to bloodstream is also important. Endothelium dysfunction and vasoconstriction are among observed effects of this process (6,(11)(12).…”

“…Istotna jest także bezpośrednia penetracja najdrobniejszych frakcji pyłu do krwiobiegu, a udokumentowane efekty tego procesu obejmują m. in. dysfunkcję śródbłonka i skurcz naczyń (6,(11)(12).…”