Table 4.
Effect estimates (with 95%-confidence intervals) of particulate air pollution on heart rate variability parameters per interquartile range increase in the respective pollutant.
| PM2.5 | UFP | EC | OC | ||
|---|---|---|---|---|---|
| Hours before recording | |||||
| 5 minutes of spontaneous breathing in supine position | HFn | %-change of the arithmetic mean per increase in IQR pollutant (95%-CI) | |||
| 0 - 23 h | -3.6 (-11.6;4.2) | -2.2 (-10.8;6.3) | -5.1 (-12.6;2.4) | -9.9* (-19.2;-0.6) | |
| 24 - 47 h | 0.0 (-7.0;7.1) | 2.1 (-7.1;6.3) | -1.0 (-8.3;6.3) | -2.7 (-11.7;6.4) | |
| RMSSD | %-change of the geometric mean per increase in IQR pollutant (95%-CI) | ||||
| 0 - 23 h | -3.5 (-8.9;2.2) | -0.4 (-6.5;6.0) | -7.2** (-12.0;-2.1) | -8.0* (-14.0;-1.7) | |
| 24 - 47 h | -0.7 (-5.8;4.7) | 0.9 (-5.8;8.0) | -2.9 (-7.8;2.3) | -2.5 (-8.5;4.0) | |
| 24-hour recordings | RMSSD | %-change of the geometric mean per increase in IQR pollutant (95%-CI) | |||
| concurrent | -2.5 (-8.9;4.3) | 1.9 (-4.1;8.4) | -2.9 (-8.0;2.4) | -1.7 (-8.2;5.3) | |
| 0 - 23 h | -3.7 (-10.6;3.8) | 2.3 (-4.3;9.3) | -2.7 (-8.4;3.3) | -1.3 (-8.1;6.1) | |
| 24 - 47 h | -6.0 (-12.6;1.1) | -2.1 (-8.8;5.2) | -5.5* (-10.7;-0.1) | -5.8 (-12.1;0.9) | |
| pNN50 | %-change of the arithmetic mean per increase in IQR pollutant (95%-CI) | ||||
| concurrent | 0.6 (-14.9;16.1) | 5.5 (-8.4;19.3) | -4.7 (-17.1;7.6) | -5.9 (-22.0;10.2) | |
| 0 - 23 h | -6.4 (-23.1;10.2) | 1.6 (-13.5;16.7) | -9.6 (-23.0;3.9) | -14.5 (-30.3;1.2) | |
| 24 - 47 h | -16.0 (-32.4;0.4) | -7.5 (-23.8;8.8) | -13.8* (26.6;-1.1) | -17.5* (-33.0;-2.1) | |
| DC | %-change of the arithmetic mean per increase in IQR pollutant (95%-CI) | ||||
| concurrent | -6.4 (-13.1;0.3) | -0.8 (-7.1;5.4) | -9.1** (-15.4;-2.8) | -11.5** (-19.4;-3.6) | |
| 0 - 23 h | -9.9* (-17.4;-2.3) | -3.0 (-9.6;3.6) | -11.5** (-18.1;-4.9) | -14.2** (-22.2;-6.2) | |
| 24 - 47 h | -11.4** (-19.4;-3.7) | -5.6 (-13.2;2.0) | -10.4** (-17.3;-3.5) | -11.4** (-19.4;-3.4) | |
PM2.5: mass concentration of particles < 2.5 μm diameter; UFP: number concentration of particles between 0.01 and 0.1 μm diameter; EC, OC: elemental and organic carbon; HFn: normalized high-frequency; IQR: interquartile range; CI: confidence interval; RMSSD: square root of the mean square of successive differences of normal-to-normal (NN) intervals, pNN50: percentage of adjacent NN intervals which differ more than 50 ms, DC: deceleration capacity.
* p < 0.05 (significant), ** p < 0.01 (highly significant).