Acute effect of exposure on heart rate variability in healthy volunteers during rest (n=15)
| Filtered air | Diesel exhaust | Two-way ANOVA p value | |||||
| Baseline | 2 h | 6 h | Baseline | 2 h | 6 h | ||
| Heart rate (bpm) | 69±2 | 65±2 | 65±2 | 66±2 | 67±2 | 64±2 | 0.554 |
| NN interval (ms) | 889±32 | 934±28 | 937±30 | 920±26 | 915±29 | 952±36 | 0.542 |
| SDNN (ms) | 91±9 | 79±6 | 67±5 | 71±4 | 90±7 | 74±7 | 0.836 |
| RMSSD (ms) | 54±6 | 58±5 | 48±4 | 50±5 | 54±5 | 52±7 | 0.787 |
| PNN50 (%) | 27±4 | 33±4 | 26±4 | 29±5 | 31±4 | 29±6 | 0.600 |
| Triangular index | 19±1 | 17±1 | 14±1 | 15±1 | 18±1 | 14±1 | 0.141 |
| HF power (ms2) | 770±139 | 892±166 | 669±105 | 665±111 | 914±144 | 887±269 | 0.682 |
| LF power (ms2) | 3058±467 | 2130±273 | 1703±244 | 2143±334 | 2474±406 | 1591±247 | 0.346 |
| HFn (ms) | 22±3 | 29±3 | 28±3 | 24±3 | 26±2 | 30±4 | 0.827 |
| LFn (ms) | 76±3 | 68±3 | 70±3 | 74±3 | 71±2 | 68±4 | 0.915 |
| HF/LF ratio | 0.3±0.1 | 0.5±0.1 | 0.4±0.1 | 0.4±0.1 | 0.4±0.1 | 0.5±0.1 | 0.862 |
All variables are presented as mean±SEM.
Two-way ANOVA filtered air vs diesel exhaust at each time point.
HF, high frequency; HFn, normalised high frequency; LF, low frequency; LFn, normalised low frequency; PNN50, percentage of successive NN interval differences >50 ms; RMSSD, root mean square of successive NN interval differences; SDNN, SD of NN interval values.