Table 2. Statistical values of the features from the PRV analysis.
| Features | Time domain | Frequency domain | |||||
|---|---|---|---|---|---|---|---|
| PP | SDPP | rMSSD | LF | HF | LF/HF | ||
| G1 | Normal | 78.4 ± 3.3 | 1,113.0 ± 49.1 | 1,557.0 ± 69.4 | 3.1 ± 11.3 | 16.8 ± 49.4 | 0.9 ± 0.4 |
| OSA | 88.5 ± 20.3 | 1,269.0 ± 248.5 | 1,799.0 ± 403.3 | 3.6 ± 15.8 | 7.1 ± 13.8 | 0.5 ± 0.3 | |
| P value | 0.474 | 0.487 | 0.487 | 0.487 | 0.487 | 0.487 | |
| G2 | Normal | 118.0 ± 4.0 | 1,660.0 ± 43.0 | 2,354.0 ± 61.0 | 6.4 ± 38.6 | 4.0 ± 12.9 | 0.9 ± 0.3 |
| OSA | 99.4 ± 21.9 | 1,453.0 ± 292.6 | 2,060.0 ± 414.8 | 4.4 ± 21.6 | 8.6 ± 28.3 | 0.6 ± 0.4 | |
| P value | 0.491 | 0.493 | 0.493 | 0.493 | 0.493 | 0.493 | |
| G3 | Normal | 85.1 ± 10.0 | 1,125.0 ± 149.0 | 1,596.0 ± 211.2 | 22.5 ± 445.0 | 48.5 ± 105.2 | 1.2 ± 0.5 |
| OSA | 101.2 ± 25.6 | 1,372.0 ± 379.9 | 1,945.0 ± 538.8 | 5.0 ± 42.0 | 8.6 ± 93.6 | 0.7 ± 0.3 | |
| P value | 0.542 | 0.494 | 0.494 | 0.494 | 0.494 | 0.494 | |
| Total | Normal | 74.2 ± 11.2 | 1,113.0 ± 114.2 | 1,577.0 ± 162.6 | 47.2 ± 671.0 | 101.5 ± 1,611.1 | 0.8 ± 0.7 |
| OSA | 99.4 ± 24.1 | 1,392.0 ± 346.4 | 1,974.0 ± 491.1 | 4.7 ± 33.9 | 8.5 ± 71.1 | 0.6 ± 0.4 | |
| P value | 0.616 | 0.664 | 0.665 | 0.544 | 0.620 | 0.573 | |
Data are shown as mean ± SD.
G1 = mild (AHI > 5), G2 = moderate (AHI > 15), G3 = severe (AHI > 30), AHI = apnea-hypopnea index, PRV = pulse rate variability, OSA = obstructive sleep apnea, PP = pulse-to-pulse interval, SDPP = standard deviation of the pulse-to-pulse interval, rMSSD = root mean square of successive differences, LF = low-frequency, HF = high-frequency, SD = standard deviation.