TABLE 2.
Polysomnography characteristics of participants stratified by blood pressure dipping status.
| Total (n = 51) | Dippers (n = 11) | Non-dippers (n = 40) | |
| Sleep efficiency, % | 79.8 ± 13.7 | 76.8 ± 14.7 | 80.7 ± 13.5 |
| Total sleep time, h | 6.1 ± 1.6 | 5.6 ± 2.1 | 6.2 ± 1.5 |
| Sleep stage: | |||
| %NREM 1 | 19.2 ± 10.6 | 19.4 ± 10.1 | 19.1 ± 10.9 |
| %NREM 2 | 47.1 ± 9.1 | 47.3 ± 6.7 | 47.1 ± 9.8 |
| %NREM 3 | 16.8 ± 11.4 | 17.7 ± 12.5 | 16.5 ± 11.2 |
| %REM | 16.9 ± 7.6 | 15.7 ± 8.1 | 17.2 ± 7.6 |
| Sleep onset latency, min | 16.2 ± 25.9 | 9.8 ± 11.5 | 18.0 ± 28.6 |
| WASO, min | 72.1 ± 56.9 | 76.8 ± 50.0 | 70.7 ± 59.3 |
| REM latency, min | 100.5 ± 53.7 | 117.3 ± 68.3 | 95.4 ± 48.6 |
| Microarousal index, /h | 40.5 ± 19.7 | 41.3 ± 17.9 | 40.2 ± 20.4 |
| Total sleep time in supine, % | 20.0 ± 23.3 | 13.8 ± 14.4 | 21.8 ± 25.1 |
| AHI, events/h | 27.7 ± 26.4 | 25.3 ± 22.3 | 28.3 ± 27.6 |
| AI, events/h | 2.6 ± 7.6 | 1.3 ± 2.7 | 3.0 ± 8.5 |
| HI, events/h | 25.1 ± 21.0 | 24.0 ± 20.0 | 25.3 ± 21.6 |
| REM-AHI, events/h | 42.6 ± 27.3 | 47.8 ± 35.1 | 41.0 ± 24.8 |
| NREM-AHI, events/h | 22.7 ± 26.5 | 22.9 ± 22.6 | 22.7 ± 27.8 |
| Supine-AHI, events/h | 35.3 ± 26.2 | 36.2 ± 24.0 | 35.1 ± 27.2 |
| Non-supine AHI, events/h | 26.1 ± 29.6 | 24.2 ± 22.4 | 26.6 ± 31.6 |
| Respiratory arousal index, events/h | 20.1 ± 19.1 | 19.8 ± 21.2 | 20.2 ± 18.8 |
| 4% ODI, events/h | 9.9 ± 22.2 | 5.2 ± 6.3 | 11.1 ± 24.5 |
| Mean SpO2, % | 95.7 ± 1.8 | 95.9 ± 1.8 | 95.7 ± 1.9 |
| Nadir SpO2, % | 87.3 ± 6.5 | 85.9 ± 7.9 | 87.7 ± 6.2 |
| TST < 90%, % | 2.0 ± 7.9 | 0.6 ± 1.5 | 2.4 ± 8.8 |
Values are presented in means ± SD. WASO, wake after sleep onset; REM, rapid eye movement; NREM, non-rapid eye movement; AHI, apnea-hypopnea index; AI, apnea index; HI, hypopnea index; REM-AHI, apnea-hypopnea index during REM sleep; NREM-AHI, apnea-hypopnea index during NREM sleep; Supine-AHI, apnea-hypopnea index during supine position; Non-supine AHI, apnea-hypopnea index during non-supine position; 4%ODI, 4% oxygen desaturation index; SpO2, oxygen saturation during sleep; TST < 90%, total sleep time with oxygen saturation < 90%.