Table 4.
Effect of SWS deprivation on objective and subjective sleep parameters
| Objective (PSG) sleep measures | Intervention group | Baseline | N1 | N2 | N3 |
|---|---|---|---|---|---|
| Total sleep time (min) | Control | 417.2 (32.2) 52 | −5.8 (34.4) 49 | 2.5 (31.2) 50 | −7.8 (35.5) 52 |
| Disruption | 409.6 (43.8) 51 | −18.9 (57.1) 50 | 2.3 (52.0) 50 | 23.7 (41.5) 50*** | |
| Latency to persistent sleep (min) | Control | 15.5 (11.5) | 4.9 (19.9) | 3.0 (16.9) | 13.4 (30.5) |
| Disruption | 22.5 (22.8) | 22.8 (49.4)* | 2.5 (34.6) | −6.1 (20.7)*** | |
| PSG awakenings (number) | Control | 24.0 (9.8) | −1.5 (8.8) | −1.5 (7.6) | −1.7 (9.4) |
| Disruption | 22.6 (8.0) | 9.7 (11.3)*** | 10.5 (9.7)*** | −3.9 (9.0) | |
| Wake after sleep onset (min) | Control | 43.2 (30.5) | 0.7 (29.7) | −5.8 (28.1) | −1.1 (27.6) |
| Disruption | 46.1 (39.3) | 8.8 (40.3) | −3.6 (33.2) | −17.9 (33.7)** | |
| Stage 1 (min) | Control | 26.9 (12.4) | −2.5 (9.9) | −0.9 (10.3) | −1.3 (11.7) |
| Disruption | 29.1 (13.8) | 9.1 (16.2)*** | 3.6 (14.6)* | −7.9 (15.1)* | |
| Stage 2 (min) | Control | 206.4 (31.0) | −8.6 (29.5) | −6.2 (25.3) | −12.8 (29.6) |
| Disruption | 202.5 (31.3) | 26.9 (43.4)*** | 25.5 (36.7)*** | −7.9 (34.6) | |
| Stage 3 (min) | Control | 42.0 (14.6) | −1.3 (14.8) | −2.5 (14.6) | −5.2 (14.4) |
| Disruption | 42.6 (21.0) | −5.3 (22.2) | 8.2 (28.7)* | −1.4 (20.4) | |
| Stage 4 (min) | Control | 58.6 (31.6) | 1.5 (14.9) | 0.7 (16.2) | 0.8 (15.2) |
| Disruption | 53.0 (27.4) | −45.4 (27.9)*** | −41.9 (21.5)*** | 22.4 (23.1)*** | |
| Slow wave sleep (min) | Control | 100.6 (34.9) | 0.2 (20.0) | −1.85 (21.8) | −4.4 (21.1) |
| Disruption | 95.6 (36.6) | −50.7 (32.1)*** | −33.7 (28.8)*** | 20.9 (27.1)*** | |
| SWA (Baseline: μV2, N1-3: % from baseline) | Control | 2456 (1305) 52 | −0.1 (15.8) 47 | 1.2 (17.7) 49 | 0.9 (17.5) 52 |
| Disruption | 2368 (1280) 51 | -20.3 (21.7) 50*** | −10.2 (25.3) 48** | 24.2 (28.5) 50 *** | |
| REM sleep (min) | Control | 83.3 (21.1) | 5.0 (23.5) | 11.4 (23.2) | 10.6 (22.9) |
| Disruption | 82.3 (22.7) | −4.3 (25.9) | 6.9 (31.3) | 18.6 (31.8) | |
| Subjective sleep measures | |||||
| Total sleep time (h) | Control | 7.4 (0.6) 56 | −0.0 (0.7) 54 | 0.1 (0.7) 56 | −0.1 (0.8) 56 |
| Disruption | 7.0 (1.1) 54 | −0.6 (1.5) 53* | −0.4 (1.5) 54 P = 0.054 | 0.6 (1.1) 54*** | |
| Latency to sleep onset (min) | Control | 29.5 (80.2) | −14.0 (82.2) | −15.5 (79.5) | −5.4 (84.2) |
| Disruption | 27.2 (35.1) | 0.6 (38.7) | −9.7 (44.4) | −15.3 (36.4) | |
| Number of awakenings | Control | 2.3 (1.8) | 0.6 (2.2) | 0.0 (2.4) | −0.4 (2.1) |
| Disruption | 2.6 (1.9) | 7.3 (10.9)*** | 5.8 (8.7)*** | −1.4 (1.7)** | |
| Subjective duration of awakenings (min) | Control | 35.9 (87.7) | 8.8 (109.5) | −10.3 (112.2) | −13.6 (94.8) |
| Disruption | 26.7 (33.3) | 44.8 (89.5) | 45.7 (181.7) P = 0.05 | 2.1 (98.2) | |
| Quality of sleep (mm; more is bad) | Control | 43.9 (20.8) | −2.5 (24.1) | −2.7 (22.9) | −1.2 (23.0) |
| Disruption | 53.8 (20.7) | 13.1 (28.7)** | 6.4 (30.8) | −27.5 (32.7)*** | |
| Refreshed upon awakening (mm; more is better) | Control | 57.7 (19.9) | 1.4 (23.7) | 2.9 (23.3) | 0.8 (23.4) |
| Disruption | 51.0 (21.0) | −13.1 (27.7)** | −3.6 (28.0) | 14.6 (28.1)** | |
N1-N3 data are expressed as deviation from baseline and the contrast between SWS Disruption and SWS Control was computed for these difference scores.
*
P < 0.05;
**
P < 0.01;
***
P < 0.001. Mean (SD) N. Please note that number of subjects contributing to the mean are indicated only once for the visually scored PSG measures (see TST), SWA and subjective measures (TST).