Table 2.
Sleep structures among normal sleepers and insomnia patients
| Normal (n=17) | Paradoxical insomnia (n=19) | Psychophysiological insomnia (n=17) | P | |
|---|---|---|---|---|
| PSQI findings | ||||
| Total scores | 8.21 (4.73)a | 15.16 (3.62)b | 12.00 (5.94)a,b | <0.01 |
| TST† (h) | 5.57 (1.93)a | 2.25 (2.46)b | 4.60 (2.73)a | <0.01 |
| SOL (h) | 0.79 (0.57)a | 3.01 (1.24)b | 1.39 (1.32)a | <0.01 |
| SE | 74.78 (25.96)a | 28.88 (20.49)b | 58.28 (32.66)a | <0.01 |
| PSG findings | ||||
| TST (h) | 7.11 (0.44)a | 6.82 (0.69)a | 6.02 (1.58)b | <0.01 |
| SE | 92.79 (4.32)a | 88.04 (7.28)a | 77.25 (19.94)b | <0.01 |
| SOL (h) | 7.84 (6.60)a | 9.13 (6.58)a | 15.30 (26.40)a | 0.07 |
| Stage 1 (%) | 32.44 (16.39)a | 32.56 (16.54)a | 32.60 (13.51)a | 0.41 |
| Stage 2 (%) | 21.67 (9.19)a | 20.21 (10.27)a | 16.28 (9.33)a | 0.32 |
| Stage 3 (%) | 30.65 (18.39)a | 23.94 (15.12)a | 19.17 (16.82)a | 0.15 |
| REM (%) | 8.01 (8.30)a | 11.32 (8.86)a | 9.13 (9.79)a | 0.81 |
| REM arousality | 20.50 (11.05)a | 23.86 (12.62)a | 24.31 (18.28)a | 0.93 |
| nREM arousality | 24.76 (9.02)a | 24.74 (6.26)a | 22.99 (5.43)a | 0.69 |
| Average pulse transit time | 305.93 (10.78)a | 299.79 (17.91)a | 308.24 (14.72)a | 0.23 |
| Wake index | 2.02 (0.68)a | 3.54 (1.92)a | 8.92 (10.81)b | <0.01 |
| WASO | 14.53 (4.68)a | 23.36 (11.94)a | 40.58 (28.32)b | <0.01 |
†Mean (SD). Statistical analysis for the equality of the mean values among three groups was evaluated using ANCOVA adjusted by sex, age, and BMI (P<0.05). Means with the same superscript letters within a row were not significantly different (P>0.05). TST – Total sleep time; SE – Sleep efficiency; SOL – Sleep onset latency; REM – Rapid eye movement stage; nREM – non-rapid eye movement stage; WASO – Wake after sleep onset; SD – Standard deviation; BMI – Body mass index; PSG – Polysomnography; PSQI – Pittsburgh sleep quality index