Table 4. Results of a repeated measures ANOVA of the behavioral rhythm and sleep parameters between Nights 1 and 2 and high and low mood disorder questionnaire (MDQ) score groups.
| Type of sample | Variables | Nights | High MDQ score group (n = 14 or 13) | Low MDQ score group (n = 11 or 8) | Source | F | p |
|---|---|---|---|---|---|---|---|
| Mean ± SD | Mean ± SD | ||||||
| Behavioral rhythm (n = 25) | Period (hr) | Night 1 | 23.914 ± 0.728 | 24.255 ± 0.391 | Nights | 2.375 | 0.137 |
| (n = 25) | Night 2 | 24.086 ± 0.429 | 23.664 ± 0.687 | Group | 0.046 | 0.832 | |
| Night*Group | 7.844 | 0.010† | |||||
| Amplitude | Night 1 | 157.870 ± 37.402 | 181.644 ± 67.692 | Nights | 0.839 | 0.369 | |
| Night 2 | 196.098 ± 47.618 | 170.456 ± 59.610 | Group | 0.004 | 0.952 | ||
| Night*Group | 2.804 | 0.108 | |||||
| Acrophase (time) | Night 1 | 15.339 ± 1.695 | 16.045 ± 1.736 | Nights | 0.518 | 0.479 | |
| Night 2 | 15.279 ± 1.359 | 15.399 ± 1.593 | Group | 0.987 | 0.331 | ||
| Night*Group | 0.358 | 0.555 | |||||
| Mesor | Night 1 | 218.217 ± 74.838 | 274.828 ± 55.845 | Nights | 0.013 | 0.911 | |
| Night 2 | 248.568 ± 66.164 | 240.369 ± 53.528 | Group | 1.713 | 0.204 | ||
| Night*Group | 3.212 | 0.086 | |||||
| Robustness (%) | Night 1 | 24.921 ± 9.231 | 22.845 ± 5.884 | Nights | 0.047 | 0.830 | |
| Night 2 | 23.364 ± 4.939 | 23.618 ± 5.922 | Group | 0.196 | 0.662 | ||
| Night*Group | 0.417 | 0.525 | |||||
| Sleep parameters | TST (min) | Night 1 | 387.12 ± 19.777 | 379.94 ± 15.481 | Nights | 0.658 | 0.427 |
| (n = 21) | Night 2 | 387.038 ± 17.578 | 383.125 ± 15.038 | Group | 0.528 | 0.476 | |
| Night*Group | 0.725 | 0.405 | |||||
| SE (%) | Night 1 | 97.246 ± 1.624 | 97.738 ± 1.561 | Nights | 0.006 | 0.940 | |
| Night 2 | 97.200 ± 2.010 | 97.738 ± 1.369 | Group | 0.536 | 0.473 | ||
| Night*Group | 0.006 | 0.940 | |||||
| WASO (min) | Night 1 | 6.462 ± 4.850 | 5.313 ± 6.193 | Nights | 0.255 | 0.619 | |
| Night 2 | 6.500 ± 5.583 | 4.500 ± 5.345 | Group | 0.460 | 0.506 | ||
| Night*Group | 0.309 | 0.585 | |||||
| SL (min) | Night 1 | 4.308 ± 2.905 | 3.500 ± 2.155 | Nights | 0.643 | 0.432 | |
| Night 2 | 4.58 ± 2.907 | 4.44 ± 3.649 | Group | 0.190 | 0.668 | ||
| Night*Group | 0.197 | 0.662 | |||||
| Stage N1 (%) | Night 1 | 13.046 ± 5.067 | 10.988 ± 4.716 | Nights | 0.729 | 0.404 | |
| Night 2 | 15.262 ± 7.280 | 10.363 ± 4.469 | Group | 2.116 | 0.162 | ||
| Night*Group | 2.325 | 0.144 | |||||
| Stage N2 (%) | Night 1 | 45.708 ± 6.552 | 44.550 ± 4.612 | Nights | 0.579 | 0.456 | |
| Night 2 | 46.092 ± 6.024 | 41.825 ± 4.815 | Group | 1.696 | 0.208 | ||
| Night*Group | 1.022 | 0.325 | |||||
| Stage N3 (%) | Night 1 | 17.738 ± 8.495 | 20.100 ± 5.310 | Nights | 0.283 | 0.601 | |
| Night 2 | 14.946 ± 9.784 | 21.800 ± 4.009 | Group | 1.879 | 0.186 | ||
| Night*Group | 4.785 | 0.041† | |||||
| Stage R (%) | Night 1 | 23.508 ± 5.740 | 24.400 ± 2.852 | Nights | 0.946 | 0.343 | |
| Night 2 | 23.685 ± 3.926 | 26.013 ± 3.186 | Group | 0.888 | 0.358 | ||
| Night*Group | 0.609 | 0.445 | |||||
| Stage R latency (min) | Night 1 | 77.88 ± 45.513 | 60.94 ± 37.282 | Nights | 0.017 | 0.897 | |
| Night 2 | 76.346 ± 46.806 | 64.313 ± 30.495 | Group | 0.679 | 0.420 | ||
| Night*Group | 0.124 | 0.729 | |||||
| RDI | Night 1 | 4.646 ± 3.096 | 3.125 ± 2.518 | Nights | 0.011 | 0.918 | |
| Night 2 | 4.62 ± 3.655 | 3.23 ± 3.179 | Group | 1.099 | 0.308 | ||
| Night*Group | 0.028 | 0.869 | |||||
| AHI | Night 1 | 2.823 ± 1.836 | 1.800 ± 1.489 | Nights | 0.001 | 0.971 | |
| Night 2 | 2.62 ± 2.690 | 2.03 ± 1.946 | Group | 0.838 | 0.371 | ||
| Night*Group | 0.391 | 0.539 | |||||
| RERAI | Night 1 | 2.07 ± 2.53 | 1.51 ± 1.34 | Nights | 2.246 | 0.149 | |
| Night 2 | 1.63 ± 1.96 | 1.28 ± 1.17 | Group | 1.027 | 0.324 | ||
| Night*Group | 0.198 | 0.661 | |||||
| PLMI | Night 1 | 3.28 ± 7.356 | 0.33 ± 0.709 | Nights | 0.662 | 0.426 | |
| Night 2 | 4.223 ± 10.2807 | 0.825 ± 1.086 | Group | 1.065 | 0.315 | ||
| Night*Group | 0.063 | 0.805 | |||||
| LMI | Night 1 | 6.892 ± 7.894 | 3.700 ± 1.922 | Nights | 1.505 | 0.235 | |
| Night 2 | 8.169 ± 11.440 | 4.925 ± 2.895 | Group | 0.883 | 0.359 | ||
| Night*Group | 0.001 | 0.980 | |||||
| TA (min) | Night 1 | 13.638 ± 4.409 | 11.838 ± 3.996 | Nights | 0.054 | 0.820 | |
| Night 2 | 15.115 ± 5.842 | 10.638 ± 2.811 | Group | 2.498 | 0.130 | ||
| Night*Group | 5.000 | 0.038† | |||||
| SA (min) | Night 1 | 8.046 ± 3.649 | 8.063 ± 4.294 | Nights | 0.036 | 0.852 | |
| Night 2 | 9.300 ± 5.302 | 7.000 ± 2.622 | Group | 0.392 | 0.539 | ||
| Night*Group | 5.266 | 0.033 | |||||
| Supine position (%) | Night 1 | 76.823 ± 21.330 | 79.363 ± 13.726 | Nights | 0.882 | 0.359 | |
| Night 2 | 78.177 ± 21.308 | 83.625 ± 20.624 | Group | 0.222 | 0.643 | ||
| Night*Group | 0.237 | 0.632 |
†p-value < 0.05.
Night 1, exposure to artificial light of 150-lux intensity at night.
Night 2, exposure to artificial light of 1000-lux intensity at night.
The numbers of subjects in the high MDQ score group (n = 14) and the low MDQ score group (n = 11) are for the variables of behavioral rhythm. However, sleep parameters have different numbers of subjects in each group: high MDQ score group (n = 13) and low MDQ score group (n = 8).
hr, hour; time, time of the day; TST, total sleep time; SE, sleep efficiency; WASO, wake time after sleep onset; SL, sleep latency; AHI, apnea + hypopnea index; RDI, respiratory disturbance index; RERAI, respiratory effort-related arousal index; PLMI, periodic limb movement during sleep index; LMI, limb movement index; TA, total arousal; SA, spontaneous arousal; min, minutes; n, number of subjects; and SD, standard deviation.