Table 1.
Age, BMI, habitual and scheduled sleep characteristics, and DLMO of early and late sleepers.
| Early sleep (n = 11) | Late sleep (n = 17) | p* | |
|---|---|---|---|
| Age (years) | 22.23 ± 2.23 (19.29–28.53) | 22.12 ± 2.57 (18.44–26.96) | 0.92 |
| Body mass index (kg/m2) | 21.21 ± 2.30 (18.66–25.85) | 22.56 ± 2.83 (18.95–29.00) | 0.18 |
| Habitual bed time (h) | 23:41 ± 0:57 (22:23–01:47) | 00:42 ± 0:51 (22:55–01:55) | <0.01 |
| Habitual wake time (h) | 07:22 ± 0:55 (06:12–9:17) | 08:51 ± 0:43 (07:38–10:12) | <0.001 |
| Habitual time in bed (h) | 7.69 ± 0.71 (6.28–8.78) | 8.14 ± 0.82 (7.00–9.97) | 0.14 |
| Sleep onset time (h) during scheduled sleep | 22:51 ± 0:15 (22:28–23:13) | 00:41 ± 0:08 (00:28–00:58) | <0.001 |
| Wake time (h) during scheduled sleep | 06:16 ± 0:08 (06:00–06:24) | 08:12 ± 0:14 (07:38–8:27) | <0.001 |
| Time in bed (h) during scheduled sleep | 7.42 ± 0.29 (6.92–7.93) | 7.53 ± 0.28 (6.98–7.85) | 0.34 |
| MEQ score | 58.09 ± 5.61 (47–65) | 48.82 ± 5.57 (38–56) | <0.001 |
| DLMO (h) | 21:00 ± 0:41 (19:51–22:14) | 22:43 ± 01:15 (20:29–0:52) | <0.001 |
Mean ± SD (range) is shown for each parameter.
*Independent samples t-test, two-tailed.