Table 1.
Summary of demographic, actigraphic and physiological variables for ECPs and LCPs
| Variable measured (mean ± SEM) | ECPs | LCPs | Significance |
|---|---|---|---|
| Demographic variables | |||
| Sample size | N = 16 | N = 22 | n/a |
| Number of scans/testing sessions | N = 48 | N = 66 | n/a |
| Percentage of males/females (%) | M = 43.8 | M = 31.8 | nsc |
| F = 56.3 | F = 68.2 | nsc | |
| Age (years) (mean ± SD) | 24.7 ± 4.0 | 21.2 ± 3.3 | p = 0.028a |
| Height (cm) | 171.3 ± 2.0 | 171.1 ± 2.4 | nsa |
| Weight (kg) | 66.4 ± 2.8 | 67.1 ± 2.1 | nsa |
| MCTQ score (hours:minutes) | 02:24 ± 00:10 | 06:52 ± 00:17 | p < 0.0001a |
| Actigraphic variables | |||
| Sleep onset (hours:minutes) | 22:57 ± 00:10 | 02:27 ± 00:19 | p < 0.0001a |
| Wake-up time (hours:minutes) | 06:33 ± 0.10 | 10:13 ± 00:18 | p < 0.0001a |
| Sleep duration (hours) | 7.59 ± 0.18 | 7.70 ± 0.14 | nsa |
| Sleep efficiency (%) | 79.29 ± 1.96 | 77.23 ± 1.14 | nsa |
| Sleep onset latency (hours:minutes) | 00:25 ± 00:06 | 00:25 ± 00:03 | nsb |
| Physiological variables | |||
| Phase angle (hours:minutes) | 02:28 ± 00:16 | 02:34 ± 00:18 | nsa |
| Dim light melatonin onset (hours:minutes) | 20:27 ± 00:16 | 23:55 ± 00:26 | p < 0.0001a |
| Cortisol peak time (hours:minutes) | 07:04 ± 00:16 | 11:13 ± 00:23 | p < 0.0001a |
| External variables (between sessions) | |||
| Hours since last meal (hours) | 3.58 ± 0.55 | 5.07 ± 0.58 | nsb |
| Hours since caffeine (hours) | 8.47 ± 0.67 | 7.85 ± 0.82 | nsb |
| Hours since exercise (hours) | 6.78 ± 0.74 | 7.44 ± 0.74 | nsb |
| Hours since natural light exposure (hours) | 5.87 ± 0.80 | 3.51 ± 0.58 | nsb |
| Hours since indoor light exposure (hours) | 1.88 ± 0.38 | 3.32 ± 0.51 | nsb |
Values are shown as mean ± SEM unless specified. Significance is shown with aparametric tests, bnonparametric tests or cFisher’s exact test. Phase angle is calculated by the interval time between dim light melatonin onset and sleep onset.