Table 1.
Demographics and Sleep Data for the Entire Group and by Subgroups
Parameter | Subjects |
p Valuea | ||
---|---|---|---|---|
All | MSL ≥ 8 | MSL < 8 | ||
No. | 54 | 35 | 19 | |
Age, y | 30.74 ± 10.39 | 30.09 ± 10.78 | 31.95 ± 9.79 | 0.3454 |
Men, % | 87.04 | 82.86 | 94.73 | 0.4001 |
BMI, kg/m2 | 27.95 ± 4.45 | 27.30 ± 4.87 | 29.14 ± 3.32 | 0.1477 |
ESS score | 16.15 ± 4.70 | 15.37 ± 4.47 | 17.58 ± 4.89 | 0.0997 |
Caffeineb | 2.45 ± 2.41 | 2.71 ± 2.67 | 1.97 ± 1.8 | 0.4303 |
Self-reported naps, no./wk | 4.40 ± 3.26 | 3.99 ± 2.54 | 5.13 ± 4.25 | 0.5200 |
AHI, no./h | 2.22 ± 3.44 | 2.18 ± 3.45 | 2.31 ± 3.53 | 0.5622 |
MSL, min | 9.75 ± 4.49 | 12.30 ± 3.53 | 5.05 ± 1.51 | <0.0001* |
Sleep-onset REM periods, no. | 0.65 ± 1.07 | 0.49 ± 1.07 | 0.95 ± 1.13 | 0.1012 |
Average nightly sleep duration, h | ||||
Self-reported | 6.13 ± 1.23 | 6.11 ± 1.36 | 6.18 ± 0.97 | 0.9413 |
Sleep log-recorded | 6.99 ± 0.85 | 6.94 ± 0.93 | 7.08 ± 0.70 | 0.5914 |
Actigraphy-measured | 5.56 ± 1.50 | 6.10 ±1.37 | 4.53 ± 1.37 | 0.0001* |
Differencec | 1.43 ± 1.31 | 0.84 ± 0.83 | 2.55 ± 1.41 | 0.0004* |
Sleep duration on PSG lab night, h | ||||
By actigraphy | 7.09 ± 1.40 | 7.17 ± 1.65 | 6.93 ± 1.83 | 0.8779 |
By PSG | 7.35 ± 0.65 | 7.29 ± 1.36 | 7.47 ± 0.62 | 0.1920 |
Sleep efficiency, % | ||||
Measured by actigraphy | ||||
At home | 83.19 ± 14.13 | 87.36 ± 11.11 | 75.31 ± 16.08 | 0.0071* |
In lab | 89.62 ± 13.96 | 91.74 ± 9.66 | 85.49 ± 19.56 | 0.5873 |
Measured by PSG | 91.48 ± 6.29 | 91.69 ± 6.26 | 91.10 ± 6.48 | 0.6969 |
p Value is based on comparison of subgroups with mean sleep latency (MSL) ≥ 8 vs MSL < 8 minutes. Data are presented as mean ± SD unless otherwise indicated. BMI refers to body mass index; AHI, apnea-hypopnea index; REM, rapid eye movement.
Cups of coffee or tea or cans of soft drink per day.
Difference between sleep log and actigraphy-measured average nightly sleep duration.
Statistically significant