Table 2.
Polysomnographic parameters across the study subgroups
| 1. None (n = 255) | 2. PLMS (n = 68) | 3. ADHD (n = 63) | 4. ADHD + PLMS (n = 35) | 1 vs. 2 | 1 vs. 3 | 1 vs. 4 | 2 vs. 4 | 3 vs.4 | |
|---|---|---|---|---|---|---|---|---|---|
| Sleep continuity | |||||||||
| Sleep onset latency (minutes) | 24.8 ± 1.5 | 26.1 ± 2.9 | 24.8 ± 3.1 | 38.9 ± 4.1 | 0.681 | 0.997 | 0.001 | 0.012 | 0.006 |
| Awakenings (#) | 35.8 ± 0.7 | 39.3 ± 1.4 | 37.1 ± 1.5 | 34.0 ± 2.0 | 0.031 | 0.425 | 0.403 | 0.032 | 0.209 |
| Wake after sleep onset (minutes) | 66.0 ± 2.7 | 79.5 ± 5.2 | 71.9 ± 5.4 | 70.1 ± 7.3 | 0.022 | 0.336 | 0.608 | 0.289 | 0.839 |
| Total sleep time (minutes) | 451.6 ± 3.5 | 436.3 ± 6.7 | 444.6 ± 6.9 | 435.8 ± 9.4 | 0.043 | 0.370 | 0.117 | 0.968 | 0.451 |
| Sleep efficiency (%) | 83.5 ± 0.6 | 80.8 ± 1.2 | 82.3 ± 1.3 | 80.5 ± 1.7 | 0.048 | 0.406 | 0.101 | 0.893 | 0.389 |
| Sleep architecture | |||||||||
| Stage 1 (%) | 0.8 ± 0.1 | 1.3 ± 0.2 | 1.0 ± 0.2 | 1.8 ± 0.2 | 0.010 | 0.401 | <0.001 | 0.090 | 0.006 |
| Stage 2 (%) | 53.4 ± 0.6 | 55.2 ± 1.1 | 53.1 ± 1.1 | 51.1 ± 1.5 | 0.145 | 0.776 | 0.157 | 0.028 | 0.302 |
| Stage 3 (%) | 27.2 ± 0.5 | 25.1 ± 1.0 | 27.6 ± 1.0 | 28.2 ± 1.4 | 0.076 | 0.700 | 0.485 | 0.076 | 0.731 |
| Stage R (%) | 18.6 ± 0.3 | 18.3 ± 0.6 | 18.3 ± 0.6 | 18.8 ± 0.9 | 0.712 | 0.696 | 0.822 | 0.661 | 0.648 |
| Sleep-disordered breathing | |||||||||
| AHI (events per hour) | 2.5 ± 0.3 | 2.7 ± 0.7 | 3.0 ± 0.7 | 3.0 ± 0.9 | 0.808 | 0.530 | 0.663 | 0.825 | 0.964 |
| AHI < 2 (%) | 64.7 | 63.2 | 49.2 | 65.7 | — | — | — | — | — |
| 2 ≤ AHI < 5 (%) | 26.3 | 23.5 | 34.9 | 28.6 | 0.832 | 0.195 | 0.967 | 0.857 | 0.404 |
| AHI ≥ 5 (%) | 9.0 | 13.2 | 15.9 | 5.7 | 0.254 | 0.117 | 0.608 | 0.274 | 0.185 |
| SpO2 | 91.5 ± 0.3 | 91.6 ± 0.6 | 91.7 ± 0.7 | 90.8 ± 0.9 | 0.813 | 0.808 | 0.451 | 0.415 | 0.416 |
| Periodic limb movements | |||||||||
| PLM (#) | 9.7 ± 1.9 | 84.4 ± 3.6 | 9.6 ± 3.8 | 92.4 ± 5.0 | <0.001 | 0.983 | <0.001 | 0.193 | <0.001 |
| PLMa (#) | 2.0 ± 0.3 | 8.9 ± 0.6 | 2.1 ± 0.6 | 7.6 ± 0.9 | <0.001 | 0.840 | <0.001 | 0.248 | <0.001 |
| PLMI (events per hour) | 1.3 ± 0.2 | 11.6 ± 0.5 | 1.3 ± 0.5 | 12.5 ± 0.7 | <0.001 | 0.995 | <0.001 | 0.371 | <0.001 |
Data are means ± standard error of the mean (SEM), adjusted for sex, race, age, and BMI percentile. p-Values are post hoc comparisons from multivariable-adjusted linear models. Bold values are statistically significant at P ≤ 0.05.
PLMA = periodic limb movement arousal index; PLMS = abnormal periodic limb movements; PLMI = periodic limb movement index.