Table 1.
Baseline characteristics of the sample according to sleep duration categories
| Sleep duration categories | |||||
|---|---|---|---|---|---|
| ≤9 h | >9 h to ≤10 h | >10 h to ≤11 h | >11 h | P | |
| Boys/Girls (N) | 493/478 | 1410/1389 | 1509/1398 | 637/660 | |
| Age (years) | 6.3 (6.2;6.4) | 6.4 (6.3;6.5) | 6.1 (6.1;6.2) | 5.4 (5.3;5.5) | <0.001* |
| SBP (mm Hg)a | 101.2 (100.7;101.8) | 101.0 (100.7;101.3) | 100.4 (100.1;100.7) | 99.7 (99.2;100.2) | <0.001* |
| DBP (mm Hg)a | 63.9 (63.5;64.3) | 63.5 (63.2;63.7) | 62.9 (62.7;63.2) | 62.5 (62.1;62.8) | <0.001* |
| Prevalence of elevated BP/hypertension % (N) | 18.5 (180) | 17.5 (491) | 15.9 (463) | 11.6 (151) | χ2 ≤ 0.001 # |
| BMI z‐scoreb | 0.5 (0.5;0.6) | 0.4 (0.4;0.5) | 0.3 (0.3;0.4) | 0.2 (0.2;0.3) | <0.001* |
| Screen time (hours per week)a | 13.1 (12.6;13.5) | 12.3 (12.0;12.6) | 11.5 (11.3;11.8) | 11.1 (10.7;11.5) | <0.001* |
| Physical activity (%) Yes | 46.2 | 46.4 | 47.7 | 47.9 | χ2 = 0.684 # |
| Parental education (%) High | 16.3 | 29.0 | 35.9 | 33.4 | χ2 ≤ 0.001 # |
Data are expressed as mean (95% confidence interval) or as frequency (%).
DBP, diastolic blood pressure; SBP, systolic blood pressure.
a
Analysis adjusted by age, sex, BMI z‐score, and country of origin.
b
Analysis adjusted by age, sex, and country of origin.
*
P value for trend.
#
P by Linear‐by‐linear association.