Table 2.
The Effect of Short Sleep Duration (Less than 9 Hours) on Outcomes
| Variable | Univariate analysis | Multivariable model 1* | Multivariable model 2† | |||
|---|---|---|---|---|---|---|
| Overweight/ Obese (OR)# | 3.92 (1.91, 8.06) | P = 0.0002 | 3.86 (1.83, 8.13) | P = 0.0004 | 3.32 (1.40, 7.87) | P = 0.0064 |
| Percentage body fat (%) | 4.53 (1.51, 7.55) | P = 0.0034 | 4.58 (1.50, 7.65) | P = 0.0036 | 3.34 (0.31, 6.38) | P = 0.03 |
| Weight (kg) | 3.61 (1.34, 5.89) | P = 0.0019 | 3.78 (1.43, 6.12) | P = 0.0017 | ||
| Height (cm) | 1.82 (−0.50, 4.14) | P = 0.12 | 2.08 (-0.24, 4.41) | P = 0.08 | ||
| IQ points | 0.41 (−4.00, 4.82) | P = 0.86 | ||||
| Total counts (x104) | 5.13 (−3.04, 13.30) | P = 0.22 | ||||
| Mean counts | −21 (−125, 83) | P = 0.69 | ||||
| Sedentary activity (min) | 69 (35, 103) | P <0.0001 | 64 (30, 97) | P = 0.0002 | ||
| Moderate activity (min) | 14 (−7, 35) | P = 0.18 | ||||
| Vigorous activity (min) | 2 (−8, 12) | P = 0.38 | ||||
| SDQ (OR for abnormal)# | 1.39 (0.52, 3.72) | P = 0.45 | ||||
| Emotional lability‡ | 0.17 (0.01, 0.33) | P = 0.03 | 0.18 (0.02, 0.34) | P = 0.03 | ||
| Systolic blood pressure (mmHg) | 3.43 (0.55, 6.31) | P = 0.02 | 3.62 (0.64, 6.61) | P = 0.02 | ||
| (not significant when adjusted for body weight or BMI) | ||||||
*
Multivariable model 1 adjusting for season, weekday and younger siblings.
†
Multivariable model 2 adjusting for maternal age, BMI and marital status, gender, TV watching and time spent in sedentary activity.
‡
Parent Conners Rating Scale for emotional lability.
#
As this is a dichotomous variable the estimate is an odds ratio.