Table 3. Results of the longitudinal relationship between sleep duration and BMI using panel data analysis (n = 1687, 5061 records).
| Variables on models | 1-year changes in BMI (kg/m2) | |||
| Population-averaged model | Fixed-effects model | |||
| B | 95% CI | B | 95% CI | |
| Sleep duration | ||||
| ≤4 hours | 0.05 | (−0.07, 0.17) | 0.08 | (−0.08, 0.25) |
| 5 hours | 0.11 | (0.05, 0.18) | 0.07 | (−0.03, 0.18) |
| 6 hours | 0.07 | (0.00, 0.13) | 0.02 | (−0.06, 0.11) |
| 7 hours | 0.00 | (Reference) | 0.00 | (Reference) |
| ≥8 hours | 0.19 | (0.05, 0.33) | 0.06 | (−0.11, 0.24) |
| Exercise (reference, none) | ||||
| Regular exerciser | −0.01 | (−0.06, 0.03) | −0.13 | (−0.20, −0.06) |
| Smoking (reference, non-smoker) | ||||
| Smoker | 0.07 | (0.03, 0.11) | 0.05 | (−0.08, 0.19) |
| Alcohol consumption (reference, 0 g/week) | ||||
| 1–139 g/week | 0.00 | (−0.06, 0.06) | −0.01 | (−0.14, 0.12) |
| ≥140 g/week | 0.00 | (−0.07, 0.06) | −0.03 | (−0.18, 0.12) |
| Psychiatric medications (reference, none) | 0.22 | (−0.24, 0.67) | −0.02 | (−0.55, 0.51) |
| Symptoms (reference, none) | ||||
| Depression | 0.13 | (0.02, 0.24) | 0.12 | (0.00, 0.25) |
| Ill health | −0.01 | (−0.17, 0.16) | 0.06 | (−0.13, 0.24) |
| Sleep disturbance | 0.03 | (−0.11, 0.16) | 0.00 | (−0.16, 0.17) |
| Midmorning sleepiness | 0.00 | (−0.12, 0.13) | 0.10 | (−0.05, 0.25) |
| Midmorning fatigue | −0.01 | (−0.13, 0.10) | −0.12 | (−0.26, 0.02) |
| Age (years) | 0.00 | (−0.01, 0.00) | 0.12 | (0.10, 0.14) |
| BMI (kg/m2) | −0.01 | (−0.02, −0.01) | −1.01 | (−1.04, −0.98) |
B, beta coefficient; BMI, body mass index; CI, confidence interval.