Table 6.
Coefficients for Moderated Mediation Models with Body Mass Index and Waist Circumference as Outcomes
| Predictor variables | Outcome variables | |||||
|---|---|---|---|---|---|---|
| M (sleep duration) | Coefficient | Y (BMI) | p | |||
| Coefficient | SE | p | SE | |||
| Mean sleep time–BMI model | ||||||
| Constant | 0.30 | 250.12 | 0.999 | 49.656 | ||
| X (mean sleep time) | 0.27 | 0.18 | 0.131 | — | — | — |
| M (sleep duration) | — | — | — | −0.023 | ||
| W (age) | 366.50 | 148.26 | 0.015 | — | — | — |
| Sleep time × status | −0.26 | 0.10 | 0.013 | — | — | — |
| C1 education | −0.35 | 2.28 | 0.878 | −0.724 | 0.242 | 0.003 |
| R2 = 0.116 | R2 = 0.15 | |||||
| F(4, 127) = 4.15, p < 0.05 | F(3, 128) = 5.00, p < 0.05 | |||||
| M (sleep duration) | Y (WC) | |||||
|---|---|---|---|---|---|---|
| Mean sleep time–WC model | ||||||
| Constant | 1.09 | 249.11 | 0.997 | 140.02 | 24.68 | 0.000 |
| X (mean sleep time) | 0.27 | 0.18 | 0.132 | — | — | — |
| M (sleep duration) | — | — | — | −0.082 | 0.02 | 0.001 |
| W (age) | 364.38 | 147.06 | 0.015 | −0.007 | 0.02 | 0.635 |
| Sleep time × status | −0.26 | 0.10 | 0.013 | — | — | — |
| R2 = 0.115 | R2 = 0.08 | |||||
| F(3, 128) = 5.56, p < 0.05 | F(2, 129) = 5.74, p < 0.05 | |||||
| M (sleep duration) | Y (WC) | |||||
|---|---|---|---|---|---|---|
| Sleep time variability–WC model | ||||||
| Constant | 426.43 | 21.63 | 0.000 | 125.21 | 11.14 | 0.000 |
| X (sleep time variability) | −1.02 | 0.34 | 0.003 | 0.02 | 0.04 | 0.012 |
| M (sleep duration) | — | — | — | −0.07 | 0.03 | 0.586 |
| W (age) | −16.05 | 13.13 | 0.223 | — | — | — |
| Sleep time × status | 0.19 | 0.20 | 0.352 | — | — | — |
| R2 = 0.288 | R2 = 0.08 | |||||
| F(3, 128) = 17.24, p < 0.001 | F(2, 129) = 5.78, p < 0.05 | |||||
Labels within the table reflect the following: X refers to the independent variable (mean sleep time, sleep time variability), Y refers to the dependent variable (BMI, waist circumference), M refers to the mediator (sleep duration), W refers to the moderator (age), and Cx refer to covariates. p-Values in bold indicate a statistically significant effect (p < .05).
BMI, body mass index.