Table 2.
Linear mixed effects models for associations between sleep–wake regularity (ISsw), heart rate variability (HF), and mood (BDI)
| Model | BDI | ΔBDI | |||||
|---|---|---|---|---|---|---|---|
| b | 95% CI | P | b | 95% CI | P | ||
| 1a | ISSW | −0.16 | (−0.24 to −0.08) | 0.0003*** | −0.11 | (−0.17 to −0.05) | 0.0009*** |
| 1b | ISSW | −0.19 | (−0.27 to −0.11) | 0.00002*** | −0.13 | (−0.19 to −0.06) | 0.0002*** |
| HF sleep | 5.87 | (1.77 to 9.98) | 0.006** | 3.03 | (0.16 to 5.91) | 0.039* | |
| 1c | ISSW | −0.21 | (−0.29 to −0.13) | 0.000002*** | −0.14 | (−0.20 to −0.08) | 0.00001*** |
| HF sleep† | 6.46 | (2.68 to 10.2) | 0.002** | 3.08 | (0.44 to 5.72) | 0.023* | |
| ISSW * HF-sleep† | −0.27 | (−0.45 to −0.09) | 0.005** | −0.21 | (−0.34 to −0.08) | 0.003** |
Linear mixed effects models showing the effects of weekly ISsw (Model 1a), with HF sleep (Model 1b), and also with ISsw *HF sleep (Model 1c) on weekly mood (BDI) and change in mood (ΔBDI). Adjusted for demographics, physical activity, mean sleep duration, and heart rate during sleep.
BDI = Beck Depression Inventory; ΔBDI = change in BDI; ISsw = interdaily stability of sleep–wake times; HF sleep = high-frequency power during sleep.
Bold values indicate statistically significant (p < 0.05).
†log-transformed. *p < 0.05; **p < 0.01; ***p < 0.001.