Table 2. Effects of mixed effects regression model coefficients on heart rate and heart rate variability.

Parameter	HR	LF	HF	LF/HF
Intercept1	73.60 ± 2.73***	1.17 ± 0.21***	0.43 ± 0.28	1.11 ± 0.19***
Non-REM1	-13.02 ± 1.03***	-0.39 ± 0.10***	-0.61 ± 0.11	-0.45 ± 0.09***
Non-REM2	-15.12 ± 0.94***	-0.72 ± 0.12***	-0.59 ± 0.11	-0.67 ± 0.08***
Non-REM3	-13.42 ± 0.98***	-1.06 ± 0.13***	-0.21 ± 0.13	-0.85 ± 0.10***
REM	-12.07 ± 1.02***	-0.63 ± 0.11***	-0.55 ± 0.13***	0.08 ± 0.10
Apnea/hypopnea	-0.34 ± 0.17*	0.46 ± 0.03***	0.27 ± 0.03***	0.19 ± 0.03***
Leg movements	0.97 ± 0.14***	0.78 ± 0.02***	0.06 ± 0.02*	0.73 ± 0.02***
Arousal transitions2	2.25 ± 0.20***	0.34 ± 0.03***	0.07 ± 0.03*	0.27 ± 0.03***
Gender	-4.09 ± 2.73	-0.38 ± 0.22	-1.11 ± 0.29***	0.70 ± 0.19**
Disease	4.19 ± 2.70	-0.22 ± 0.23	-0.03 ± 0.31	-0.20 ± 0.19

Values represent the effect of model coefficients on HR, LF, HF, and LF/HF, displayed as the mean (± SEM) deviation from the intercept (i.e. wake before sleep onset). HR, heart rate in beats per minute; LF, low frequency power in ln(ms²/Hz); HF, high frequency power in ln(ms²/Hz); REM, rapid eye movement sleep.

¹Wake before sleep onset.

²Transition from deep to light sleep.

*P < 0.05;

**P < 0.01;

***P < 0.001.