Table 4.

Descriptive statistics and correlation analysis for PSQI global score, BDI-II score, and 24-h HRV.

Variable	M ±SD	1	2	3	4	5	6	7	8
1. PSQI global scores	5.29 ± 2.84	1
2. BDI-II socres	8.26 ± 8.61	0.617**	1
3. SDNN	170.09 ± 34.74	−0.122	−0.092	1
4. RMSSD	45.02 ± 14.93	0.002	0.014	0.591**	1
5. pNN50	20.20 ± 10.33	0.003	0.039	0.523**	0.970**	1
6. LF	1105.63 ± 563.60	−0.090	0.010	0.606**	0.665**	0.576**	1
7. HF	849.81 ± 581.01	0.068	0.036	0.582**	0.952**	0.920**	0.601**	1
8. LF/HF	1.60 ± 0.89	−0.115	−0.021	−0.255*	−0.635**	−0.655**	0.034	−0.725**	1

^*p < 0.05,

^**p < 0.01.