Table 4.
Mean (Standard Error) differences between heart rate variability values according to sleep stage and sleep cycle.
| Sleep stage and sleep cycle | Heart rate variability | |||||
|---|---|---|---|---|---|---|
| Time domain variables | Power domain variables | |||||
| Mean NN | SDNN | rMSSD | LF | HF | LF:HF | |
| Pre-sleep SWS1 |
−73.0***
(6.7) |
–0.3 (4.0) |
−20.7* (5.5) |
515.1** (169.0) |
−823.9* (269.9) |
1.14*** (0.25) |
| Pre-sleep SWS2 |
−106.6*** (8.8) |
–2.0 (4.0) |
−22.7* (5.5) |
429.2* (178.2) |
−1030.2*
(312.3) |
1.14*** (0.25) |
| Pre-sleep REM3 |
−50.9*** (9.9) |
–6.7 (4.5) |
−13.7* (5.2) |
–217.2 (234.4) |
−538.5* (212.5) |
0.67* (0.24) |
| Pre-sleep SWS3 |
−125.0*** (10.6) |
–3.8 (4.6) |
−23.4* (6.3) |
232.2 (235.4) |
−1115.3* (328.6) |
0.77** (0.28) |
| Pre-sleep REM2 |
−69.3*** (9.7) |
−15.7 (4.5)* |
−25.0** (6.1) |
–346.7 (280.8) |
−1354.8* (417.5) |
0.004 (0.34) |
| Pre-sleep REM1 |
−60.1*** (10.0) |
–12.3 (4.3) |
−19.0* (5.6) |
–217.2 (2345) |
−1254.5* (355.9) |
0.08 (0.34) |
|
SWS1 vs. SWS2 |
−33.8 (5.4)*** |
–1.48 (2.7) |
–2.0 (3.8) |
–85.9 (110.4) |
–206.4 (210.4) |
0.02 (0.7) |
| SWS1 vs. SWS3 |
−49.0 (7.4)*** |
–4.0 (3.7) |
–2.7 (5.1) |
–282.9 (164.1) |
–291.3 (269.1) |
−038* (0.17) |
| SWS2 vs. SWS3 |
−15.2* (7.4) |
–2.6 (2.3) |
–0.7 (3.4) |
–196.9 (139.3) |
–84.9 (144.1) |
−0.37* (0.17) |
| SWS1 vs. REM3 |
20.9* (8.0) |
−6.4* (3.1) |
7.0 (4.3) |
−297.9* (139.1) |
285.3 (234.5) |
−0.48*** (0.10) |
| SWS1 vs. REM2 |
2.7 (8.9) |
−15.5** (3.9) |
–5.1 (56) |
−847.4*** (228.6) |
–530.9 (415.5) |
−1.14*** (0.27) |
| SWS1 v REM1 |
11.9 (9.3) |
−12.1* (3.5) |
1.7 (5.2) |
−677.3* (229.7) |
–252.1 (301.4) |
−1.22*** (0.25) |
|
SWS2 v REM3 |
54.8*** (5.9) |
–4.6 (3.3) |
9.0 (4.1)* |
–211.9 (174.5) |
–85.0 (144.2) |
−0.48*** (0.11) |
| SWS2 v REM2 |
36.5*** (7.5) |
−13.7*** (3.7) |
–3.1 (4.8) |
−775.9* (221.3) |
–324.5 (379.9) |
−1.14*** (0.26) |
| SWS2 v REM1 |
45.7*** (9.1) |
−10.3** (3.2) |
3.7 (4.4) |
−591.4* (234.5) |
–45.7 (318.8) |
−1.22*** (0.23) |
|
SWS3 v REM3 |
69.9*** (8.6) |
–2.9 (3.9) |
9.7* (4.6) |
15.0 (205.2) |
576.7 (289.6) |
–0.10 (0.19) |
| SWS3 v REM2 |
51.7*** (8.3) |
−11.9** (3.9) |
–2.4 (4.9) |
−578.9* (245.4) |
–239.6 (321.7) |
−0.76* (0.26) |
| SWS3 v REM1 |
60.9*** (10.8) |
−8.5* (3.5) |
4.3 (4.5) |
–394.5 (256.7) |
–39.2 (304.8) |
−0.84** (0.24) |
|
REM3 vs. REM2 |
−198.2* (7.7) |
−9.1* (4.0) |
−12.2* (5.1) |
–563.9 (294.6) |
−816.3* (356.5) |
−0.66** (0.25) |
| REM3 vs. REM1 |
–9.0 (8.5) |
–5.6 (2.8) |
–5.3 (3.4) |
–379.4 (284.9) |
−537.4* (259.9) |
−0.75** (0.22) |
|
REM2 vs. REM1 |
–9.2 (7.5) |
–3.4 (3.1) |
–6.8 (4.2) |
184.5 (141.9) |
278.9 (379.2) |
0.09 (0.18) |
*
Denotes p < 0.05,
**
p < 0.01,
and
***
p < 0.001 (significant differences are bolded).
SWS, slow wave sleep. SWS cycles are labeled relative to initial sleep onset: SWS cycle after sleep onset = 1st SWS, SWS cycle after sleep onset but one = 2nd SWS and SWS cycle after sleep onset but two = 3rd SWS cycle. REM = rapid eye movement sleep. REM cycles are labeled relative to sleep offset: REM cycle prior to sleep offset = REM1, REM cycle preceding sleep offset but one = REM2 and REM cycle preceding sleep offset but two = REM3 (see Figure 1).