Table 2 Day–night differences in the slope (β) of fractal scaling and in various frequency-domain measures of heart rate variability
Study stage | n | 24-h MESOR | Awake | Asleep | Difference between awake and asleep | |||||
|---|---|---|---|---|---|---|---|---|---|---|
Mean | s.d. | Mean | s.d. | Mean | s.d. | Paired t | P-value | |||
Slope of 1/f | Pre | 7 | −1.156 | 0.100 | −1.243 | 0.113 | −0.811 | 0.282 | ||
F01 | 7 | −1.006 | 0.137 | −1.051 | 0.106 | −0.747 | 0.265 | |||
F02 | 7 | −0.918 | 0.159 | −0.994 | 0.124 | −0.717 | 0.316 | |||
F03 | 7 | −0.922 | 0.101 | −1.033 | 0.104 | −0.664 | 0.247 | |||
Post | 7 | −1.170 | 0.162 | −1.253 | 0.174 | −0.827 | 0.258 | |||
Earth | 7 | −1.163 | 0.125 | −1.248 | 0.140 | −0.819 | 0.255 | 5.409 | <0.010 | |
Space | 7 | −0.949 | 0.099 | −1.026 | 0.077 | −0.710 | 0.252 | 3.261 | 0.085 | |
ULF component (0.0001–0.003 Hz) | Pre | 7 | 4314.8 | 2903.5 | 5364.4 | 4808.4 | 2737.8 | 1434.0 | ||
F01 | 7 | 3364.1 | 1983.0 | 3641.4 | 1613.1 | 2334.0 | 1404.0 | |||
F02 | 7 | 2411.0 | 1750.0 | 3295.4 | 3126.0 | 1954.5 | 1480.2 | |||
F03 | 7 | 3103.6 | 1950.0 | 4620.6 | 3590.3 | 2112.9 | 1068.8 | |||
Post | 7 | 4052.1 | 1965.3 | 4415.2 | 2108.0 | 2818.3 | 1328.7 | |||
Earth | 7 | 4183.5 | 2416.9 | 4889.8 | 3410.0 | 2778.1 | 1373.7 | 2.351 | NS | |
Space | 7 | 2959.6 | 1617.3 | 3852.5 | 2517.4 | 2133.8 | 1187.9 | 1.853 | NS | |
VLF component (0.003–0.04 Hz) | Pre | 7 | 2185.2 | 1756.7 | 2184.4 | 1857.4 | 3501.6 | 3699.9 | ||
F01 | 7 | 1718.8 | 959.1 | 1847.6 | 972.6 | 2699.4 | 2027.5 | |||
F02 | 7 | 1533.1 | 815.4 | 1592.7 | 718.7 | 2167.6 | 1738.8 | |||
F03 | 7 | 1873.6 | 1148.8 | 1878.6 | 1102.5 | 3211.2 | 3326.0 | |||
Post | 7 | 2022.9 | 1091.0 | 2011.8 | 1113.9 | 3226.8 | 2977.3 | |||
Earth | 7 | 2104.1 | 1408.9 | 2098.1 | 1471.3 | 3364.2 | 3330.0 | 1.201 | NS | |
Space | 7 | 1708.5 | 932.8 | 1773.0 | 893.9 | 2692.7 | 2267.4 | 1.277 | NS | |
LF component (0.04–0.15 Hz) | Pre | 7 | 697.6 | 360.6 | 680.5 | 321.7 | 884.0 | 609.6 | ||
F01 | 7 | 653.2 | 371.9 | 638.0 | 352.9 | 832.2 | 614.0 | |||
F02 | 7 | 612.6 | 322.1 | 563.5 | 262.0 | 806.5 | 545.5 | |||
F03 | 7 | 670.2 | 345.2 | 600.7 | 288.7 | 956.3 | 638.8 | |||
Post | 7 | 668.6 | 282.7 | 632.5 | 247.8 | 985.5 | 686.6 | |||
Earth | 7 | 683.1 | 309.7 | 656.5 | 270.4 | 934.8 | 647.0 | 1.577 | NS | |
Space | 7 | 645.3 | 337.3 | 600.7 | 293.6 | 865.0 | 595.3 | 1.762 | NS | |
HF component (0.15–0.40 Hz) | Pre | 7 | 118.8 | 58.8 | 102.7 | 49.5 | 188.5 | 115.2 | ||
F01 | 7 | 113.2 | 71.2 | 100.7 | 64.8 | 150.0 | 89.2 | |||
F02 | 7 | 101.5 | 51.2 | 87.1 | 40.4 | 148.0 | 93.6 | |||
F03 | 7 | 133.1 | 67.8 | 106.9 | 48.0 | 222.7 | 162.2 | |||
Post | 7 | 116.3 | 53.4 | 104.6 | 51.0 | 181.5 | 73.8 | |||
Earth | 7 | 117.5 | 50.0 | 103.7 | 43.9 | 185.0 | 89.3 | 3.737 | 0.050 | |
Space | 7 | 115.9 | 59.8 | 98.3 | 49.2 | 173.6 | 107.4 | 2.944 | 0.130 | |
