Table 2.
Comparison of heart rate and 24-hr HRV between long-term CR and WD
| CR μ±SD |
WD μ±SD |
p-value | |
|---|---|---|---|
| Average HR for 24 hr (bpm) | 57±6 | 76±9 | < 0.001 |
| Average daytime HR (bpm) | 61±7 | 81±10 | < 0.001 |
| Average nighttime HR (bpm) | 50±5 | 67±10 | < 0.001 |
| Maximum instantaneous HR (bpm) | 110±22 | 129±14 | 0.001 |
| Minimum instantaneous HR (bpm) | 37±4 | 45±10 | 0.002 |
| SDNN (ms) | 168±26 | 128±46 | 0.001 |
| SDANN (ms) | 149±20 | 119±38 | 0.005 |
| SDNNIDX (ms) | 67±15 | 49±15 | <0.001 |
| rMSSD (ms) | 36±12 | 23±11 | 0.001 |
| pNN50 (%) | 12±8 | 5±5 | 0.001 |
| Total power (ms2, Median[IQR]) | 26764[9456] | 14578[16665] | |
| Ln total power | 10.2±0.3 | 9.6±0.6 | 0.002 |
| Very-low-frequency power (ms2, Median[IQR]) | 2971[1709] | 1138[1111] | |
| Ln very-low-frequency power | 7.8±0.4 | 7.1±0.6 | <0.001 |
| Low-frequency power (ms2, Median[IQR]) | 986[1026] | 508[652] | |
| Ln low-frequency power | 6.8±0.7 | 6.3±0.8 | 0.06 |
| High-frequency power (ms2, Median[IQR]) | 284 [232] | 110 [165] | |
| Ln high-frequency power | 5.7±0.7 | 4.9±1.0 | 0.004 |
| Normalized low-frequency power (%) | 64±9 | 71±9 | 0.020 |
| Normalized high-frequency power (%) | 26±7 | 20±9 | 0.017 |
Ln= natural logarithm; N-N= normal-to-normal RR intervals; 24-hr HR= 60,000/average N-N for 24-hrs in bpm; daytime HR= average HR between 08:00 and 20:00; nighttime HR= average HR between 00:00 and 06:00; min HR= 60,000/minimum instantaneous N-N; max HR= 60,000/maximum instantaneous N-N; SDNN= 24-hr standard deviation of N-N intervals in ms; SDANN=24-hr SD of 5-min-averaged N-N intervals; SDNNIDX= 24-hr average of SD of 5-min N-N intervals; rMSSD= root mean square successive difference of N-N intervals in ms; pNN50= percent of successive N-N intervals differences > 50 ms in %; total power= total spectral power of HRV; very-low-frequency power = 24-hr average of power between 0.003-0.04 Hz; low-frequency power (24-hr average of 5-min power between 0.04-0.15 Hz); high-frequency power (24-hr average of 5-min power between 0.15-0.4 Hz); normalized low-frequency power (24-hr average of the proportion of total power in each 5-min interval accounted for by the low-frequency component); normalized high-frequency power (24-hr average of the proportion of total power in each 5-min interval accounted for by the high-frequency component). Values are expressed as mean ± SD or median [IRQ].