Table 4.
Comparison of the HRV parameters among subgroups categorized by serum transferrin level.
| Transferrin-Deficient Group (n = 161) |
Normal Group (n = 265) |
p-Value | |
|---|---|---|---|
| Frequency domain | |||
| VLF (ms2) | 583.48 ± 244.77 | 706.20 ± 263.56 | 0.002 * |
| LF (ms2) | 405.84 ± 173.17 | 448.89 ± 171.33 | 0.013 * |
| HF (ms2) | 167.63 ± 77.57 | 185.69 ± 72.03 | 0.017 * |
| LF/HF ratio | 5.18 ± 2.83 | 5.85 ± 2.79 | 0.018 * |
| Time domain | |||
| SDNN (ms) | 96.26 ± 30.66 | 98.25 ± 28.31 | 0.504 |
| SDANN (ms) | 96.79 ± 31.62 | 99.79 ± 31.17 | 0.278 |
| ASDNN (ms) | 49.18 ± 12.48 | 50.26 ± 11.16 | 0.366 |
| rMSSD (ms) | 25.89 ± 6.95 | 26.85 ± 6.83 | 0.164 |
| pNN50 (%) | 48.51 ± 24.97 | 49.38 ± 22.96 | 0.719 |
Values are presented as the mean ± standard deviation. * p < 0.05. HRV, heart rate variability; VLF, very low frequency; LF, low frequency; HF, high frequency; SDNN, standard deviation of intervals of all normal beats; SDANN, standard deviation of five-minute mean R-R interval; ASDNN, mean of five-minute standard deviations of intervals; rMSSD, root mean square of the difference of successive R-R intervals; pNN50, percentage of intervals that were more than 50 ms different from the previous interval.