Table 2. Between-group comparisons for HRV values at baseline using t-test.
| Variable | MCI ( n = 22) | HC ( n = 29) | p-value | Effect size d |
|---|---|---|---|---|
| mHR (bpm) | 65.96 ± 7.82 | 63.98 ± 7.16 | 0.352 | 0.266 |
| SDNN (ms) | 21.62 ± 8.50 | 28.56 ± 14.49 | 0.051 | 0.565 |
| RMSSD (ms) | 25.05 ± 10.49 | 27.57 ± 15.13 | 0.507 | 0.189 |
| LF (ms 2 ) | 214.07 ± 312.20 | 542.91 ± 800.37 | 0.075 | 0.515 |
| HF (ms 2 ) | 162.00 ± 107.28 | 283.70 ± 295.74 | 0.048* | 0.519 |
| TP (ms 2 ) | 428.14 ± 424.21 | 906.58 ± 1033.20 | 0.030* | 0.577 |
| LF/HF | 1.51 ± 1.55 | 2.58 ± 3.32 | 0.171 | 0.395 |
| SD2 (ms) | 24.24 ± 11.14 | 35.03 ± 18.07 | 0.017* | 0.697 |
| D2 | 0.47 ± 0.92 | 1.20 ± 1.42 | 0.030* | 0.593 |
| DFA1 | 0.84 ± 0.33 | 1.05 ± 0.29 | 0.017* | 0.682 |
Abbreviations: bpm, beats per minute; D2, correlation dimension; DFA1, detrended fluctuation analysis; HC, healthy controls; HF, high frequency power; LF, low frequency power; MCI, mild cognitive impairment; mHR, mean heart rate; ms, millisecond; RMSSD, root mean square of successive NN interval differences; SDNN, standard deviation of all NN intervals; SD2, standard deviation along the line of identity in the Poincaré plot; TP, total power; VFT, verbal fluency task.
Note: variables expressed as mean ± standard deviation; * p < 0.05.