TABLE 3.
Heart rate variability parameters in resting state and during task execution.
| Young adults (n = 31) |
Older adults (n = 44) |
Older adults–MCI (n = 28) |
P-value for ANOVA | |
| RRI (ms) | ||||
| Resting | 802.1 ± 129.4 | 830.2 ± 133.2 | 823.9 ± 90.6 | 0.659 |
| SCWT-c | 742.1 ± 127.4 | 795.2 ± 138.0 | 790.4 ± 87.3 | 0.223 |
| SCWT-ic | 745.0 ± 132.9 | 793.4 ± 136.4 | 796.0 ± 87.5 | 0.268 |
| CFT | 744.0 ± 142.4 | 801.9 ± 135.1 | 791.5 ± 76.7 | 0.196 |
| RMSSD (ms) | ||||
| Resting | 37.7 ± 16.8 | 28.9 ± 20.6a | 23.3 ± 17.5a | 0.049 |
| SCWT-c | 32.6 ± 16.2 | 24.4 ± 18.2a | 18.7 ± 16.1a | 0.039 |
| SCWT-ic | 34.6 ± 17.5 | 22.1 ± 16.9a | 19.4 ± 16.7a | 0.005 |
| CFT | 29.8 ± 13.9 | 23.1 ± 18.3a | 21.0 ± 17.9a | 0.029 |
| pNN50 (%) | ||||
| Resting | 18.4 ± 14.2 | 8.3 ± 12.4a | 3.8 ± 7.0a | 0.001 |
| SCWT-c | 14.4 ± 13.4 | 6.6 ± 11.5a | 4.2 ± 9.0a | 0.011 |
| SCWT-ic | 14.9 ± 13.3 | 5.5 ± 10.8a | 3.8 ± 9.2a | 0.002 |
| CFT | 12.6 ± 12.2 | 5.8 ± 10.5a | 3.9 ± 8.9a | 0.019 |
The values are shown as mean ± SD. RRI, R-R interval; SCWT-c, Stroop color word test with congruent; SCWT-ic, Stroop color word test with congruent; CFT, category fluency test; RMSSD, root mean square of the successive differences; pNN50, proportion of NN50 divided by the total number of NN (R-R) intervals. NN50 is the number of times successive heartbeat intervals exceed 50 ms.
ap < 0.05 compared to young adults, by one-way ANOVA with post-hoc Tukey test.