Table 1. Descriptive data of included patients according to heart-rate-variability (HRV).
| Variables | SDNN ≤ 8 | SDNN > 8 | p | RMSSD ≤ 8 | RMSSD > 8 | p |
|---|---|---|---|---|---|---|
| N | 142 | 129 | 147 | 124 | ||
| Age, years* | 68 [59–75] | 71 [60–79] | 0.106 | 66 [57–73] | 72 [62–81] | <0.001 |
| Sex, n (%) | 0.874 | 0.508 | ||||
| Women | 57 (40.1) | 53 (41.1) | 57 (38.8) | 53 (42.7) | ||
| Men | 85 (59.9) | 76 (58.9) | 90 (61.2) | 71 (57.3) | ||
| Comorbidities, n (%) | ||||||
| Chronic heart disease | 37 (27.6) | 36 (30.3) | 0.644 | 28 (20.0) | 45 (39.8) | 0.001 |
| Hypertension | 70 (51.1) | 62 (49.6) | 0.809 | 63 (44.4) | 69 (55.6) | 0.034 |
| Obesity | 50 (37.0) | 34 (27.6) | 0.108 | 53 (37.6) | 31 (26.5) | 0.058 |
| Diabetes | 21 (16.9) | 20 (17.7) | 0.877 | 24 (17.9) | 17 (16.5) | 0.777 |
* Non normal-distributed data presented as median with interquartile range.
Note: SDNN = standard deviation of normal to normal heartbeat intervals; RMSSD = root mean square of successive differences between adjacent heartbeats. Both SDNN and RMSSD cut-offs are in msec.