| Risk category | Puls wave velocity (PWV) |
| |
| I | Optimal | PWV < 7.0 ms−1 | No signs of aortic stiffness |
| II | Normal | 7.0 < PWV < 9.7 ms−1 | No signs of aortic stiffness |
| III | Increased | 9.7 < PWV < 12.0 ms−1 | Signs of aortic stiffness |
| IV | Abnormal | PWV > 12.0 ms−1 | Clear signs of aortic stiffness |