Interrelationships Among Various Measures of Central Artery Stiffness

A number of different techniques and methodologies have been applied to quantify stiffness of arteries. Because measures of arterial stiffness differ in regards to measurement locations as well as properties, it is not clear how well these measures that are supposed to reflect the same arterial wall properties are related.

Interrelationships between different measures of arterial stiffness were evaluated in 50 apparently healthy subjects varying in age.

Significant relations ranging from mild to strong were observed among measures of arterial stiffness while some measures were not significantly associated. Cardio-ankle vascular index (CAVI) was significantly associated with carotid-femoral pulse wave velocity (cfPWV) and brachial-ankle pulse wave velocity (baPWV). Ultrasound-derived measures of arterial stiffness (e.g., compliance, distensibility) were weakly or not significantly related to pulse wave velocity (PWV) measures. The limits of agreement between each of arterial stiffness measures based on the Bland-Altman analyses indicate that there were close agreements (CI = 1.12-1.52) between CAVI, cfPWV, and baPWV. However, agreements between PWV measures and ultrasound-derived measures were mild to moderate. β-stiffness index demonstrated large 95% CIs with other measures. When associations between relative changes in various measures of arterial stiffness in response to isometric handgrip exercise were evaluated, the general trend of associations was similar to the relations observed at rest. β-stiffness index was not related to most measures of arterial stiffness.

These results suggest that the techniques used to assess arterial stiffness may not be interchangeable in clinical and research settings and that comparisons of findings obtained with different arterial stiffness measures should be conducted with caution.