Volume Elastic Modulus, Vascular Function, and Vascular Structure in Patients with Cardiovascular Risk Factors.

AIMS: Volume elastic modulus (VE), an index of arterial elasticity, and arterial diameter of the brachial artery can be automatically measured by a newly developed oscillometric device. We investigated the associations of VE with flow-mediated vasodilation (FMD), an index of endothelium-dependent vasodilation, nitroglycerine-induced vasodilation (NID), an index of endothelium-independent vasodilation, and intima-media thickness (IMT) of the brachial artery and association of oscillometrically measured brachial artery diameter with ultrasonographically measured brachial artery diameter in patients with cardiovascular risk factors.

METHODS

Oscillometric measurements of VE and brachial artery diameter and ultrasound measurements of brachial artery diameter, FMD, NID, and IMT of the brachial artery were performed in 50 patients with cardiovascular risk factors.

RESULTS

The mean values were 2.1±0.4 mmHg/% for VE, 0.31±0.05 mm for brachial IMT, 4.48±0.70 mm for oscillometric brachial artery diameter, and 4.30±0.55 mm for ultrasound brachial artery diameter. VE significantly correlated with brachial IMT (r=0.51, P＜0.001), whereas there was no significant correlation of VE with FMD (r=-0.08, P=0.58) or NID (r=0.07, P=0.61). Multivariate analysis revealed that VE was significantly associated with brachial IMT (β=0.33, P=0.04). Oscillometric brachial artery diameter significantly correlated with ultrasound brachial artery diameter (r=0.79, P＜0.001). The Bland-Altman plot showed good agreement between oscillometric brachial artery diameter and ultrasound brachial artery diameter (mean difference, -0.17 mm; limits of agreement, -1.03 mm to 0.69 mm).

CONCLUSIONS

In patients with cardiovascular risk factors, VE may represent atherosclerotic structural alterations of the vascular wall but not vascular function. The accuracy of oscillometric measurement of brachial artery diameter is acceptable.