Brachial artery hyperaemic blood flow velocity in relation to established indices of vascular function and global atherosclerosis

Background: Systolic to diastolic blood flow velocity (SDFV) ratio in the brachial artery recently proved to be related to cardiovascular risk and carotid atherosclerosis. We hypothesized that the SDFV ratio was related to established markers of vascular function and global atherosclerosis. Methods: Established markers of endothelial function in forearm resistance vessels, flow-mediated vasodilation and arterial stiffness were assessed in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study including 1016 individuals aged 70. Whole-body magnetic resonance angiography was performed in a random 306 of the participants. Atherosclerotic lesions were summarized in a total atherosclerotic score (TAS). Before and during hyperaemia of the brachial artery, systolic and diastolic blood flow velocities were measured by Doppler. Results: The SDFV ratio was positively related to endothelium-independent vasodilatation, while inverse relations were found to flow-mediated dilation, common carotid artery distensibility and the stroke volume to pulse pressure ratio. Endothelium-dependent vasodilatation and total peripheral resistance index were not significantly related to the SDFV ratio. The SDFV ratio (P = 0Æ015) and the blood flow increase (BFI) during hyperaemia (P = 0Æ020) were both significantly related to TAS after gender adjustment. When adjusted for the Framingham risk score, both the SDFV ratio (P = 0Æ057) and BFI (P = 0Æ078) lost somewhat in significance. Conclusion: The SDFV ratio was related to established markers of both vasodilation and arterial compliance, and to global atherosclerosis. Future larger studies have to evaluate whether the SDFV ratio is related to global atherosclerosis independently of traditional risk factors.