Local Shear Stress and Brachial Artery Flow-Mediated Dilation

作者：Gary F. Mitchell, Helen Parise, Joseph A. Vita, Martin G. Larson, Elaine Warner, John F. Keaney, Michelle J. Keyes, Daniel Levy, Ramachandran Srini Vasan, Emelia J. Benjamin · 发表于：Hypertension · 年份：2004 · DOI：10.1161/01.hyp.0000137305.77635.68 · 被引用次数：376 · 研究领域：Vascular Procedures and Complications、Cardiac Imaging and Diagnostics、Peripheral Artery Disease Management

Endothelium-dependent flow-mediated dilation is a homeostatic response to short-term increases in local shear stress. Flow-mediated dilation of the brachial artery in response to postischemic reactive hyperemia is impaired in patients with cardiovascular disease risk factors and may reflect local endothelial dysfunction in the brachial artery. However, previous studies have largely neglected the effect of risk factors on evoked shear stress, which is the stimulus for dilation. We evaluated brachial artery percent dilation and evoked diastolic shear stress during reactive hyperemia using high-resolution ultrasound and Doppler in 2045 participants (1107 women, mean age 61 years) in the Framingham Offspring Study. In age- and sex-adjusted models, baseline and hyperemic shear stress were related to brachial artery percent dilation. In stepwise multivariable analyses examining clinical correlates of percent dilation (without shear stress in the model), age, sex, mean arterial pressure, pulse pressure, heart rate, body mass index, lipid medication use, and hormone replacement therapy were related to percent dilation (R2=0.189; P<0.001). When hyperemic shear stress was incorporated, the overall R2 improved (R2=0.335; P<0.001), but relationships between risk factors and percent dilation were attenuated (age and mean arterial pressure) or no longer significant (all others). In contrast, risk factors were related to baseline and hyperemic shear stress in multivariable analyses. Evoked ...