A novel noninvasive and simple method for assessment of endothelial function: Enclosed zone flow-mediated vasodilation (ezFMD) using an oscillation amplitude measurement

- We measured enclosed zone FMD by a new device using an oscillometric method.
- ezFMD significantly correlated with FMD measured.
- Classical cardiovascular risk factors were independent predictors of ezFMD.
- ezFMD is useful for determination of vascular response to reactive hyperemia.
- ezFMD is more simple and less bias than is measurement of conventional FMD.

BackgroundIt is clinically important to estimate the degree of endothelial dysfunction. Several methods have been used to assess endothelial function in humans. Recently, we developed a new noninvasive method for measurement of vascular response to reactive hyperemia in the brachial artery, named enclosed zone flow-mediated vasodilation (ezFMD). The purpose of this study was to determine the validity of ezFMD for assessment of endothelial function.Methods and resultsWe measured ezFMD by a new device using an oscillometric method and conventional FMD using ultrasonography in 306 subjects, including patients with hypertension, dyslipidemia, and diabetes mellitus (218 men and 88 women, 30 ± 16 yr). Univariate regression analysis revealed that ezFMD significantly correlated with age (r = −0.42, P < 0.0001), body mass index (r = −0.13, P = 0.028), systolic blood pressure (r = −0.15, P = 0.009), diastolic blood pressure (r = −0.14, P = 0.011), fasting glucose level (r = −0.27, P = 0.006), smoking (r = −0.21, P = 0.007) and baseline pulse wave amplitude (r = −0.51, P < 0.0001). ezFMD significantly correlated with conventional FMD (r = 0.34, P < 0.0001). Multiple regression analysis revealed that age (P = 0.002), body mass index (P = 0.013), systolic blood pressure (P = 0.009), smoking (P = 0.004) and baseline pulse wave amplitude (P < 0.001) were independent predictors of ezFMD.ConclusionsThese findings suggest that measurement of ezFMD, a novel noninvasive and simple method, may be useful for determination of vascular diameter response to reactive hyperemia. Since ezFMD is automatically measured by a device with an oscillometric method, measurement of ezFMD is easier and less biased than that of conventional FMD.