[Show abstract][Hide abstract] ABSTRACT: Flow-mediated vasodilatation of the brachial artery (FMD) is a marker which is related to endothelial nitric oxide bioavailability. Commercially available ultrasound machines equipped with online computer-assisted semi-automatic analysis software to measure FMD have recently become available in Japan. These devices enable more convenient examination, enhanced reproducibility of FMD measurement, and a shortened examination time. Using such devices, in the present multicenter prospective study we propose to: 1) establish standardized FMD values and determine the annual rates of FMD change in healthy subjects; 2) confirm the predictive value of FMD for future cardiovascular events in Japanese subjects; 3) evaluate the potential usefulness of a multimarker strategy, including measurements of FMD, pulse-wave velocity (PWV), ankle-brachial pressure index, biochemical markers, and proteomic biomarkers obtained by mass spectroscopic analysis to assess the prognosis of subjects with coronary artery disease; and 4) clarify the usefulness of FMD measurement to predict the rate of progression of carotid atherosclerosis, arterial stiffness and microalbuminuria in subjects with hypertension or diabetes mellitus. In total, we estimate that approximately 4000 Japanese subjects in 3 different study groups will eventually be enrolled in this prospective observational investigation. We anticipate that the present study will provide important evidence for the usefulness of FMD measurement in the risk stratification for cardiovascular disease.
International Heart Journal 07/2012; 53(3):170-5. DOI:10.1536/ihj.53.170 · 1.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We evaluated the relationship of the severity of hyperuricemia and the flow-mediated vasodilatation of the brachial artery (FMD) in patients with and without the metabolic syndrome (MetS).
In a cross-sectional study, FMD was obtained in 2,732 Japanese healthy men (49 ± 8 years) who had no cardiovascular (CV) disease and were not on any medication for CV risk factors. MetS was defined according to Japanese criteria, and serum uric acid (UA) levels in the upper half of the fifth (highest) quintile range were defined as severe hyperuricemia, whereas those in the lower half of this quintile range were defined as mild hyperuricemia.
Overall, the adjusted values of FMD were lower in the subjects with MetS (5.6 ± 0.1%; n = 413) than in those without MetS (6.2 ± 0.1%; n = 2,319) (P < 0.01). Among the subjects without MetS, the adjusted values of FMD were lower in both the subgroups with mild hyperuricemia and severe hyperuricemia than in the subgroup without hyperuricemia. On the contrary, among the subjects with MetS, the adjusted value of FMD was lower only in the subgroup with severe hyperuricemia (4.8 ± 0.3%) as compared with that in the group without hyperuricemia (5.7 ± 0.2%) (P < 0.05).
In middle-aged healthy Japanese men without MetS, not only severe, but also mild hyperuricemia may be a significant independent risk factor for endothelial dysfunction in subjects without MetS, whereas only severe hyperuricemia (but not mild hyperuricemia) appeared to exacerbate endothelial dysfunction in similar subjects with MetS.
American Journal of Hypertension 07/2011; 24(7):770-4. DOI:10.1038/ajh.2011.55 · 2.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Vascular endothelial dysfunction represents an initial step of "vascular failure," which we have recently proposed as a comprehensive syndrome of failed vascular functions that extends from risk factors to established atherosclerotic disease. The early detection of vascular failure is essential in order to appropriately intervene and prevent its progression. Many efforts have been made to assess vascular endothelial function, and one of the most promising methods is the measurement of endothelium-dependent flow-mediated vasodilation (FMD) using high-frequency ultrasonographic imaging and transient occlusion of the brachial artery. The reactive hyperemia caused by the transient brachial arterial occlusion induces the release of local nitric oxide, resulting in vasodilation that can be quantified as an index of vasomotor function. The noninvasive nature of this technique allows repeated measurements over time to study the effectiveness of various interventions that may affect vascular health. Although there are technical and interpretive limitations of this technique, FMD-guided therapeutic approaches for vascular failure should contribute to the improvement of cardiovascular mortality and morbidity.
Hypertension Research 01/2009; 31(12):2105-13. DOI:10.1291/hypres.31.2105 · 2.66 Impact Factor