title: Relationship between augmentation index and flow-mediated vasodilation in the brachial artery.
abstract: Recent studies have shown that the augmentation index (AI) is a predictor of cardiovascular complications. Endothelial dysfunction is the initial step in the pathogenesis of atherosclerosis, which in turn can lead to cardiovascular complications. Endothelial function assessed by flow-mediated dilation (FMD) can serve as an independent predictor of cardiovascular events. However, there is little information on the relationship between AI and FMD in the human vasculature, and we therefore investigated this relationship in the present study. A total of 100 subjects (71 males and 29 females; age range, 22-88 years; mean age, 59 +/- 17 years), including 83 patients with cardiovascular diseases (e.g., atherosclerosis, hypertension, coronary heart disease, stroke and peripheral arterial disease) and 17 healthy subjects were enrolled. High-resolution ultrasonography (automated vessel-diameter measurements; eTRACKING system), a linear array transducer (13 MHz) and an arm holding device were used to measure the arterial diameter response to reactive hyperemia and sublingual nitroglycerine (NTG, 75 micrograms) in all subjects. AI measured using an automated device was significantly correlated with FMD (r = -0.38, p < 0.0001). There was no significant correlation between AI and vascular response to NTG. Multiple regression analysis showed that FMD was a significant independent predictor of AI (p < 0.05). These findings suggest that increase in arterial stiffness may be associated with grade of endothelial dysfunction and that AI may be an index of not only arterial stiffness but also endothelial function.
authors.affiliation: Department of Medicine and Molecular Science, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Soga
authors.forename: Shuji
authors.initials: S
authors.lastname: Nakamura
authors.forename: Kenji
authors.initials: K
authors.lastname: Nishioka
authors.forename: Takashi
authors.initials: T
authors.lastname: Umemura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Jitsuiki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hidaka
authors.forename: Hiroki
authors.initials: H
authors.lastname: Teragawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takemoto
authors.forename: Chikara
authors.initials: C
authors.lastname: Goto
authors.forename: Masao
authors.initials: M
authors.lastname: Yoshizumi
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
authors.forename: Yukihito
authors.initials: Y
authors.lastname: Higashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001916:Brachial Artery / Q000503:physiopathology*; D002318:Cardiovascular Diseases / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017534:Radial Artery / Q000503:physiopathology*; D014664:Vasodilation