P17 Comparisons of Carotid-femoral Pulse Wave Velocity Obtained from the Surface-distance Measurement and from the Population-derived Distance Formula: Associations with Macro- and Microvascular Alterations in Older Adults

Inaccurate determination of arterial path-length by surface-distance (SD) measurement is an inherent source of error in calculating carotid-femoral pulse wave velocity (CFPWV). A recent development in calculating arterial path-length by a simple distance formula (DF) for CFPWV has been shown to not only remove intercentre measurement variability but also strengthen the association between CFPWV and traditional cardiovascular risk factors [1]. We determined whether the association of macro- and microvascular alterations with CFPWV derived from the distance formula (CFPWV-DF) would be stronger than that with CFPWV derived from the surface-distance measurement (CFPWV-SD). CFPWV-DF and CFPWV-SD were obtained from 489 older adults (67.2 ± 8.8 yrs, 154 F, 244 CVD). Macrovascular [carotid lumen diameter (LD), carotid inter-adventitial diameter (IAD), carotid intima-media thickness (IMT), carotid total plaque area, and ankle-brachial pressure index] and microvascular [reactive hyperaemia index and urinary albumin-creatinine ratio (UACR)] parameters were also obtained. CFPWV-DF was significantly lower than CFPWV-SD (9.27 ± 2.38 vs 9.88 ± 2.55 m/s, p < 0.001), which resulted from a longer arterial path-length estimated by SD than DF (495.4 ± 44.8 vs 465.3 ± 20.6 mm, p < 0.001). The significant associations observed between CFPWV-SD and LD (r = 0.264), IAD (r = 0.303), and IMT (r = 0.165) were similarly observed between CFPWV-DF and LD (r = 0.253), IAD (r = 0.303), and IMT (r = 0.183, all p < 0.001). This was also the case with UACR (r = 0.163 and r = 0.141, both p = 0.001). Other parameters did not show any association in either CFPWV. The association of macro- and microvascular alterations with CFPWV-DF was not stronger than that with CFPWV-SD, suggesting that arterial path-length determination methods may not influence interactions between vascular biomarkers and CFPWV.