Associations between noninvasive upper- and lower-limb vascular function assessments: extending the evidence to young women

Abstract

Brachial artery (BA) flow-mediated dilation (FMD) is a well-established measure of peripheral vascular function prognostic of future cardiovascular events. The vasodilatory response to FMD (FMD%) reflects upper-limb conduit artery function, whereas reactive hyperemia (RH) following cuff-occlusion release reflects upper-limb resistance artery function. Comparatively, passive leg movement (PLM) is a newer, increasingly utilized assessment of lower-limb resistance artery function. To increase its clinical utility, PLM-induced leg blood flow (LBF) responses have been compared with hemodynamic responses to FMD, but only in men. Therefore, the purpose of this study was to retrospectively compare LBF responses to FMD% and RH responses in women. We hypothesized that LBF responses would be positively associated with both FMD% and RH, but to a greater extent with RH. FMD and PLM were performed on 72 women (23 ± 4 yr). Arterial diameter and blood velocity were assessed using Doppler ultrasound. Pearson correlation coefficients were used to evaluate associations. Measures of resistance artery function were weakly positively associated: change in BA blood flow ΔBABF and ΔLBF (r = 0.33, P < 0.01), BABF area under the curve (BABF AUC) and LBF AUC (r = 0.33, P < 0.01), and BABF_peak and LBF_peak (r = 0.37, P < 0.01). However, FMD% was not associated with any index of PLM (all P > 0.30). In women, indices of resistance artery function in the upper- and lower limbs were positively associated. However, contrary to the previous work in men, upper-limb conduit artery function was not associated with lower-limb resistance artery function suggesting these assessments capture different aspects of vascular function and should not be used interchangeably in women.NEW & NOTEWORTHY Upper- and lower-limb indices of resistance artery function are positively associated in young women when assessed by reactive hyperemia following brachial artery flow-mediated dilation (FMD) cuff-occlusion release and leg blood flow responses to passive leg movement (PLM), respectively. However, despite previous data demonstrating a positive association between upper-limb conduit artery function assessed by FMD and lower-limb resistance artery function assessed by PLM in young men, these measures do not appear to be related in young women.

Keywords: conduit artery function; flow-mediated dilation; passive leg movement; resistance artery function; vascular function.

Graphical abstract

Figure 1.

Associations between indices of upper and lower limb resistance artery function as assessed by RH following FMD occlusion-cuff release and leg blood flow responses to PLM, respectively [number of participants (n) = 72 women]. Associations were evaluated using Pearson’s correlation coefficients. The association between the change in brachial artery blood flow (ΔBABF) and the change in leg blood flow from baseline to peak (ΔLBF; A). The association between brachial artery blood flow area under the curve (BABF AUC) and leg blood flow area under the curve (LBF AUC; B). The association between peak brachial artery blood flow (BABF_peak) and peak leg blood flow (LBF_peak; C). P values in bold font indicate significance. AUC, area under the curve; BABF, brachial artery blood flow; CI, confidence interval; FMD, flow-mediated dilation; LBF, leg blood flow; PLM, passive leg movement; r, Pearson correlation coefficient, RH, reactive hyperemia.