TY - JOUR
T1 - Association beween resting heart rate, shear and flow-mediated dilation in healthy adults
AU - Fox, Brandon M.
AU - Brantley, Lucy
AU - White, Claire
AU - Seigler, Nichole
AU - Harris, Ryan A.
N1 - Publisher Copyright:
© 2014 The Authors.
PY - 2014
Y1 - 2014
N2 - Preclinical data have demonstrated that heart rate (HR) can directly impact vascular endothelial function, in part, through a shear-stress mechanism. This study sought to explore, in humans, the associations between resting heart rate and both shear and endothelial function assessed by flow-mediated dilation (FMD). The brachial artery FMD test was performed in 31 apparently healthy volunteers. Basal (B) and hyperaemic (H) shear were quantified in the following two ways using data from the FMD test: the traditional cumulative shear area under the curve up to peak dilation (Shearcum) method; and our novel method of shear summation (Shearsum), which accounts for HR by summing each individual cardiac cycle shear up to peak dilation. Data were grouped by tertiles based on resting HR as follows: low (LHR = 43-56 beats min-1; n = 10); middle (MHR = 58-68 beats min-1; n = 11); and high (HHR = 69-77 beats min-1; n = 10). Within the LHR group, both B-Shearcum and H-Shearcum were significantly higher (P < 0.001) than B-Shearsum and H-Shearsum, respectively, whereas in the HHR group B-Shearcum and H-Shearcum were significantly lower (P < 0.001) than B-Shearsum and H-Shearsum, respectively. The FMD in the LHR group (8.8 ± 0.8%) was significantly greater than that in both the MHR group (5.5 ± 0.8%; P = 0.009) and the HHR group (5.9 ± 0.8%; P = 0.024). These findings demonstrate the existence of a relationship between heart rate and both shear and endothelial function in humans. Moreover, these findings have implications for considering heart rate as an important physiological variable when quantifying shear and performing the FMD test.
AB - Preclinical data have demonstrated that heart rate (HR) can directly impact vascular endothelial function, in part, through a shear-stress mechanism. This study sought to explore, in humans, the associations between resting heart rate and both shear and endothelial function assessed by flow-mediated dilation (FMD). The brachial artery FMD test was performed in 31 apparently healthy volunteers. Basal (B) and hyperaemic (H) shear were quantified in the following two ways using data from the FMD test: the traditional cumulative shear area under the curve up to peak dilation (Shearcum) method; and our novel method of shear summation (Shearsum), which accounts for HR by summing each individual cardiac cycle shear up to peak dilation. Data were grouped by tertiles based on resting HR as follows: low (LHR = 43-56 beats min-1; n = 10); middle (MHR = 58-68 beats min-1; n = 11); and high (HHR = 69-77 beats min-1; n = 10). Within the LHR group, both B-Shearcum and H-Shearcum were significantly higher (P < 0.001) than B-Shearsum and H-Shearsum, respectively, whereas in the HHR group B-Shearcum and H-Shearcum were significantly lower (P < 0.001) than B-Shearsum and H-Shearsum, respectively. The FMD in the LHR group (8.8 ± 0.8%) was significantly greater than that in both the MHR group (5.5 ± 0.8%; P = 0.009) and the HHR group (5.9 ± 0.8%; P = 0.024). These findings demonstrate the existence of a relationship between heart rate and both shear and endothelial function in humans. Moreover, these findings have implications for considering heart rate as an important physiological variable when quantifying shear and performing the FMD test.
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U2 - 10.1113/expphysiol.2014.080960
DO - 10.1113/expphysiol.2014.080960
M3 - Article
C2 - 25037565
AN - SCOPUS:84908374502
SN - 0958-0670
VL - 99
SP - 1439
EP - 1448
JO - Experimental Physiology
JF - Experimental Physiology
IS - 10
ER -