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Reliability of low‐flow vasoreactivity in the brachial artery of adolescents
Author(s) -
Kranen Sascha H.,
Bond Bert,
Williams Craig A.,
Barker Alan R.
Publication year - 2018
Publication title -
journal of clinical ultrasound
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.272
H-Index - 61
eISSN - 1097-0096
pISSN - 0091-2751
DOI - 10.1002/jcu.22664
Subject(s) - medicine , brachial artery , vasoconstriction , constriction , cardiology , vasodilation , coefficient of variation , blood pressure , statistics , mathematics
Purpose Macrovascular endothelial function is commonly assessed using flow‐mediated dilation (FMD) and is nitric oxide (NO) dependent. However, the vasoreactivity to low flow during the FMD protocol may complement FMD interpretation. This study aimed to investigate in adolescents: (1) the day‐to‐day reliability of low‐flow‐mediated constriction (L‐FMC) and composite vessel reactivity (CVR); and (2) the relationship between L‐FMC and FMD. Methods A retrospective analysis of data on 27 adolescents (14.3 ± 0.6 year, 12 males) was performed. Participants had two repeat measures, on separate days, of macrovascular function using high‐resolution ultrasound for assessment of L‐FMC, FMD, and CVR. Results On average, the L‐FMC response was vasoconstriction on both days (−0.59 ± 2.22% and −0.16 ± 1.50%, respectively). In contrast, an inconsistent response to low flow (vasoconstriction, dilation, or no change) was observed on an individual level. Cohen's Kappa revealed poor agreement for classifying the L‐FMC measurement between visits ( k = 0.04, P > .05). Assessment of the actual vessel diameter was robust with a coefficient of variation of 1.7% (baseline and peak) and 2.7% (low‐flow). The between‐day correlation coefficient between measures was r = .18, r = .96 and r = .52 for L‐FMC, FMD, and CVR, respectively. No significant correlation between FMD and L‐FMC was observed for either visit ( r = −.06 and r = −.07, respectively; P > .05). Conclusion In adolescents, the low‐flow vasoreactivity is inconsistent between days. Whereas the actual vessel diameter is reproducible, the measurement of L‐FMC and CVR has poor between‐day reliability compared to FMD. Finally, L‐FMC, and FMD are not significantly correlated.