Observations of time-based measures of flow-mediated dilation of forearm conduit arteries: Implications for the accurate assessment of endothelial function

Andrew Liuni, Mary Clare Luca, Monica Lisi, Saverio Dragoni, Giuseppe Di Stolfo, Justin A. Mariani, Amar Uxa, Tommaso Gori, John D. Parker

Research output: Contribution to journalArticlepeer-review

Abstract

Endothelium-dependent flow-mediated dilation (FMD) is measured as the increase in diameter of a conduit artery in response to reactive hyperemia, assessed either at a fixed time point [usually 60-s post-cuff deflation (FMD60)] or as the maximal dilation during a 5-min continuous, ECG-gated, measurement (FMDmax-cont). Preliminary evidence suggests that the time between reactive hyperemia and peak dilation (time to FMD max) may provide an additional index of endothelial health. We measured FMDmax-cont, FMD60, and time to FMDmax in 30 young healthy volunteers, 22 healthy middle-aged adults, 16 smokers, 23 patients with hypertension, 40 patients with coronary artery disease, and 22 patients with heart failure. As previously reported, FMDmax-cont was similar in healthy cohorts and was significantly blunted in smokers and all patient groups, whereas FMD60 was significantly blunted only in heart failure patients. There was a wide within-group variability between measures of time to FMDmax with no significant difference between normal and patient groups. Intra-arterial infusion of the nitric oxide synthase inhibitor Nω-monomethyl-L-arginine in eight healthy subjects resulted in a blunting of FMDmax-cont (P <0.001) and FMD60 (P = 0.02) but not time to FMDmax. Both FMDmax-cont and FMD60 demonstrated good repeatability in 30 young healthy volunteers studied on two separate occasions (P <0.01 for both), whereas time to FMDmax varied widely between visits (P = not significant). In conclusion, although time to FMDmax does not appear to be a useful adjunctive measure of endothelial health, the use of continuous diameter measurements provides important data in the study of endothelial function in healthy subjects and patients with cardiovascular disease.

Original languageEnglish
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume299
Issue number3
DOIs
Publication statusPublished - Sep 2010

Keywords

  • Arterial diameter
  • Endothelium
  • Flow-mediated dilation
  • Time to peak dilation
  • Vascular physiology

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)
  • Cardiology and Cardiovascular Medicine
  • Medicine(all)

Fingerprint

Dive into the research topics of 'Observations of time-based measures of flow-mediated dilation of forearm conduit arteries: Implications for the accurate assessment of endothelial function'. Together they form a unique fingerprint.

Cite this