OBJECTIVES: Our aim was to analyze flow-mediated dilation (FMD) time-course in response to forearm occlusion in the clinical setting. METHODS AND RESULTS: In 50 asymptomatic subjects, monitoring software measuring continuous beat-to-beat change in brachial artery diameter was used to determine FMD magnitude in percentage change in peak diameter from baseline (FMD-DeltaD), time to peak diameter after occlusion release (FMD-t(peak)), integrated FMD response calculated as area under dilation curve (FMD-AUC), maximum FMD rate calculated as maximal slope of dilation (FMD-MDR). FMD-DeltaD and FMD-MDR correlated positively with peak wall shear stress (P < 0.05, P < 0.01). FMD-MDR correlated negatively with age (P < 0.001), Framingham risk score (P < 0.01) and carotid intima-media thickness (P < 0.05), while FMD-DeltaD correlated negatively with Framingham risk score only (P < 0.01). After adjustment, all these correlations were independent of antihypertensive, lipid-lowering and antidiabetic therapies. All but that of FMD-MDR with intima-media thickness were also found in a subgroup of 29 untreated subjects and in a subgroup of 24 untreated and low-risk (FRS < 10%) subjects. FMD-t(peak) and FMD-AUC were not associated with shear stimulus, Framingham risk score, and intima-media thickness. CONCLUSION: The kinetics of dilation (maximum rate) seem more sensitive than their magnitude in assessing FMD performance and its determinants.
OBJECTIVES: Our aim was to analyze flow-mediated dilation (FMD) time-course in response to forearm occlusion in the clinical setting. METHODS AND RESULTS: In 50 asymptomatic subjects, monitoring software measuring continuous beat-to-beat change in brachial artery diameter was used to determine FMD magnitude in percentage change in peak diameter from baseline (FMD-DeltaD), time to peak diameter after occlusion release (FMD-t(peak)), integrated FMD response calculated as area under dilation curve (FMD-AUC), maximum FMD rate calculated as maximal slope of dilation (FMD-MDR). FMD-DeltaD and FMD-MDR correlated positively with peak wall shear stress (P < 0.05, P < 0.01). FMD-MDR correlated negatively with age (P < 0.001), Framingham risk score (P < 0.01) and carotid intima-media thickness (P < 0.05), while FMD-DeltaD correlated negatively with Framingham risk score only (P < 0.01). After adjustment, all these correlations were independent of antihypertensive, lipid-lowering and antidiabetic therapies. All but that of FMD-MDR with intima-media thickness were also found in a subgroup of 29 untreated subjects and in a subgroup of 24 untreated and low-risk (FRS < 10%) subjects. FMD-t(peak) and FMD-AUC were not associated with shear stimulus, Framingham risk score, and intima-media thickness. CONCLUSION: The kinetics of dilation (maximum rate) seem more sensitive than their magnitude in assessing FMD performance and its determinants.
Authors: Dick H J Thijssen; Mark A Black; Kyra E Pyke; Jaume Padilla; Greg Atkinson; Ryan A Harris; Beth Parker; Michael E Widlansky; Michael E Tschakovsky; Daniel J Green Journal: Am J Physiol Heart Circ Physiol Date: 2010-10-15 Impact factor: 4.733
Authors: Bethany Barone Gibbs; Devon A Dobrosielski; Michael Lima; Susanne Bonekamp; Kerry J Stewart; Jeanne M Clark Journal: Vasc Med Date: 2011-06-27 Impact factor: 3.239
Authors: Dick H J Thijssen; Lauren M Bullens; Marieke M van Bemmel; Ellen A Dawson; Nicola Hopkins; Toni M Tinken; Mark A Black; Maria T E Hopman; N Timothy Cable; Daniel J Green Journal: Am J Physiol Heart Circ Physiol Date: 2008-11-21 Impact factor: 4.733