title: A control systems approach to quantify wall shear stress normalization by flow-mediated dilation in the brachial artery.
abstract: Flow-mediated dilation is aimed at normalization of local wall shear stress under varying blood flow conditions. Blood flow velocity and vessel diameter are continuous and opposing influences that modulate wall shear stress. We derived an index FMDv to quantify wall shear stress normalization performance by flow-mediated dilation in the brachial artery. In 22 fasting presumed healthy men, we first assessed intra- and inter-session reproducibilities of two indices pFMDv and mFMDv, which consider the relative peak and relative mean hyperemic change in flow velocity, respectively. Second, utilizing oral glucose loading, we evaluated the tracking performance of both FMDv indices, in comparison with existing indices [i.e., the relative peak diameter increase (%FMD), the peak to baseline diameter ratio (Dpeak/Dbase), and the relative peak diameter increase normalized to the full area under the curve of blood flow velocity with hyperemia (FMD/shearAUC) or with area integrated to peak hyperemia (FMD/shearAUC_peak)]. Inter-session and intra-session reproducibilities for pFMDv, mFMDv and %FMD were comparable (intra-class correlation coefficients within 0.521-0.677 range). Both pFMDv and mFMDv showed more clearly a reduction after glucose loading (reduction of ~45%, p≤0.001) than the other indices (% given are relative reductions): %FMD (~11%, p≥0.074); Dpeak/Dbase (~11%, p≥0.074); FMD/shearAUC_peak (~20%, p≥0.016) and FMD/shearAUC (~38%, p≤0.038). Further analysis indicated that wall shear stress normalization under normal (fasting) conditions is already far from ideal (FMDv << 1), which (therefore) does not materially change with glucose loading. Our approach might be useful in intervention studies to detect intrinsic changes in shear stress normalization performance in conduit arteries.
authors.affiliation: Department of Biomedical Engineering, Maastricht University Medical Centre+, Maastricht, The Netherlands; Department of Radiology, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Mental Health and Neuroscience (MHeNS), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Frank C G
authors.initials: FC
authors.lastname: van Bussel
authors.affiliation: Department of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Nutrition, Toxicology and Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Bas C T
authors.initials: BC
authors.lastname: van Bussel
authors.affiliation: Department of Biomedical Engineering, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Cardiovascular Diseases (CARIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Arnold P G
authors.initials: AP
authors.lastname: Hoeks
authors.affiliation: Department of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Cardiovascular Diseases (CARIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Jos
authors.initials: J
authors.lastname: Op 't Roodt
authors.affiliation: Department of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Cardiovascular Diseases (CARIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Ronald M A
authors.initials: RM
authors.lastname: Henry
authors.affiliation: Department of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands; Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Cardiovascular Diseases (CARIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Isabel
authors.initials: I
authors.lastname: Ferreira
authors.affiliation: Department of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Cardiovascular Diseases (CARIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Floris H M
authors.initials: FH
authors.lastname: Vanmolkot
authors.affiliation: Department of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Cardiovascular Diseases (CARIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Casper G
authors.initials: CG
authors.lastname: Schalkwijk
authors.affiliation: Department of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Nutrition, Toxicology and Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Cardiovascular Diseases (CARIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Coen D A
authors.initials: CD
authors.lastname: Stehouwer
authors.affiliation: Department of Biomedical Engineering, Maastricht University Medical Centre+, Maastricht, The Netherlands; School for Cardiovascular Diseases (CARIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Koen D
authors.initials: KD
authors.lastname: Reesink
mesh_terms: D000293:Adolescent; D000328:Adult; D001775:Blood Circulation / Q000502:physiology*; D001783:Blood Flow Velocity; D001786:Blood Glucose / Q000378:metabolism; D001916:Brachial Artery / Q000502:physiology*; D005215:Fasting; D005951:Glucose Tolerance Test; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D013314:Stress, Mechanical; D014664:Vasodilation; D055815:Young Adult
chemical_list: D001786:Blood Glucose