title: Influence of vascular dimension on gender difference in flow-dependent dilatation of peripheral conduit arteries.
abstract: To assess the influence of initial diameter on the gender difference in flow-dependent dilatation (FDD) of the conduit artery, we measured radial artery internal diameter (echotracking), flow (Doppler) and total blood viscosity in 24 healthy (25 +/- 0.8 yr) men and women during reactive hyperemia (RH) and during a gradual hand skin heating (SH). At baseline, mean diameter (men, 2.76 +/- 0.09 vs. women, 2.32 +/- 0.07 mm, P < 0.05), flow (men, 21 +/- 4 vs. women, 10 +/- 1 ml/min, P < 0.05), and blood viscosity (men, 4.13 +/- 0.07 vs. women, 3.92 +/- 0.13 cP, P < 0.05) were higher in men but mean shear stress (MSS) was not different between groups. During RH, the percent increase in diameter was lower in men (men, 9 +/- 1 vs. women, 13 +/- 1%, P < 0.05). This difference was suppressed after correction for baseline diameter. During SH, the increase in diameter with flow was higher in women (P < 0.01). However, the increase in MSS was higher in women because of their smaller diameter at each level of flow (P < 0.01) and there was no difference between groups for the increase in diameter at each level of MSS. These results demonstrate in a direct manner that initial diameter influences the magnitude of FDD of conduit arteries in humans by modifying the value of the arterial wall shear stress at each level of flow and support the interest of the heating method in presence of heterogeneous groups.
authors.affiliation: Department of Pharmacology, Institut National de la Santé et de la Recherche Médicale E9920, Institut Fédératif de Recherche Multidisciplinaire Sur les Peptides No. 23, Rouen University Hospital, 76031 Rouen, France. robinson.joannides@chu-rouen.fr
authors.forename: Robinson
authors.initials: R
authors.lastname: Joannides
authors.forename: Agathe
authors.initials: A
authors.lastname: Costentin
authors.forename: Michaela
authors.initials: M
authors.lastname: Iacob
authors.forename: Patricia
authors.initials: P
authors.lastname: Compagnon
authors.forename: Agnès
authors.initials: A
authors.lastname: Lahary
authors.forename: Christian
authors.initials: C
authors.lastname: Thuillez
mesh_terms: D000704:Analysis of Variance; D001783:Blood Flow Velocity; D001794:Blood Pressure; D015992:Body Mass Index; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006358:Hot Temperature; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D012039:Regional Blood Flow; D012044:Regression Analysis; D015203:Reproducibility of Results; D012727:Sex Characteristics; D012867:Skin / Q000098:blood supply*; D012881:Skin Temperature / Q000502:physiology*; D014463:Ultrasonography; D014664:Vasodilation / Q000502:physiology*