Gender differences in wall shearmediated brachial artery vasoconstriction and vasodilation
Jaime Levenson, MD*,a,
Franco Pessana, E. ENG ,
Jerome Gariepy, MDa,
Ricardo Armentano, PhD and
Alain Simon, MDa
a Centre de Médecine Préventive Cardiovasculaire, Institut National de la Santé et de la Recherche Médicale (INSERM), Hôpital Broussais, Paris, France
Favaloro University, Buenos Aires, Argentina

View larger version (30K):
[in a new window]
|
Figure 1 Representative tracings of brachial artery velocity profiles for one subject assessed by Doppler multigated velocimetry at baseline (left), during forearm occlusion at 180 s (center) and after 20 s of reactive hyperemia (right). Bold lines represent the mean value of at least 200 velocity profiles at each condition.
|
|

View larger version (11K):
[in a new window]
|
Figure 2 (Left) Measured diameter obtained by Doppler multigated velocimetry, as compared with true tube values. (Right) Difference in mean value between the measured diameter obtained by Doppler multigated velocimetry and the actual tube diameter value.
|
|

View larger version (24K):
[in a new window]
|
Figure 3 Time course of the entire duration of brachial wall shear rate and diameter measurements at baseline and during occlusion and reactive hyperemia in men and women.
|
|

View larger version (20K):
[in a new window]
|
Figure 4 (Left bars) Changes in brachial diameter during arterial occlusion at 3 min, normalized for changes in wall shear rate at the same time. (Right bars) Changes in diameter after 1-min release of arterial occlusion, normalized for the maximal changes in wall shear at 20 s. p < 0.01.
|
|

View larger version (18K):
[in a new window]
|
Figure 5 Scatterplot showing regression lines between brachial artery diameter and shear rate changes during the entire time course of the study (see Fig. 3). Each point for women and men corresponds to the mean percent change from baseline of the 5 measurements obtained during occlusion and the 10 measurements obtained after release of the occlusion. Solid circles represent men: y = 0.0734 x 3.964, r = 0.79, p < 0.01; open circles represent women: y = 0.1842 x +0.3064, r = 0.81, p < 0.01. Slope difference: p < 0.01. Note that the maximal increase in shear in men (282 ± 62%) and women (131 ± 28%) at 20 s is reached before the maximal increase in diameter. The exclusion of these points did not affect the significance of the regression.
|
|
|