The Effect of Hemorheologic Factors on Middle Cerebral Artery Blood Flow Velocity in Young Individuals

Analysis of the effect of hemorheologic factors on middle cerebral artery (MCA) blood flow velocity in 55 healthy individuals aged 18 to 30 years demonstrated an inverse association between mean MCA blood flow velocity and hematocrit (r = -0.27, p < 0.05). This association was largely explained by the effect of whole-blood viscosity. Neither fibrinogen concentration nor plasma viscosity were significantly associated with MCA blood flow velocity in this group; this lack of a fibrinogen association is in contrast to results previously obtained in elderly individuals where an inverse association was observed. These findings thus demonstrate age-dependent differences in the relationship between fibrinogen and MCA blood flow velocity.