Sex-related differences in acetozolamide-induced cerebral vasomotor reactivity

Background and Purpose Cerebral vasomotor reactivity can easily be assessed reliably by measuring vasodilatory response to acetazolamide by transcranial Doppler sonography, The aim of this study was to confirm the hypothesis that female sex is associated with an increased cerebrovascular flow reserve. Methods Blood flow velocity of the middle cerebral artery was measured by transcranial Doppler sonography in 36 healthy sex- and age-matched subjects. After the initial blood flow velocities were recorded, the subjects received 14.3 mg/kg body wt acetazolamide, ie, 1 g/70 kg, intravenously. The measurements were repeatedly performed at 5-minute intervals starting 10 minutes after injection and lasting for 30 minutes. The highest measured flow velocities were used for further analysis. Results In both groups mean blood How velocity increased significantly after acetazolamide (women, from 60.2+/-12.5 to 89.9+/-14.4 cm/s, P<.006: men, from 54.5+/-18.8 to 75.7+/-24.5 cm/s, P<.02). The difference in mean blood flew velocity after acetazolamide between groups of women and men was statistically significant (P<.02). Conclusions Female subjects show an increased vasodilatory response to the acetazolamide test compared with men.