Objective: This study was designed in order to evaluate the effect of conjugated equine estrogens (CEE) on internal carotid and middle cerebral artery blood flow in postmenopausal women.
Design: Thirty-four healthy postmenopausal women with intact uteri were randomly divided into two groups of 17 subjects each. The first group was treated for 24 weeks with continuous CEE medication (0.625 mg daily) and cyclical supplementations of 5 mg/day of medrogestone acetate, given on the last 12 days of every 4-week period (Prempak, Wyeth, Italy). The second group received no treatment. The pulsatility indices (PI) of both the internal carotid artery and middle cerebral artery were measured.
Results: In the treated group, the PI of the interior carotid artery and MCA was reduced from respectively 0.736 (0.016) and 0.745 (0.009) at baseline, to 0.669 (0.021) and 0.670 (0.011) after 24 weeks (p = 0.01); in the control group, the PI values remained unchanged. The between-group difference for both arteries was significant (p < 0.01).
Conclusions: The administration of CEE with cyclical medrogestone supplementation to postmenopausal women induces a statistically significant reduction in the PI of cerebral arteries.