Dose response effect of conjugated equine oestrogen on blood pressure in postmenopausal women with hypertension

Objective: This study was designed to compare with placebo the dose-response of conjugated equine oestrogen (CEE) on blood pressure in hypertensive postmenopausal women. Design and Methods: Fourteen postmenopausal women with grade 1-2 hypertension participated in the study which used a double-blind crossover design. There were four randomised treatment phases, each lasting 4 weeks. The four treatments were CEE 0.3 mg, CEE 0.625 mg, CEE 1.25 mg and placebo. Each subject also received non-blinded medroxyprogesterone acetate (MPA) 10 mg for the final 14 days of each 28-day treatment cycle. Clinic blood pressure was measured weekly with the mean values of weeks 3 and 4 of each phase used for analysis. Ambulatory blood pressure was performed in week 4 of each phase. Results: Compared with placebo, clinic systolic blood pressure was reduced in the CEE 0.3 mg and CEE 0.625 mg phases (p < 0.05) and clinic diastolic blood pressure was reduced in the CEE 0.625 mg phase (p < 0.05). There was no significant effect of CEE on ambulatory blood pressure, although the blood pressure pattern was similar to clinic measurements. Conclusion: In hypertensive postmenopausal women, daily CEE together with cyclical MPA has a variable effect on blood pressure depending on CEE dose. The "lower" and "middle" doses of CEE produced a small reduction in blood pressure which reached a nadir and tended to reverse with the "higher" CEE dose.