Conjugated estrogen plus medroxyprogesterone does not impair blood rheological properties in hypertensive postmenopausal women

Abstract

Objectives Hypertension and estrogens are both prothrombotic. We used the microchannel method to investigate whether hormone replacement therapy (HRT) with conjugated equine estrogen (CEE) plus medroxyprogesterone acetate (MPA) affects blood flow through the microchannels in hypertensive postmenopausal women being treated with antihypertensive drugs and in normotensive postmenopausal women. Methods Sixty-two consecutive postmenopausal women were randomly assigned to a hypertensive HRT group ( n = 16), hypertensive control group ( n = 15), normotensive HRT group ( n = 16) and normotensive control group ( n = 15). Each HRT group received CEE 0.625 mg plus MPA 2.5 mg daily orally for 12 months. Both hypertensive groups were being treated with antihypertensive drugs before the study. Microvascular blood flow was assessed on the basis of blood passage time, the time required for 100 μl of whole blood to pass through a cylinder, was determined before and 12 months after the start of HRT by the microchannel method (micro channel array flow analyzer). Results CEE plus MPA therapy did not change blood passage time in any of the groups. Microscopic observation showed that the whole blood passed smoothly through the microchannels in every group. Conclusions CEE plus MPA therapy may not impair blood flow through the microchannels in hypertensive postmenopausal women receiving antihypertensive drugs or in normotensive postmenopausal women. However, administration of CEE plus MPA to postmenopausal women with hypertension warrants caution against the occurrence of thromboembolic events.