EFFECTS OF ESTROGEN AND PROGESTIN ON AORTIC SIZE AND COMPLIANCE IN POSTMENOPAUSAL WOMEN

OBJECTIVE: Our purpose was to determine whether sex steroids alter aor tic size and compliance in postmenopausal women. STUDY DESIGN: Twenty- six postmenopausal women were randomized to receive either conjugated estrogens 0.625 mg per day (group 1) or conjugated estrogens 0.625 mg per day and medroxyprogesterone 2.5 mg per day (group 2). Aortic cross -sectional area was measured by magnetic resonance imaging before and after 3 months of hormone therapy. RESULTS: Estradiol levels increased in both group 1 and group 2 (p < 0.0001). Ascending aortic cross-sect ional area increased from 439 +/- 7 mm(2) to 466 +/- 7 mm(2) in group 1 (p < 0.008) but was unchanged in group 2, Within the range of aortic pressures studied, no change in aortic compliance could be detected. CONCLUSION: Estrogen therapy in postmenopausal women was associated wi th an increase in aortic size; but this effect was not detectable with the addition of progestin. The potential antagonistic effect of proge stin on estrogen-induced aortic enlargement suggests that the favorabl e cardiovascular effects of postmenopausal estrogen therapy cannot be automatically extended to the combination estrogen-progestin.