Combined oestrogen-progestin replacement therapy prevents atherosclerosis in postmenopausal women

The incidence of atherosclerotic plaques in the aorta and in the carotid and iliac arteries was investigated using high resolution B-mode ultrasonography in 40 postmenopausal women using sequentially combined oestradiol valerate 2 mg--levonorgestrel 0.25 mg replacement therapy. In addition, serum lipid, lipoprotein and apolipoprotein levels were measured. Similar studies were performed for 40 postmenopausal women using oestradiol valerate alone and for 40 women who had never used hormone replacement therapy (HRT). Ultrasonographically observed atherosclerotic plaques were less common (P = 0.011) in oestradiol valerate--levonorgestrel users than in women without HRT. More than three atherosclerotic plaques were observed in 62% of the women without HRT but only in 30% of the women using combined therapy (P = 0.003). The total number of plaques did not differ between the two hormone using groups. The mean serum triglyceride, total cholesterol and apolipoprotein B levels were lowest in oestradiol valerate--levonorgestrel users when compared with those of women with oestradiol valerate monotherapy and those of women without HRT. Combined oestradiol valerate--levonorgestrel replacement therapy, like oestradiol valerate monotherapy, prevents the progression of atherosclerosis in postmenopausal women. The lipid patterns were not adversely affected by the addition of the androgenic levonorgestrel.