[Lipoprotein metabolism in menopause. Effect of hormonal substitution therapy]

Oral administration of conjugated estrogens, estradiol valerate and micronized estradiol--but not the percutaneous application--in the postmenopause modifies the plasmic lipoprotein profile by lowering, dose-dependently, LDL and elevating HDL (HDL2). In parallel, the cardiovascular mortality is decreased by 50-66%, with smokers also benefiting to the same extent. On account of the increased risk for endometrial carcinoma associated with postmenopausal estrogen monotherapy, combination with a lowest-dose gestagen is imperative. However, the very numerous synthetic gestagens can antagonize the favorable effects of the estrogen on lipoprotein metabolism. This applies in particular to the gestagens of the 19-nortestosterone type, such as norethisterone acetate and, in particular, levonorgestrel, but less so the 17-hydroxyprogesterone derivatives medroxyprogesterone acetate and medrogestone with their very low androgenic effect.