PLASMA-LIPID AND LIPOPROTEIN EFFECTS OF TRANSDERMAL ADMINISTRATION OF ESTRADIOL AND ESTRADIOL NORETHISTERONE ACETATE

To evaluate the effect of transdermal sequential treatment with estradiol and estradiol/norethisterone acetate on lipoprotein metabolism, 25 postmenopausal women received treatment for 12 cycles of 4 weeks each (2 weeks estradiol 50 mug/day and 2 weeks a combined patch delivering norethisterone acetate 0.25 mg/day and estradiol 50 mug/day). Blood samples for lipoprotein analyses were drawn before treatment and in estrogen and combined phases in cycles 3 and 12. Plasma total cholesterol, low (LDL) and high (HDL) density lipoprotein were all significantly reduced in both estrogen and combined phases. Eighteen of the women continued the treatment for 36 cycles. In this group the HDL-cholesterol had returned to baseline values in combined phase in cycle 24. Plasma cholesterol and LDL-cholesterol values remained significantly reduced throughout the whole study compared to the pre-trial values. The present study by transdermal sequential hormonal treatment results in a lipid and lipoprotein pattern with reduced total cholesterol and LDL cholesterol in postmenopausal women.