Effects of progestogen on lipids, lipoproteins and apolipoproteins during transdermal estrogen replacement therapy with and without medroxyprogesterone acetate.

OBJECTIVE

To assess whether the effects on plasma lipids and lipoproteins after oophorectomy differ in patients who receive transdermal estrogen replacement therapy (ERT) with and without progestin.

STUDY DESIGN

Twenty-five healthy, normal-weight, regularly menstruating women who underwent hysterectomy and bilateral oophorectomy for benign diseases received, for one year, transdermal therapeutic systems containing estradiol with daily delivery of 50 micrograms cyclically for 24 days per month plus 2.5 mg/d of oral medroxyprogesterone acetate (MPA) sequentially for the last 12 days of each cycle. After the first year the patients ceased to take MPA. We determined the levels of cholesterol (CHOL), high density lipoprotein (HDL)-CHOL, low density lipoprotein (LDL)-CHOL, triglycerides (TG) and apolipoproteins (apo) A-I and B prior to oophorectomy, one month after surgery and during the 6th and 12th months on estrogen plus progestogen substitution and during the 18th and 24th months without progestogen addition.

RESULTS

After oophorectomy, the patients showed increases in LDL, apo-B and atherogenic index, whereas after hormone replacement therapy the patients exhibited falls in plasma LDL, apo-B and atherogenic index and increases in HDL and apo A-I. No significant changes in total CHOL were observed after surgery or treatment, and TG were decreased. Plasma levels of lipids and lipoproteins during estrogen replacement therapy (ERT) without MPA were not significantly different from those observed during ERT plus MPA.

CONCLUSION

Changes in lipids induced by transdermal ERT were not affected by low doses of MPA.