Lipids and antioxidative effects of estradiol and sequential norethisterone acetate treatment in a 3-month randomized controlled trial

Objective To determine the influence of hormone replacement therapy on serum lipids and antioxidative factors associated with the risk of coronary heart disease. Methods The effect of a sequential estradiol-norethisterone acetate regimen or placebo on lipid metabolism, antioxidative variables and fatty acid composition in serum was measured during the peak-estrogen phase in a randomized, double-blind, placebo-controlled study of 42 healthy postmenopausal women for 3 months. Results Active treatment significantly reduced lipoprotein(a) by 15% (p = 0.005, compared with placebo), low-density lipoprotein (LDL) cholesterol by 10% (p = 0.005) and the LDL cholesterol/high-density lipoprotein (HDL) cholesterol ratio by 11% (p = 0.016). Serum triglycerides increased by 21% (p = 0.045). No effect was observed on HDL cholesterol, on apolipoproteins apo A(1) or apo B, or on non-esterified fatty acids in serum. No treatment effect was seen in the proportions of monounsaturated and polyunsaturated fatty acids. The concentration of malondialdehyde in serum did not change with the estrogen-progestin treatment. Conclusions This sequential estrogen-progestin therapy has a beneficial effect on apolipoprotein(a) and LDL cholesterol, but no effect on non-esterified fatty acids or the level of lipid peroxidation products in serum.