Hormone replacement therapy: lipid responses to continuous combined oestrogen and progestogen versus oestrogen monotherapy

Abstract

Fifty-five postmenopausal women with climacteric complaints were randomly assigned to treatment with either 2 mg oestradiol valerate (E 2V) (cyclic regimen: 21 days of treatment followed by a 7-day treatment-free interval), or 2 mg E 2V combined with 1 mg cyproterone acetate (E 2V + CPA) daily, over a 6-month period. Treatment was by the oral route in both cases. The aim was to compare the influence of these two hormone replacement therapy regimens on lipid metabolism. Blood samples were obtained before and after 1 and 6 months of treatment. Serum was analyzed for total cholesterol (TC), high-density lipoproteins (HDL), apolipoproteins A1 and B and triglycerides. The low-density lipoprotein (LDL) concentrations were derived by calculation. All parameters were evaluated in terms of mean ± S.D. There was no significant difference in the response of the blood lipids to the two treatments, as assessed by analysis of variance ( P > 0.05). Serum levels of TC were found to have fallen after month 1 and 6 by 5.3 and 5.6%, respectively, during E 2V treatment and by 2.4 and 0.2% during E 2V + CPA treatment. Serum HDL levels had increased after months 1 and 6 by 9.7 and 5.2%, respectively, in the E 2V group and by 6.9 and 2% in the E 2V + CPA group, which was also confirmed by the increase in apolipoprotein A1 levels. There was, however, a borderline increase in LDL and apolipoprotein B in the E 2V + CPA group. Serum triglycerides were reduced and serum levels of SHBG increased during treatment in both groups. We conclude that the continuous addition of 1 mg CPA does not have a significant influence on lipids or lipoproteins in post-menopausal women. However, there is a need to collect further data to determine whether or not continuous addition of low-dose CPA affects lipid metabolism over a longer period.