Effect of a new cyclical sequential postmenopausal HRT on lipoprotein, apoprotein and thrombophilia profile

We examined the changes in lipoprotein, apoprotein, and thrombophilia profile in postmenopausal women using a new cyclical sequential combined HRT regimen. The study medication consisted of two tablets of Hormonin (oestriol 0.27 mg, oestrone 1.4 mg and oestradiol 0.6 mg), daily and norethisterone (1 mg) BP (Shire Developments) for the last 12 days of every 28 day cycle. Serial fasting blood samples were collected at the beginning of the study and, thereafter, at 3-monthly intervals for 1 year, each patient acting as her own control. Thirty-five healthy postmenopausal women completed 1 year of follow-up and had a complete set of fasting blood samples. The lipid profile; total cholesterol, triglycerides, HDL, LDL, Apo AI, Apo AII, Apo B and Lp(a), as well as the coagulation parameters; antithrombin III, factor VII, fibrinogen, protein C and protein S, were measured at each occasion. There was a statistically significant drop in total cholesterol and LDL levels. Lp(a) level dropped after commencing treatment and remained below baseline for the rest of the study. The initial increase in Apo AII was not maintained for the duration of the treatment. The changes in Lp(a) and Apo AII were not statistically significant. The level of protein S dropped significantly throughout the study. The changes in other coagulation factors were not statistically significant. The effect of this hormonal combination on the lipid parameters is favourable, and although the change in protein S is striking, its clinical significance remains unclear.