Effects of low-dose 17-β-estradiol plus norethisterone acetate and tibolone on fasting plasma homocysteine levels in postmenopausal women

Background. Many postmenopausal women currently receive hormone replacement therapy. The use of low-dose 17beta-estradiol plus norethisterone acetate and tibolone for hormone replacement therapy is not uncommon in postmenopausal women. Homocysteine, which is known to be an independent risk factor for the development of cardiovascular disease, is found in increased levels postmenopause. This study compared the effects of low-dose 17beta-estradiol plus norethisterone acetate and tibolone on the fasting plasma homocysteine level in healthy postmenopausal women. Methods. Healthy postmenopausal women (n=44) were enrolled in the study. Women randomly assigned received 1 mg of 17beta-estradiol plus 0.5 mg of norethisterone acetate or 2.5 mg tibolone during a period of 12 weeks. Fasting plasma homocysteine levels were measured at baseline, the 4th week, and the 12th week of therapy. Results. In the 4th week there were no significant changes in plasma homocysteine levels in both groups (p>0.05). However at the end of the 12th week the plasma homocysteine levels were reduced significantly in both groups (p<0.05). Conclusion. Low-dose 17beta-estradiol plus norethisterone acetate and tibolone lower the fasting plasma homocysteine levels in healthy postmenopausal women.