Long-term effects of tibolone on circulating levels of vascular cell adhesion molecules and E-selectin in postmenopausal women.

OBJECTIVE

Adherence of lymphocytes and monocytes to cell adhesion molecules (vascular cell adhesion molecules [VCAMs]) expressed by activated endothelial cells is the first step in the development of atherosclerotic disease. It is known that administration of tibolone for 8 weeks reduces serum levels of VCAMs in postmenopausal women. We evaluated the effects of the administration of tibolone in postmenopausal women for 1 year.

DESIGN

Randomized, placebo-controlled, crossover trial.

SETTING

Healthy volunteers in an academic environment.

PATIENT(S): Thirty-six healthy women in postmenopause since 1-4 years.

INTERVENTION(S): Group A received 2.5 mg/d of tibolone and group B received placebo for 12 months; treatment was subsequently crossed over for 1 month.

MAIN OUTCOME MEASURE(S): Serum concentrations of VCAM-1, intercellular adhesion molecule-1 (ICAM-1), and E-selectin were evaluated at baseline and at 6, 12, and 13 months.

RESULT(S): Baseline concentration of VCAM-1, ICAM-1, and E-selectin were similar in both groups. At months 6 and 12, mean concentrations of VCAM-1, ICAM-1, and E-selectin decreased significantly in group A but not in group B. At month 13, levels returned to baseline in group A, whereas they decreased significantly in group B.

CONCLUSION(S): Tibolone causes a rapid and sustained decrease in circulating levels of VCAMs; the effect is lost soon after stopping the treatment. Tibolone induces favorable changes in endothelial function and may exert a direct cardiovascular protective effect in postmenopausal women.