TIBOLONE - INFLUENCE ON MARKERS OF CARDIOVASCULAR-DISEASE

Tibolone, a synthetic steroid with estrogenic, androgenic, and progest ogenic properties relieves climacteric symptoms and prevents postmenop ausal bone loss. The influence of tibolone treatment on coagulation, f ibrinolysis, and lipid metabolism was investigated in 91 healthy late postmenopausal women. They were randomly assigned in a double-blind, p lacebo-controlled 2-year study to receive either tibolone 1.25 mg (n = 36, 29 completed) or 2.5 mg (n = 35, 28 completed) or placebo (n = 20 , 13 completed). The biochemical markers of lipid metabolism, fibrinol ysis, and coagulation were measured every 3 months. In both tibolone g roups a similar (similar to 30%) decrease in high density lipoprotein cholesterol and a corresponding lowering of apolipoprotein A-1 (P < 0. 001) was detected. Also serum total cholesterol and triglycerides were reduced (similar to 15%; P < 0.01), whereas low density lipoprotein c holesterol, apolipoprotein B, and lipoprotein(a) were unaffected by ti bolone. The two dose levels of tibolone resulted in a similar, marked lowering (similar to 30%) of tissue plasminogen activator and plasmino gen activator inhibitor activity as compared with placebo (P < 0.001). Plasminogen increased (similar to 15%; P < 0.001) in both groups. Fib rinogen was lowered (P < 0.01) in the low-dose group, and antithrombin III remained unchanged. The overall effect on hemostatic factors of t he present doses of tibolone in healthy, late postmenopausal women ten ds towards increased fibrinolysis and unchanged coagulation. This may be beneficial and might theoretically counterbalance the potentially n egative effect of the decrease in high density lipoprotein cholesterol .