A 2-YEAR STUDY OF LIPID AND LIPOPROTEIN CHANGES IN POSTMENOPAUSAL WOMEN WITH TIBOLONE AND ESTROGEN-PROGESTIN

Objective: To assess changes in lipid-lipoprotein profile in postmenop ausal women taking tibolone and estrogen-progestin, compared with untr eated controls. Methods: Sixty-three women were randomized to take a c ombined estrogen-progestin preparation (n = 31) or tibolone (n = 32), and 50 other women acted as controls. Fasting lipid-lipoprotein levels were measured over 96 weeks. Results: The controls, who were older an d postmenopausal longer than the therapy subjects, exhibited significa nt decreases in total (P < .05) and low-density lipoprotein (LDL) (P < .001) cholesterol and increases in triglyceride (P < .05) and lipopro tein (a) (P < .001) over the 96-week period of study. Lipoprotein (a) also decreased significantly in both treated groups (P < .001). Total and LDL cholesterol decreased and triglyceride increased in the estrog en-progestin group, but, compared with controls, these changes were no t significant. Total cholesterol decreased in the tibolone group, alth ough decreases in low- and particularly high-density lipoprotein (HDL) (P < .001) cholesterol and parallel decreases in apolipoprotein A(1) (P < .001) and B (P < .01) were also observed. There was evidence of a reversion phenomenon in apolipoproteins A(1) and B in all groups, and in lipoprotein (a) with tibolone. Conclusion: Some changes accompanyi ng tibolone may be favorable and may counter its adverse effect on HDL cholesterol. Lowering of lipoprotein (a) was the only significant cha nge found with estrogen-progestin.