Aims: To assess the effect of simvastatin, hormone replacement therapy and their combination on soluble cell adhesion molecules and plasma lipids, in hypercholesterolaemic post-menopausal women with coronary artery disease.
Methods: We studied 16 post-menopausal women with coronary artery disease and hypercholesterolaemia (total cholesterol >200mg x dl(-1) and LDL cholesterol >130 mg x dl(-1)). We compared simvastatin (20 mg daily) with hormone replacement therapy (0.625 mg conjugated oestrogen and 2.5 mg medroxyprogesterone acetate daily) and their combination, in a randomized, crossover, placebo controlled study. Each treatment period was 8 weeks long with a 4 week washout interval between treatments. Circulating cell adhesion molecules and plasma lipids were evaluated at the end of each treatment period.
Results: All three active treatments--simvastatin, hormone replacement therapy and the combination therapy--significantly reduced total and LDL cholesterol, compared to placebo (P<0.001). Only hormone replacement therapy, alone and in combination with simvastatin, significantly decreased lipoprotein(a) when compared to placebo (P<0.05), whereas simvastatin had no significant effect. Likewise, hormone replacement therapy and the combination therapy significantly reduced the intercellular adhesion molecule (ICAM-1) plasma levels (P=0.03 and P=0.02, respectively), while simvastatin, which was superior to hormone replacement therapy in lowering total and LDL cholesterol, did not modify ICAM-1 levels; the combination therapy was not more effective than hormone replacement therapy alone in ICAM-1 reduction. Neither the effect, on any treatment when compared to placebo, of VCAM-1 nor E-selectin levels differed significantly.
Conclusions: Hormone replacement therapy may limit the inflammatory response to injury by modulating the expression of cell adhesion molecules from the endothelial cells, possibly in association with lipoprotein (a) reduction.