Effect of postmenopausal hormone replacement therapy on lipoprotein and homocysteine levels in Chinese women

Epidemiological studies have revealed that postmenopausal estrogen replacem ent therapy results in a marked reduction in the risk for cardiovascular di seases. In the present study, we evaluated plasma lipoprotein profile as we ll as homocysteine levels in 145 post-menopausal and premenopausal Chinese women living in Hong Kong. We also investigated the effect of hormone-repla cement therapy (HRT) with estrogen or estrogen combined with progestin on p lasma lipoprotein profile and homocysteine concentrations in those individu als. Postmenopausal women displayed significantly higher plasma levels of t otal cholesterol, LDL-cholesterol and apoB as well as higher plasma homocys teine levels than that of premenopausal women. HRT with either estrogen (17 beta -estradiol or conjugated equine estrogen) alone or estrogen combined with progestin for 3.5-4.5 years significantly improved the lipoprotein pro file in postmenopausal women by decreasing the levels of total cholesterol (12-20% reduction), LDL-cholesterol (26-29% reduction) and apoB (21-25% red uction). In women treated with 17 beta -estradiol or conjugated equine estr ogens their plasma levels of apoAI were significantly elevated (18% elevati on) as compared to non-users. HRT also reduced plasma concentrations of hom ocysteine (13-15% reduction). In conclusion, we found that long-term HRT wa s associated with improvement in plasma lipoprotein profile and a reduction in homocysteine concentration in postmenopausal women. These results suppo rt the notion that the improvement of lipoprotein profile and a reduction i n homocysteine concentration may contribute to the beneficial effect of HRT on cardiovascular risk.