[Hormone replacement Up-to-date. Effects of estrogen replacement therapy on lipid metabolism]

Postmenopausal hormone replacement therapy (HRT) has favorable effects on lipids and decreases the risk of cardiovascular disease (CVD). Since Women's Health Initiative (WHI) has demonstrated that HRT increases the risk of CVD, indications of HRT use have been limited. Oral estrogen has several adverse effects on the risk of CVD. Oral estrogen increases the plasma triglyceride concentrations that decrease the size of LDL particles. Synthetic progestagens such as medroxyprogesterone acetate (MPA) decreases the plasma concentrations of high-density lipoprotein cholesterol. In contrast, recent studies demonstrated that transdermal estrogen or low dose oral estrogen administration, and the use of natural progestagen can protect against adverse effects of oral estrogen. Further studies are needed to investigate whether transdermal or low dose of estrogen administration and the use of natural progestagens can decrease the risk of CVD.