Controversies regarding hormone therapy: Insights from inflammation and hemostasis

Many observational studies and experimental and animal studies have demonstrated that estrogen therapy (ET) or hormone therapy (HT) significantly reduces the risk of coronary heart disease. Nonetheless, recent randomized controlled trials and the Nurses' Health Study in secondary prevention demonstrate trends toward an increased risk of cardiovascular events rather than a reduction of risk from HT. HT has both anti-inflammatory and pro-inflammatory effects, and it activates coagulation and improves fibrinolysis. These effects depend on the route of administration, doses of estrogen, age of women, and the presence of coronary artery disease or the coexistence of other risk factors for hypercoagulability. In this review, we discuss effects of HT on markers of inflammation, hemostasis, and fibrinolysis that may link endothelial dysfunction in cardiovascular diseases. We also briefly discuss effects of lower doses of HT and tibolone in postmenopausal women.