Hormone replacement therapy and cardiovascular disease.

Area of Science:

• Cardiovascular Medicine
• Endocrinology
• Pharmacology

Background:

• Ongoing research investigates hormone replacement therapy (HRT) mechanisms and effects.
• Large clinical trials have recently published significant findings on HRT.
• HRT influences lipid profiles, including LDL-cholesterol, HDL-cholesterol, and triglycerides.

Purpose of the Study:

• To review recent findings on HRT's effects on cardiovascular risk factors and outcomes.
• To evaluate the efficacy of HRT in preventing coronary heart disease (CHD).
• To assess the procoagulant effects of HRT.

Main Methods:

• Analysis of recent studies on HRT's impact on lipoproteins and lipids.
• Review of a landmark randomized placebo-controlled trial (Heart and Estrogen/Progestin Replacement Study) for secondary CHD prevention.
• Comparison of estrogen with simvastatin for lipid-lowering and endothelial function effects.

Main Results:

• Estrogen, with or without progestin, lowers lipoprotein (a) in women.
• Estrogen affects lipids and plasminogen activator inhibitor-1 similarly in men and women.
• Simvastatin is more effective at lowering LDL-cholesterol; estrogen raises HDL-cholesterol.
• HRT did not reduce CHD in a major trial and increased venous thromboembolism.
• Estrogen and simvastatin showed similar benefits for endothelial function, potentially blocked by medroxyprogesterone.

Conclusions:

• HRT's role in CHD prevention remains uncertain due to conflicting results.
• HRT demonstrates procoagulant effects, increasing the risk of venous thromboembolism.
• Selective estrogen receptor modulators are under investigation for CHD prevention, with ongoing trials.