Effects of hormone replacement therapy on cardiovascular risk factors in postmenopausal women

Objective: To investigate changes in plasma lipoprotein profile, hemostatic factors, platelet aggregation, endothelin-1, and cardiac function during postmenopausal sequential 6-month hormone replacement therapy (HRT). Design: Open longitudinal prospective study. Setting: Gynecologic department of a medical center. Patient(s): Twenty-one healthy nonhysterectomized postmenopausal women. Intervention(s): Oral E₂ valerate (2 mg/d) combined with medroxyprogesterone acetate (MPA) (10 mg/d) during the last 10 days of each 21-day cycle. The treatment period was 6 months. Main Outcome Measure(s): Plasma lipoprotein profile, hemostatic parameters, platelet aggregation, endothelin-1, and left ventricular function. Result(s): After 6 months of treatment, total cholesterol, triglyceride, and low-density lipoprotein (LDL) cholesterol were significantly progressively reduced. Atherogenic indices of total cholesterol-to-high-density lipoprotein (HDL) cholesterol and LDL-to-HDL cholesterols also showed a significant progressive decline. The concentrations of antithrombin III were significantly increased. The maximum aggregation and slope of platelet aggregation were significantly reduced, but all parameters were more pronounced at 1 month of HRT than at 3 or 6 months. The concentrations of endothelin-1 were significantly reduced (by 16.1%). In the evaluation of left ventricular function, only peak atrial diastolic velocity was significantly reduced. Conclusion(s): Combined HRT had favorable effects on lipids and lipoproteins, hemostatic factors, platelet aggregation, endothelin-1, and left ventricular function. However, further study is needed to evaluate the long-term effects of combined HRT, especially on platelet aggregation and cardiac function.