Lipid profiles and endothelial function with low-dose hormone replacement therapy in postmenopausal women at risk for coronary artery disease: a randomized trial

Aims: To compare the effect of low (0.3 mg) and commonly prescribed (0.625 mg) doses of conjugated equine estrogens (CEE) on brachial artery flow-mediated dilation and lipid profiles. Methods and results: Twenty-five postmenopausal women (mean age, 65±6 years) at risk for coronary artery disease (CAD) (≥2 established risk factors) entered a double-blind crossover study. Brachial artery endothelial function was evaluated by means of high-resolution vascular echography. Both CEE doses significantly decreased total cholesterol (−13%, 0.3 mg; −15%, 0.625 mg), low-density lipoprotein–cholesterol (LDL-C) (−15%, 0.3 mg; −16%, 0.625 mg), and lipoprotein(a) (−28%, 0.3 mg; −39%, 0.625 mg) values from baseline levels. Both treatments increased high-density lipoprotein–cholesterol (HDL-C) (5%, 0.3 mg; 7%, 0.625 mg) and triglycerides (3%, 0.3 mg; 8%, 0.625 mg). There was no dose effect for changes in the LDL-C/HDL-C ratio (−21%, 0.3 mg; −23%, 0.625 mg). Both doses improved brachial artery dilation during reactive hyperemia by 63% over baseline. Conclusion: In women at risk for CAD, low-dose hormone replacement treatment (HRT) improves lipid profiles and brachial artery endothelial function comparably to the most commonly prescribed dose. The benefit:risk ratio of low-dose HRT provides an attractive option for postmenopausal women at risk for CAD.