Effect of low-dose estrogen on hemodynamic response to stress

Objective: To determine the effect of low-dose esterified estrogen on hemodynamic responses at rest and during stress in postmenopausal women, and to compare the changes with those seen with conjugated equine estrogen. Design: Open-label study of esterified estrogen compared with a double-blind, placebo-controlled investigation of conjugated equine estrogen. Setting: Healthy volunteers in an academic research environment. Patient(s): Postmenopausal women with normal endometrium, not currently using hormones. Intervention(s): Cardiovascular parameters at rest and in response to stressors were assessed in 11 postmenopausal women before and 6 months after receiving 0.3 mg esterified estrogen. Responses were compared with 42 postmenopausal women randomized to 0.625 mg conjugated equine estrogen or placebo. Main Outcome Measure(s): Changes in mean arterial pressure (MAP) and vascular resistance index from before to after treatment. Result(s): At rest, MAP increased 3.3 ± 1.5 mm Hg (±SD) in the placebo group, while declining 2.3 ± 1.5 mm Hg and 4.8 ± 1.4 mm Hg, respectively, in the esterified estrogen and conjugated equine estrogen groups after treatment. During mental stressors, MAP dropped significantly in both treatment groups. At rest and during mental stressors, vascular resistance index decreased with estrogen treatment. Conclusion(s): Low-dose esterified estrogen improved hemodynamic patterns similar to standard doses of conjugated equine estrogen in postmenopausal women.