Short-term effect of transdermal estrogen on autonomic nervous modulation in postmenopausal women.

ABSTRACT

OBJECTIVE: To evaluate the effect of short-term transdermal estradiol-l7b on cardiac autonomic nervous modulation in postmenopausal women. DESIGN: Prospective study. SETTING: A tertiary medical center. PATIENT(S) Twenty-one postmenopausal women. INTERVENTION(S) Transdermal estradiol or placebo therapy for 3 weeks in randomized, double-blinded, crossover fashion. MAIN OUTCOME MEASURE(S) Heart rate variability measures in both time and frequency domains, serum biochemistry, and climacteric symptoms were compared among baseline, placebo and transdermal estrogen therapies. RESULT(S) Plasma concentration of estradiol rose significantly from 11.0 +/- 5.2 pg/ml to 48.2 +/- 34.0 pg/ml after transdermal estrogen. The standard deviation of RR-interval increased significantly from 30.3 +/- 9.9 ms (placebo) to 31.3 +/- 7.4 ms (transdermal estrogen), and the coefficient of variation of RR-interval increased significantly as compared with the baseline session. The total power was marginally increased as compared among baseline, placebo, and transdermal estrogen sessions. The irritability symptom decreased significantly after transdermal estrogen therapy, as compared with baseline and placebo treatment. CONCLUSION(S) Transdermal estradiol for 3 weeks could significantly increase the global heart rate variability and reduce the irritability symptom in the postmenopausal women. Short-term transdermal estrogen for 3 weeks could improve cardiac autonomic nervous modulation and climacteric symptoms, and might have some cardioprotective effect in postmenopausal women.