The effects of transdermal estradiol on the response to mental stress in postmenopausal women: a randomized trial

PURPOSE: Estrogens inhibit adrenomedullary catecholamine release and catecholamine-mediated responses to stress. We examined whether estrogen supplementation reduces the sympathoadrenal response to mental stress in postmenopausal women. MATERIALS AND METHODS: We compared the effects of 3-week treatment with transdermal 17-beta-estradiol and placebo in 10 postmenopausal women using a randomized, blinded, crossover design. We measured plasma catecholamine levels and the cardiovascular and metabolic responses to a 15-minute stress with mental arithmetic. Treatments were compared using repeated measures analysis of variance. RESULTS: During placebo treatment, mean (± SD) epinephrine levels reached a peak of 431 ± 135 pmol/liter after 15 minutes of stress; the epinephrine response was blunted during estradiol treatment, with a peak of 357 ± 77 pmol/liter (P<0.05). Estradiol also blunted the diastolic blood pressure response to stress (baseline levels of 78 ± 15 mm Hg vs peak of 90 ± 6 mm Hg during placebo; baseline of 80 ± 8 mm Hg vs peak of 84 ± 6 mm Hg during estradiol; P<0.05). Estradiol treatment also blunted the decrease in the standard deviation of the mean of the electrocardiographic RR intervals and the increase in the ratio between the low-frequency and high-frequency bandwidths. CONCLUSION: We observed a moderate, although significant, reduction in markers of the stress response to mental arithmetic in postmenopausal women treated with transdermal 17-beta-estradiol.