Evidence of a role of endogenous estrogen in the modulation of autonomic nervous system

Autonomic modulation of heart rate of young and postmenopausal women undergoing estrogen therapy

“…Previous studies have also shown changes in the autonomic control of HR following natural (12)(13)(14)27) or surgical menopause (15). In agreement with the results of these studies, our results show that menopause can cause an imbalance of the autonomic nervous control of the cardiovascular system that shifts toward sympathetic hyperactivity.…”

“…Therefore, the present findings agree with previous studies (14,15,27), which have reported increased vagal activity and reduced sympathetic drive in postmenopausal women undergoing estrogen therapy. Nevertheless, the mechanism responsible for the beneficial effect of estrogen therapy on autonomic control of HR remains unknown and should be explored in future studies.…”

“…Brockbank et al (13) and Liu et al (14) noted higher HRV values in premenopausal than in postmenopausal women. Mercuro et al (15) observed decreased HRV indices in women submitted to bilateral oophorectomy. However, when these patients were placed on therapy with 17ß-estradiol, all HRV indices returned to their pre-surgery levels.…”

Do muscle strengthening exercises improve performance in the 6-minute walk test in postmenopausal women?

“…In the EG, there was an increase in the final HR after 3 months of exercise. Mercuro et al 5 and Liu, Kuo and Yang 6 found an influence of hypoestrogenism due to menopause in the autonomic nervous system, with a predominance of sympathetic activity. Possibly, the increase in HR in the EG was due to the inclusion of postmenopausal women who were not taking HRT.…”

“…There are also reports that a higher incidence of cardiovascular disease is one of the co-morbidities associated with climacteric hypoestrogenism 4 . Studies have shown negative effects of hypoestrogenism on heart rate (HR) variability [5][6] , which is influenced by sympathetic and parasympathetic activity. The efferent sympathetic system increases HR, whereas the efferent parasympathetic system reduces it 7 .…”