Hormone Replacement and Neural Cardiovascular Control in Postmenopausal Women
Status:
Terminated
Trial end date:
2015-08-01
Target enrollment:
Participant gender:
Summary
Older women have an exaggerated increase in blood pressure during exercise. However, the
reasons for this are unclear. It is important to investigate this phenomenon because a
greater blood pressure response to exercise has been associated with an increased risk of
stroke and mortality in otherwise healthy individuals. A unique aspect of aging in women is
the profound change in hormone levels (i.e. estrogen and progesterone) associated with
menopause. The influence of changes in estrogen and progesterone levels on the cardiovascular
responses to exercise is poorly understood. However, it has been suggested that these
hormones might change the responsiveness of the cardiovascular system. Possible mechanisms
that could account for these changes are the arterial baroreflex and feedback from the
exercising muscle (known as the exercise pressor reflex), both of which are known to
powerfully modulate blood pressure during exercise. However, to date, few human studies have
thoroughly examined the influence of changes in hormone levels on baroreflex function during
exercise or the exercise pressor reflex in older women. As such, the purpose of this research
project is to assess baroreflex function and the exercise pressor reflex in older women after
transdermal estrogen and placebo.