Emma O'DonnellEmma O'Donnell is a PhD candidate in the Department of Exercise Sciences at the University of Toronto. Under the supervision of Dr. Jack Goodman and Dr. Paula Harvey, Emma's thesis work is looking at estrogenic mechanisms of cardiovascular regulation in estrogen deficient premenopausal women.
Discordance between the known biology of estrogen and the results of clinical trials of postmenopausal hormone therapy underscore the need to better characterize, in controlled mechanistic studies, estrogens multiple actions in human health and disease. Exercise-associated amenorrhea (EAA) is a common and reversible cause of estrogen deficiency in premenopausal women thought to be due to energy deficiency. Importantly, premenopausal women with EAA have estrogen deficiency similar to postmenopausal women and thus provide a unique model for examining the cardiovascular effects of estrogen independent of the effects of aging and the presence of other co-morbidities.
Emma's previous work has shown that the women with EAA have disordered regional blood flow, blood pressure and heart rate when compared to exercising normally menstruating women. Her research will go on to examine: 1) the effects of estrogen on vascular function and oxidative stress, as well as neurohumoral mechanisms of vascular function and blood pressure regulation; and 2) to compare these responses in women with EAA in an estrogen deplete and replete environment. This will be achieved by testing women with EAA both before and after 4 weeks of transdermal estrogen therapy.
Emma's work will also investigate whether estrogen deficiency due to EAA obviates the widely recognized cardiovascular benefits of habitual aerobic exercise and premenopausal status, and whether this might contribute to premature development of a cardiovascular phenotype more typically seen in postmenopausal women.