Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Rodler, C.
Gender Differences in Cardiovascular Regulation and Orthostatic Tolerance: a Literature Review
Humanmedizin; [ Diplomarbeit ] Medical University of Graz; 2014. pp. 81
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Goswami Nandu
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- Abstract:
- Background: There is strong evidence for existing gender differences in cardiovascular regulation and orthostatic tolerance. Especially women are prone to orthostatic intolerance. The mechanisms underlying these differences are, however, not fully understood. Purpose: This Diplomarbeit provides an update on current knowledge on gender differences in cardiovascular regulation and orthostatic tolerance. It identifies gaps and alludes to important aspects for future studies on the discussed area. Methodology: A systematic literature research identified relevant articles on gender differences in cardiovascular regulation and orthostatic tolerance. Essential keywords and specific exclusion and inclusion criteria led to a final collection of 158 articles and 1 thesis, all of them being published between 1991 and 2014. The findings were grouped into four key themes: 1) Baseline gender differences affecting cardiovascular function, 2) Gender differences in cardiovascular responses, 3) Influences of sex hormones on cardiovascular regulation and 4) Differences between ethnic groups. These four key themes comprise all identified topics, containing comparisons and summaries of study results as well as suggestions for future work on gender aspects in cardiovascular regulation and orthostatic tolerance. Discussion: Orthostatic tolerance depends on the ability to maintain blood pressure upon orthostatic stress. Premenopausal women are more susceptible to orthostatic intolerance than age-matched men. Differences in anatomy, hemodynamics and the autonomic nervous system seem to form the basis for these gender differences. Moreover, women show differences between themselves. Ovarian hormones appear to cause not only the differences between genders but also the differences between women. Estradiol promotes vasodilation and thereby attenuates vasoconstriction. Women with low orthostatic tolerance are characterized by a greater sensitivity to estradiol and a poor increase in peripheral vascular resistance. Women with high orthostatic tolerance in turn show a greater responsiveness to progesterone and a greater increase in peripheral vascular resistance. While progesterone seems to trigger the activation of the RAAS, its role in cardiovascular regulation remains poorly understood. Recently it has been shown that orthostatic tolerance is higher in black than in white premenopausal women, whereas the underlying mechanisms remain to be identified. In summary, gender differences in orthostatic tolerance seem to be multifactorial, but the influence of female sex hormones on the autonomic nervous system appears to play a major role. Men predominantly respond to orthostatic stress by increasing peripheral resistance, whereas women tend to increase heart rate. Among women it is especially white, young women with a greater sensitivity to estradiol who are prone to orthostatic intolerance.