Effects of bioidentical hormone therapy on endothelial function and blood pressure

Abstract

BACKGROUND: Traditional hormone therapy (HT) is effective for managing menopausal symptoms. Although controversial, HT may also have cardioprotective effects, such as improving endothelial function. However, HT usage plummeted following the Women’s Health Initiative. A popular therapeutic option that has emerged as an alternative is bioidentical hormone therapy (bioHT). Although popular for its claim of being a natural therapy, the effects of bioHT on the cardiovascular system, specifically endothelial function and blood pressure, are not well established in menopausal women. PURPOSE: To test the hypothesis that 5 weeks of bioHT will improve endothelial function and blood pressure in menopausal women. METHODS: Women were recruited from the local community and clinics offering bioHT. Women seeking bioHT completed baseline testing (pre) within seven days of pellet insertion, and again after 5 weeks of treatment (post). Control women were not using any form of hormones, and measured at their convenience 5 weeks apart. Endothelial function was measured using brachial artery flow mediated dilation (FMD). Resting brachial blood pressure was recorded in triplicate in the supine position using an automated sphygmomanometer (Dinamap Dash 2000). Comparisons were made using two-way repeated measures ANOVA. RESULTS: Eleven women completed the study: 4 bioHT (57 ± 5 yrs) and 7 Control (54+4 yrs). Women were well matched for body mass index (bioHT: 25+3 kg/m2; control: 24+3 kg/m2; p=0.75), total cholesterol (bioHT: 213+71mg/dL; control 206+46mg/dL, p=0.84), and fasting plasma glucose (bioHT: 89+6mg/dL; control 90+13mg/dL, p=0.83). After 5 weeks, FMD did not change in bioHT (pre: 4.89% ± .8; post: 5.76% ± 2.2) or control women (pre: 3.73% ± 1.3; post: 4.18% ± 1.7; p>0.10). Resting systolic blood pressure was also not different after 5 weeks in bioHT (pre: 132 ± 20mmHg, post: 126 ± 17mmHg) or control women (pre: 113 ± 5mmHg, post: 110 ± 9mmHg; p>0.05). However, resting diastolic blood pressure tended to decrease in bioHT (pre: 79 ± 12mmHg, post: 72 ± 11mmHg; p=0.08) but not control women (pre: 71 ± 5 mmHg, post: 70 ± 7mmHg; p=0.52). CONCLUSION: These preliminary findings suggest that 5 weeks of bioHT does not negatively impact endothelial function, and may lower resting blood pressure. Additional data are needed to further assess the implications of bioHT on the cardiovascular system. Supported by NIH R01 HL 146558 and P20 GM113125 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.