title: Short-term oral progesterone administration antagonizes the effect of transdermal estradiol on endothelium-dependent vasodilation in young healthy women.
abstract: Very few studies have explored the cardiovascular effects of progesterone in premenopausal women. This study aimed to examine the short-term effects of oral progesterone alone, transdermal estrogen alone, and progesterone and estrogen combined on flow-mediated dilation (FMD) in healthy reproductive-aged women. We suppressed endogenous estrogens and progesterone in 17 premenopausal women for 10-12 days using a gonadotropin-releasing hormone antagonist. On day 4 (hormone suppression condition), subjects were tested (n = 17) and were then supplemented with either 200 mg micronized progesterone (n = 8) orally or 0.1 mg estradiol (n = 9) transdermally per day. On day 7 (progesterone-first or estradiol-first condition), subjects were tested and began supplementation with both hormones (n = 17) and were tested again on day 10 (combined hormone condition). FMD of the brachial artery was assessed using B-mode arterial ultrasound, combined with synchronized Doppler analysis. As a result, significant differences in FMD were observed between hormone suppression (7.85 ± 1.06%) and estrogen-first conditions (10.14 ± 1.40%; P < 0.05). The estradiol-induced increase was abolished when oral progesterone was also supplemented (6.27 ± 0.96%). In contrast, we observed a trend toward a decrease in FMD with unopposed progesterone administration, but no statistically significant differences were found between the progesterone-first (6.66 ± 1.23%), hormone suppression (7.80 ± 1.23%), and combined hormone conditions (7.40 ± 1.29%). In conclusion, these data suggest that short-term oral micronized progesterone administration antagonizes the beneficial effect of transdermal estradiol on FMD.
authors.affiliation: Department of Human Physiology, University of Oregon, Eugene, OR 97403, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Miner
authors.forename: Emily R
authors.initials: ER
authors.lastname: Martini
authors.forename: Michael M
authors.initials: MM
authors.lastname: Smith
authors.forename: Vienna E
authors.initials: VE
authors.lastname: Brunt
authors.forename: Paul F
authors.initials: PF
authors.lastname: Kaplan
authors.forename: John R
authors.initials: JR
authors.lastname: Halliwill
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Minson
mesh_terms: D000293:Adolescent; D000328:Adult; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D004562:Electrocardiography / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects*; D004958:Estradiol / Q000494:pharmacology*; D004965:Estrogen Antagonists; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D011374:Progesterone / Q000494:pharmacology*; D018608:Ultrasonography, Doppler; D014664:Vasodilation / Q000187:drug effects*; D055815:Young Adult
chemical_list: D004965:Estrogen Antagonists; D011374:Progesterone; D004958:Estradiol