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This Article Full Text Full Text (PDF) All Versions of this Article: 294/4/H1630    most recent 01314.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Meendering, J. R. Articles by Minson, C. T. PubMed PubMed Citation Articles by Meendering, J. R. Articles by Minson, C. T.

Estrogen, medroxyprogesterone acetate, endothelial function, and biomarkers of cardiovascular risk in young women

¹Department of Human Physiology, University of Oregon, Eugene, and ²Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Oregon Health and Sciences University, Portland, Oregon

Submitted 9 November 2007 ; accepted in final form 11 February 2008

Medroxyprogesterone acetate (MPA) is widely known for its use in combination hormone therapy for postmenopausal women. However, MPA is also commonly used in young women for contraception and treatment of a number of gynecological conditions. Despite its widespread use, the cardiovascular effects of MPA in young women are unclear. Therefore, the purpose of this study was to determine the acute effects of MPA when used in combination with estradiol on markers of cardiovascular risk in young women. We suppressed endogenous estrogens and progesterone in 10 premenopausal women using a gonadotropin-releasing hormone antagonist (GnRHa) for 10 days. On day 4 of GnRHa subjects received 0.1 mg of estradiol (GnRHa+E₂), and on day 7 5 mg of MPA was added (GnRHa+E₂+MPA). Endothelium-dependent vasodilation and endothelium-independent vasodilation of the brachial artery, lipids, homocysteine, high-sensitivity C-reactive protein, and endothelin-1 were assessed during treatment with GnRHa, GnRHa+E₂, and GnRHa+E₂+MPA. Four additional subjects were tested to validate the efficacy of the GnRHa model and confirm the findings. Endothelium-dependent vasodilation was greater during GnRHa+E₂ than during GnRHa or GnRHa+E₂+MPA (P = 0.006). Endothelin-1 was lower during GnRHa+E₂ than GnRHa alone (P = 0.039). Endothelin-1 increased with the addition of MPA and was not significantly different from GnRHa alone. There were no differences in the other markers of cardiovascular risk between hormone treatment days. These data suggest that acute MPA administration negates the beneficial effects of estradiol on endothelium-dependent vasodilation in young women. In addition, these data suggest that estradiol decreases endothelin-1 concentrations and the addition of MPA may counteract the effect of estradiol on endothelin-1.

endothelium; hormones; flow-mediated vasodilation; endothelin-1; progestins