Influence of Endogenous Reproductive Hormones on F2-Isoprostane Levels in Premenopausal Women: The BioCycle Study

摘要

Endogenous reproductive hormones and oxidative stress have been independently linked to risk of chronicndisease but mostly in postmenopausal women. The interplay between endogenous reproductive hormones andnoxidative stress among premenopausal women, however, has yet to be clearly elucidated. The objective of thisnstudy was to investigate the association between endogenous reproductive hormones and F2-isoprostanes in thenBioCycle Study. Women aged 18–44 years from western New York State were followed prospectively for up ton2 menstrual cycles (n ¼ 259) during 2005–2007. Estradiol, progesterone, luteinizing hormone, follicle-stimulatingnhormone, sex hormone-binding globulin, F2-isoprostanes, and thiobarbituric acid-reactive substances were measurednup to 8 times per cycle at clinic visits timed by using fertility monitors. F2-Isoprostane levels had an independentnpositive association with estradiol (b ¼ 0.02, 95% confidence interval: 0.01, 0.03) and inversenassociations with sex hormone-binding globulin and follicle-stimulating hormone (b ¼ u00010.04, 95% confidenceninterval: u00010.07, u00010.003; b ¼ u00010.02, 95% confidence interval: u00010.03, u00010.002, respectively) after adjustmentnfor age, race, age at menarche, c-tocopherol, beta-carotene, total cholesterol, and homocysteine by inversenprobability weighting. Thiobarbituric acid-reactive substances, a less specific marker of oxidative stress, hadnsimilar associations. If F2-isoprostanes are specific markers of oxidative stress, these results call into questionnthe commonly held hypothesis that endogenous estradiol reduces oxidative stress.