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

Abstract

Endogenous reproductive hormones and oxidative stress have been independently linked to risk of chronic disease but mostly in postmenopausal women. The interplay between endogenous reproductive hormones and oxidative stress among premenopausal women, however, has yet to be clearly elucidated. The objective of this study was to investigate the association between endogenous reproductive hormones and F(2)-isoprostanes in the BioCycle Study. Women aged 18-44 years from western New York State were followed prospectively for up to 2 menstrual cycles (n = 259) during 2005-2007. Estradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, F(2)-isoprostanes, and thiobarbituric acid-reactive substances were measured up to 8 times per cycle at clinic visits timed by using fertility monitors. F(2)-Isoprostane levels had an independent positive association with estradiol (beta = 0.02, 95% confidence interval: 0.01, 0.03) and inverse associations with sex hormone-binding globulin and follicle-stimulating hormone (beta = -0.04, 95% confidence interval: -0.07, -0.003; beta = -0.02, 95% confidence interval: -0.03, -0.002, respectively) after adjustment for age, race, age at menarche, gamma-tocopherol, beta-carotene, total cholesterol, and homocysteine by inverse probability weighting. Thiobarbituric acid-reactive substances, a less specific marker of oxidative stress, had similar associations. If F(2)-isoprostanes are specific markers of oxidative stress, these results call into question the commonly held hypothesis that endogenous estradiol reduces oxidative stress.

Dairy Food Intake Is Associated with Reproductive Hormones and Sporadic Anovulation among Healthy Premenopausal Women

“…Details of the study design and sample collection are described elsewhere (15). In brief, the BioCycle Study was designed to determine the association of oxidative stress levels with endogenous reproductive hormone and antioxidant concentrations across the menstrual cycle in a prospective cohort of premenopausal women (15)(16)(17). The study prospectively recruited 259 healthy, regularly menstruating women with self-reported cycle lengths of 21-35 d for $6 mo before recruitment from western New York in [2005][2006][2007].…”

Oxidative damage and the pathogenesis of menopause related disturbances and diseases

“…A potential interplay between endogenous sexual hormones (including E2, sex hormonebinding globulin, follicle stimulating hormones, etc.) and F2-iso, as reliably measured by GS-MS, was also prospectively investigated in BioCycle Study, a cohort investigation on 259 women aged 18-44 years followed for two menstrual cycles [123]. F2-iso displayed positive independent association with circulating E2 levels throughout the menstrual cycle.…”

Changes in macronutrient, micronutrient, and food group intakes throughout the menstrual cycle in healthy, premenopausal women

“…The BioCycle study was designed to investigate oxidative stress levels across the menstrual cycle in healthy women age 18–44 [13] who were followed for one ( n = 9) or two menstrual cycles ( n = 250). The study design, procedures, and participants have been described in detail elsewhere [14].…”