title: BioCycle study: design of the longitudinal study of the oxidative stress and hormone variation during the menstrual cycle.
abstract: Studies in both human and animal species have suggested that oxidative stress may be associated with health outcomes, including the risk of infertility in both males and females. Sex hormones have been shown to have antioxidant properties. The difficulty in studying the role of oxidative stress in females is partly due to fluctuation in these endogenous sex hormones across the menstrual cycle. The aim of this study was to determine the association of oxidative stress levels with endogenous reproductive hormone levels and antioxidants, including vitamin levels, across the menstrual cycle in a prospective cohort of premenopausal women. The goal was to enroll 250 healthy, regularly menstruating premenopausal women for two menstrual cycles. Participants visited the clinic up to 8 times per cycle, at which time blood and urine were collected. The visits occurred at key hormonally defined phases of the menstrual cycle, with the help of an algorithm based on cycle length and data from a fertility monitor. In addition, participants were administered standardised questionnaires, had various physical measures taken, and had other pertinent data collected. A total of 259 women were enrolled in this study, with 250 completing two cycles, despite a demanding study protocol which participants were required to follow. This report describes the study design, baseline characteristics and visit completion rate for the BioCycle study.
authors.affiliation: Department of Social and Preventive Medicine, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY 14214, USA. jww@buffalo.edu
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
authors.forename: Enrique F
authors.initials: EF
authors.lastname: Schisterman
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Hovey
authors.forename: Penelope P
authors.initials: PP
authors.lastname: Howards
authors.forename: Richard W
authors.initials: RW
authors.lastname: Browne
authors.forename: Mary
authors.initials: M
authors.lastname: Hediger
authors.forename: Aiyi
authors.initials: A
authors.lastname: Liu
authors.forename: Maurizio
authors.initials: M
authors.lastname: Trevisan
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008137:Longitudinal Studies; D008597:Menstrual Cycle / Q000378:metabolism* / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology*; D017697:Premenopause / Q000378:metabolism / Q000502:physiology; D012107:Research Design; D055815:Young Adult
chemical_list: D015415:Biomarkers; D012739:Gonadal Steroid Hormones