title: Analytical and biological variation of biomarkers of oxidative stress during the menstrual cycle.
abstract: Little information is available on the intra-individual variability of oxidative stress biomarkers in healthy individuals and even less in the context of the menstrual cycle. The objective of this study was to characterize the analytical and biological variability of a panel of 21 markers of oxidative damage, antioxidant defence and micronutrients in nine healthy, regularly menstruating women aged 18-44 years. Analyses included measurement of lipid peroxidation, antioxidant enzymes and antioxidant vitamins. Blood specimens were collected, processed and stored using standardized procedures on days 2, 7, 12, 13, 14, 18, 22 and 28 in one cycle for each subject. Replicate analyses of markers were performed and two-way nested random effects ANOVA was used to describe analytical, intra-individual and inter-individual variability. No statistically significant differences at alpha=0.05, or temporal effects across the menstrual cycle were observed. Analytical variability was the smallest component of variance for all variables. The ICC among replicates ranged from 0.80 to 0.98. Imprecision based on quality control materials ranged from 1 to 11%. The critical differences between serial results varied greatly between assays ranging from 6 to 216% of the mean level. These results provide important initial information on the variability of biomarkers of oxidative stress, antioxidant defence and micronutrients across the menstrual cycle.
authors.affiliation: Department of Biotechnical and Clinical Laboratory Sciences, University at Buffalo, State University of New York, NY 14214, USA. rwbrowne@buffalo.edu
authors.forename: Richard W
authors.initials: RW
authors.lastname: Browne
authors.forename: Michael S
authors.initials: MS
authors.lastname: Bloom
authors.forename: Enrique F
authors.initials: EF
authors.lastname: Schisterman
authors.forename: Kathy
authors.initials: K
authors.lastname: Hovey
authors.forename: Maurizio
authors.initials: M
authors.lastname: Trevisan
authors.forename: Chengqing
authors.initials: C
authors.lastname: Wu
authors.forename: Aiyi
authors.initials: A
authors.lastname: Liu
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
mesh_terms: D000293:Adolescent; D000328:Adult; D001205:Ascorbic Acid / Q000097:blood; D015415:Biomarkers; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D015227:Lipid Peroxidation; D008597:Menstrual Cycle / Q000378:metabolism*; D018384:Oxidative Stress; D011786:Quality Control; D013482:Superoxide Dismutase / Q000097:blood
chemical_list: D015415:Biomarkers; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001205:Ascorbic Acid