Table of Contents
Journal of Biomarkers
Volume 2014, Article ID 248313, 7 pages
Research Article

Day to Day Variability and Reliability of Blood Oxidative Stress Markers within a Four-Week Period in Healthy Young Men

1Department of Kinesiology, University of North Carolina Greensboro, Greensboro, NC 27402-6170, USA
2Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT 84148, USA
3Office of Research, Health and Human Sciences, University of North Carolina Greensboro, Greensboro, NC 27402-6170, USA

Received 30 July 2014; Accepted 3 October 2014; Published 15 October 2014

Academic Editor: Eugene H. J. M. Jansen

Copyright © 2014 A. H. Goldfarb et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The present study aimed to determine the day to day variability and reliability of several blood oxidative stress markers at rest in a healthy young cohort over a four-week period. Twelve apparently healthy resistance trained males (24.6 ± 3.0 yrs) were tested over 7 visits within 4 weeks with at least 72 hrs between visits at the same time of day. Subjects rested 30 minutes prior to blood being obtained by vacutainer. Results. The highest IntraClass correlations (ICC’s) were obtained for protein carbonyls (PC) and oxygen radical absorbance capacity (ORAC) (PC = 0.785 and ORAC = 0.780). Cronbach’s α reliability score for PC was 0.967 and for ORAC was 0.961. The ICC’s for GSH, GSSG, and the GSSG/TGH ratio ICC were 0.600, 0.573, and 0.570, respectively, with Cronbach’s α being 0.913, 0.904, and 0.903, respectively. Xanthine oxidase ICC was 0.163 and Cronbach’s α was 0.538. Conclusions. PC and ORAC demonstrated good to excellent reliability while glutathione factors had poor to excellent reliability. Xanthine oxidase showed poor reliability and high variability. These results suggest that the PC and ORAC markers were the most stable and reliable oxidative stress markers in blood and that daily changes across visits should be considered when interpreting resting blood oxidative stress markers.