%0 Journal Article
%T Day to Day Variability and Reliability of Blood Oxidative Stress Markers within a Four-Week Period in Healthy Young Men
%A A. H. Goldfarb
%A R. S. Garten
%A J. Waller
%A J. D. Labban
%J Journal of Biomarkers
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/248313
%X 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 ¡À 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 ¦Á 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 ¦Á being 0.913, 0.904, and 0.903, respectively. Xanthine oxidase ICC was 0.163 and Cronbach¡¯s ¦Á 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. 1. Introduction Numerous studies have been published in the last several decades supporting the concept that certain diseases [1, 2], aging [3], and exercise of sufficient intensity and duration [4, 5] can result in oxidative stress. Oxidative stress is a situation in which there is an accumulation of reactive oxygen/nitrogen species beyond the system¡¯s ability to handle or remove them. Oxidative stress has been suggested to occur by measuring several outcome markers that are observed to increase following an intervention or treatment. Typically these markers are from blood [6¨C8], saliva [6], plasma [9], urine [10], or within specific tissues [11, 12] and the results are compared to baseline values but unfortunately these results are reported without concern for diurnal variations or day to day fluctuations. These studies have often utilized both human and animal models to suggest that the intervention has resulted in an accumulation of oxidative stress indices. Many of these studies have utilized a rested control group and compared these results after an intervention (exercise or drug treatment) to the control group. Typically these studies factor in the time of the intervention to prevent diurnal effects. The former approach often factors in diurnal influences to
%U http://www.hindawi.com/journals/jbm/2014/248313/