Saito, K, et al., Differences in Metabolite Profiles between Blood Matrices, Ages, and Sexes among Caucasian Indivduals and Their Inter-Individual Variations. Metabolomics, 2013.
Endobiotic metabolites are associated withbiological processes in the body and therefore may serve asbiomarkers for disease states or therapeutic efficacy andtoxicity. However, information is limited regarding howdifferences between blood matrices, patient backgrounds,and sample handling affect human metabolite profiles. Ourobjective was to obtain metabolite profiles from Caucasianindividuals, based on different matrices (plasma andserum), subject backgrounds (male/female and young/old),and storage conditions (2 or 10 freeze–thaw cycles). Intotal, 297 metabolites were detected by LC/MS and GC/MS, and more than 75 % of them were highly representedin all sample groups. The multivariate discriminant analysis(OPLS-DA as a model) singled out the matrix type asthe most important variable influencing global metabolicprofiles; that is, more than 100 metabolites were significantlydifferent based on the matrix type. The influence ofsubject backgrounds on global metabolic profiles wasconsistent between plasma and serum. Age-associateddifferences were more predominant in females than males,whereas gender-associated differences were more prevalentin young subjects than old individuals were. The relativestandard deviation of metabolite levels in subjects with thesame background ranked from 0.1 to 1.5. Moreover, thechanges of metabolite levels caused by freeze–thaw cycleswere limited, and the effect was more prominent in plasmathan serum. These data demonstrate the impact of matrix,age, gender, and freeze–thaw cycles on the metaboliteprofiles and reveal metabolites affected by these factors.Thus, our results provide would useful fundamental informationfor exploring and qualifying biomarkers for clinicalapplications.
Metabolomics Endobiotic metabolite Plasma and serum Age Gender Freeze–thaw cycle