Summary:
The simultaneous and comprehensive determination of metabolite levels in whole
organisms and their changes over time as a consequence of stimuli such as diet,
lifestyle, environment, genetic effects and pharmaceutical interventions are
all included in the term of metabonomics. For mammalian systems, like humans,
this involves the analysis of biofluids and tissues, and the complex datasets
are usually interpreted using chemometric techniques. In the present study NMR
techniques were applied in 250 urine samples taken from professional
weightlifting handicapped athletes. 57 metabolites were successfully assigned
with the use of 2D NMR spectroscopy and the appropriate internet and
bibliographic data bases. The whole set of spectra was processed with the
appropriate tools, such as MATLAB, in order to perform statistical analysis. In
the resulting dataset unsupervised methods (PCA) and supervised (PLS-DA) were
applied and this led to the creation of the metabolic profiles of each athlete
based on gender, supplement / drug uptake, smoking, exercise seniority,
training for participation in Paraolympic Games and tea uptake in order to draw
conclusions according to their differentiation. Moreover, the metabolic
profiles of each athlete were compared individually and in relation to their
total number in order to find the factors that differentiate them. Also, charts
of the progress of metabolites in relation to the time of sampling were created
for each athlete to gain supplementary information. Many metabolites that are
normally present in urine were observed to be responsible for the above
classifications but due to large heterogeneity of the athletes sample and the
influence of many parameters, the contribution of each metabolite in the
classifications is multifactorial. In non targeted studies with humans there is
variability that causes problems and it can be minimized with the stabilization
of certain factors from the beginning of the study such as standardized diet,
avoiding any vigorous activity and excluding smokers. Ultimately, the use of
NMR spectroscopy, proved ideal for the collection of information related to the
metabotype of a biological system/organism, and this may help in the
diagnosis/treatment of pathological states and can be used as a supplementary
tool to other methods.
Keywords:
Metabonomics, NMR, Nutrition, Athletics, Principal component analysis
