Markers of effect in doping analysis: identification of novel potential biomarkers of doping in blood samples

The knowledge and analysis of the main aspects of the crosstalk between skeletal muscle, adipose tissue, and central nervous system, plays a key role in the study of biochemistry and physiology of physical activity. This preliminary study aims to identify novel potential biomarkers related to energy metabolism, to evaluate their possible diagnostic value if considered for anti-doping purposes, and to identify critical factors in exercise prescription to develop improved training programs. The experimental investigation was carried out on one hundred blood samples from male elite athletes, selected among those collected on the occasion of official anti-doping tests. The analytical approach included both untargeted and targeted methods, to build up the basis of our experimental design. An extensive study about the many physiological pathways allowed us to pre-select a range of potential biomarkers, which are likely to play a key role in the main signaling pathways linked with mitochondrial biogenesis and glucose metabolism, lipolysis, anabolism, thermogenesis, and tissue inflammation. These elected cytokines were pre-selected for the targeted analysis, to evaluate their potential result versus different sport’s category or “in competition” phase or regular training phase. At the same time, we also focused our attention on the cellular energy metabolism networks, investigated by untargeted methods. The results that have been achieved from these different analytical studies were evaluated and integrated into a wider metabolic network in order to better understand the interactions of different pathways, which play a significant role in athletic activity and energy management. If our preliminary results, in terms of the panel of cytokines pre-selected in this study, will be confirmed on a broader population of athletes, and if proved to be sufficiently stable over time, they could be of utility to support the identification of an enough selective panel of biomarkers to be monitored longitudinally, also to verify whether the recourse to doping substances and methods can be detected by monitoring any significant variation from the normality values. Finally, the physiological evidence achieved could be useful also to monitor the well-being of the athlete.