Metabolic Profiles Under Hypoxic Stress: Adolescent Athletes' Experience

Hypoxic training is a method by athletes to enhance their performance at sea level or improve their cardiovascular endurance in moderate-altitude competitions. Comparative studies involving populations from low and moderate altitudes offer an opportunity to understand the mechanisms behind adaptation to hypoxia. Data from GC-MS and LC-MS were combined to compare metabolic profiles of plasma between moderate- and low-altitude adolescent athletes. A total of 161 differential metabolites were identified, including 84 up-regulated and 77 down-regulated metabolites in moderate-altitude adolescents compared to their low-altitude counterparts. Pathway analysis revealed that the significantly different metabolites were associated with carbohydrate, amino acid and lipid metabolism. Lipid metabolism pathways such as linolenic and linoleic acid metabolism, sphingolipid metabolism and arachidonic acid metabolism, as well as processes involving the transfer of acetyl groups into mitochondria and fatty acid biosynthesis, were significantly altered in the moderate-altitude athletes. Receiver operating characteristic analysis detected glycerol and oxo-proline metabolites with a good range of sensitivity and specificity. These metabolites were chosen as biomarker of chronic adaptation to moderate altitude. This study demonstrates differences in metabolic profiles between moderate- and low-altitude populations and highlights the potential of these differential metabolites and metabolic pathways to provide new insights into the mechanisms of adaptation to moderate-altitude