Metabolite biomarkers present in serum and urine predict alterations in skeletal muscle associated with sarcopenia.

Sarcopenia, the progressive loss of muscle mass and strength with age, is associated with many adverse health outcomes in aging populations decreasing greatly health span. Early detection of sarcopenia is critical for initiating preventative strategies to stop muscle deterioration. Current methods for detecting the onset of sarcopenia are inaccessible and costly, creating a barrier to routine screening. Here, we examine serum samples from a group of 360 community-dwelling individuals aged 50 to 70 who previously completed the international physical activity questionnaire (IPAQ). We further analyze urine samples from a group of 60 individuals, who completed standard physical performance battery (SPPB) tests, dual-energy x-ray absorptiometry (DEXA), IPAQ, and an additional questionnaire. We demonstrated for the first time that a panel of biomarkers composed by glutamate, xanthine, taurine, succinate, and carnitine are linked to early alterations in muscle metabolism and can be used to monitor muscle degeneration. These metabolites are detectable in urine and are predictive of sarcopenia as compared to DEXA and physical assessments. This panel serves as a sensitive and objective monitoring tool for assessing muscle metabolism, enabling more effective and accessible management of muscle-wasting conditions such as sarcopenia.