Urinary elementomic analysis indicates aluminum as a potential urinary biomarker of sarcopenia in the older adults

Sarcopenia is characterized by aging-related progressive loss of muscle mass and function; however, the specific and sensitive biomarkers are still limited. Biometals and trace elements provide a potential connection linking the environment and lifestyle to pathological processes of sarcopenia. The aim of the present study was to investigate the relationship between urinary trace elements levels and the presence of sarcopenia. A total of 100 older adults aged ≥65 years consisting of 50 patients with sarcopenia and 50 subjects without sarcopenia were enrolled. The urinary concentrations of 35 elements were examined by using inductively coupled plasma mass spectrometry. We found that a panel of 11 urinary elements including Ti, B, Na, Al, K, Ca, V, Rb, Sr, Cs, and Tl were decreased in patients with sarcopenia. Partial correlation analysis showed that urinary levels of Na (r = 0.242, P = 0.017) and Al (r = 0.303, P = 0.002) were positively correlated with gait speed. Multivariate logistic regression analysis showed that urinary Al level (adjusted OR = 0.986, 95 %CI =0.978-0.996, P = 0.004) was negatively associated with the risk of sarcopenia in older adults even after adjustment for potential confounding factors. ROC curve analysis indicated that the optimal cut-off value of urinary Al level for the prediction of sarcopenia was 46.53 μg/mL with a sensitivity of 58 % and a specificity of 78 % (AUC =0.691, 95 % CI =0.587-0.796, P < 0.001). Taken together, our data indicate that urinary Al level shows potential as a biomarker associated with sarcopenia status in older adults. Further studies are needed to confirm the results of our study and elucidate the underlying mechanism by which Al participates in the pathogenesis of sarcopenia.