NEFL and sarcopenia: When the diagnostic accuracy of NF-L was assessed as a biomarker of sarcopenia, the area under the curve (AUC) obtained through ROC analyses was 0.784 for all sarcopenic subjects (p-value < 0.001) with a sensitivity of 68.7% and a specificity of 81.4% for an optimal cut-off point at 31.6 pg/mL (Fig. 3b).