In the logistic regression model, NF-L was an independent predictor of severe sarcopenia (p = 0.0338; OR = 20.0; 95% CI 1.39–287.7) with satisfactory diagnostic accuracy (AUC: 0.828) and subjects with an SPPB score ≤ 8 had higher odds of having increased NF-L (p < 0.0001; OR = 23.9; 95% CI 5.5–104). This evidence concerns the gene NEFL and sarcopenia.