NEFL and sarcopenia: NfL was significantly linked to sarcopenia development (HR 1.20 [1.10; 1.30], p < 0.001), with similar findings for females (HR 1.40 [1.20; 1.63], p < 0.001) and older individuals (HR 1.35 [1.15; 1.58], p < 0.001).