Plasma Extracellular Vesicles-Derived Complement Proteins as Biomarkers of Sarcopenia Progression in Longitudinal Cohorts.

In the KFACS cohort (mean age, 77.7 ± 4.1 years; range, 70.0-84.7; 50.0% women), extracellular vesicles-associated complement proteins, particularly C2 and C4B, were strongly associated with declines in gait speed (β = -0.302, p = 0.006; β = -0.231, p = 0.028, respectively) and were elevated in individuals with worsened outcomes over 2 years (p = 0.002 and p = 0.034, respectively).

Complement pathway enrichment analysis further supported associations with inflammatory and aging-related signatures.