Growth Differentiation Factor 15 and Physical Function Impairment in the SardiNIA Study

Background: Sarcopenia is the age-related, progressive loss of strength, function, and skeletal muscle mass, which can be assessed with specific tests. The Growth differentiation factor 15 (GDF-15) has been proposed as a key biomarker of aging, and it has been associated with mitochondrial dysfunction, cachexia, and physical impairment. Methods: The cohort of this study comes from the SardiNIA study, an ongoing longitudinal survey focused on the identification of genetic and phenotypic variants associated with aging. We assessed hand grip strength, gait speed, and GDF-15 in all samples. Linear multivariate analysis was used to assess the correlation after adjusting for a range of potential confounders. Results: The sample consisted of 4842 subjects (57.5% female) with a median age of 48.6 years. Levels of GDF-15 were comparable between males and females and showed a strong positive association with aging (rho 0.617, p < 0.001). Linear multivariate regression analyses showed that GDF-15 was negatively associated with gait speed and grip strength in both hands (respectively, Beta -0.09, Beta -0.07, and Beta -0.08, p < 0.001 for all). Conclusions: GDF-15 was negatively associated with physical function. GDF-15 may be considered a proxy for reduced physical performance. Future research is needed to understand the pathogenetic role of GDF-15 in the reduction in skeletal muscle in aging people.