Background: Sarcopenia is a multifactorial pathophysiologic condition of skeletal muscle mass and muscle strength associated with aging. However, biomarkers for predicting the occurrence of sarcopenia are rarely discussed in recent studies. The aim of the study was to elucidate the relationship between sarcopenia and several pertinent biomarkers.
Methods: Using the Gene Expression Omnibus (GEO) profiles of the National Center for Biotechnology Information, the associations between mRNA expression of biomarkers and sarcopenia were explored, including high temperature requirement serine protease A1 (HtrA1), procollagen type III N-terminal peptide (P3NP), apelin, and heat shock proteins 70 (Hsp72). We enrolled 408 community-dwelling adults aged 65 years and older with sarcopenia and nonsarcopenia based on the algorithm proposed by the Asian Working Group for Sarcopenia (AWGS). Muscle strength is identified by hand grip strength using an analogue isometric dynamometer. Muscle mass is estimated by skeletal mass index (SMI) using a bioelectrical impedance analysis. Physical performance is measured by gait speed using 6 m walking distance. The associations between these biomarkers and sarcopenia were determined using receiver operating characteristic (ROC) curve analysis and multivariate regression models.
Results: From the GEO profiles, the sarcopenia gene set variation analysis score was correlated significantly with the mRNA expression of APLNR (p < 0.001) and HSPA2 (p < 0.001). In our study, apelin was significantly associated with decreased hand grip strength with β values of - 0.137 (95%CI: - 0.229, - 0.046) in men. P3NP and HtrA1 were significantly associated with increased SMI with β values of 0.081 (95%CI: 0.010, 0.153) and 0.005 (95%CI: 0.001, 0.009) in men, respectively. Apelin and HtrA1 were inversely associated with the presence of sarcopenia with an OR of 0.543 (95%CI: 0.397-0.743) and 0.003 (95%CI: 0.001-0.890) after full adjustment. The cutoff point of HtrA1 was associated with the presence of sarcopenia with an OR of 0.254 (95%CI: 0.083-0.778) in men. The cutoff point of apelin was negatively associated with the presence of sarcopenia with an OR of 0.254 (95%CI: 0.083-0.778).
Conclusion: Our study highlights that P3NP, HtrA, and apelin are useful for diagnosis of sarcopenia in the clinical setting.
Keywords: Biomarkers; Gender; Inflammation; Muscle loss; Sarcopenia.