Sex-specific differences in serum neurotrophic and neuromuscular biomarkers in older adults with Sarcopenia

Abstract

Background: Sarcopenia is a multifactorial geriatric syndrome characterized by age-related loss of muscle mass, muscle strength, and physical performance. In recent years, neurotrophic and neuromuscular biomarkers have been investigated as potential diagnostic indicators of sarcopenia; however, evidence regarding their sex-specific differences remains limited. Aim: To evaluate the sex-specific associations of serum BDNF, GDNF, and CAF22 levels with sarcopenia and muscle-related parameters among older adults. Materials and Methods: This analytical cross-sectional study included adults aged 60 years and older. Sarcopenia was defined according to the Asian Working Group for Sarcopenia (AWGS 2019) criteria. Serum BDNF, GDNF, and CAF22 levels were measured using ELISA. Group differences were analyzed using independent t-tests, correlations were assessed using Pearson correlation analysis, and diagnostic performance for sarcopenia was evaluated using receiver operating characteristic (ROC) analysis. Multivariable logistic regression analysis was also performed. Results: No statistically significant differences were observed in serum BDNF, GDNF, and CAF22 levels between sarcopenic and non-sarcopenic participants in either the male or female groups (all p>0.05). ROC analysis demonstrated AUC values ranging from 0.540 to 0.542 in males and from 0.508 to 0.530 in females for BDNF, GDNF, and CAF22. Multivariable logistic regression analysis revealed that age (OR=1.12, 95% CI: 1.04–1.21, p=0.003) and lower fat-free mass index (OR=0.78, 95% CI: 0.66–0.91, p=0.001) were significantly associated with sarcopenia, whereas BDNF, GDNF, and CAF22 showed no independent association with sarcopenia. Conclusions: 1. No statistically significant sex-specific differences were observed in serum BDNF, GDNF, and CAF22 levels between sarcopenic and non-sarcopenic older adults (all p>0.05). 2. CAF22 levels were weakly negatively correlated with muscle mass and fat-free mass index in males (p<0.05), whereas BDNF levels showed weak positive correlations with handgrip strength and fat-free mass index in females (p<0.05). CAF22 levels also demonstrated a weak positive correlation with age (p<0.05). 3. ROC and multivariable logistic regression analyses indicated limited diagnostic utility of BDNF, GDNF, and CAF22 for sarcopenia (AUC=0.508–0.542), and none of these biomarkers showed an independent association with sarcopenia (all p>0.05). In contrast, older age (OR=1.12, p=0.003) and lower fat-free mass index (OR=0.78, p=0.001) were significantly associated with sarcopenia.