The diagnostic value of serum FGF21 and Irisin in elderly patients with diabetes combined with sarcopenia

Zhang Yi; Wen Yan; Jiang Yuting; Jin Xuelian; Zhang Chenglin; Wu Man

doi:10.3969/j.issn.1671-6450.2025.10.012

Abstract：Objective To analyze the diagnostic value of serum fibroblast growth factor 21(FGF21)and irisin in sarcopenia among elderly patients with diabetes.Methods From December 2021 to December 2024,106 elderly patients with type 2 diabetes mellitus and sarcopenia admitted to the Department of Geriatrics of Suqian Hospital,Jiangsu Provincial People's Hospital were selected as the observation group,while 100 elderly patients with type 2 diabetes mellitus without sarcopenia during the same period served as the control group.Serum FGF21 and irisin levels were measured by ELISA,and muscle markers were assessed using a TMG-S1 muscle status test analyzer.Pearson correlation analysis was used to examine the rela-tionship between serum FGF21 and irisin levels in elderly diabetic patients with sarcopenia.Logistic regression analysis was performed to identify factors associated with sarcopenia,and ROC analysis was used to evaluate the diagnostic value of serum FGF21 and irisin levels.Results Relative appendicular skeletal muscle mass(RASM),grip strength,gait speed,anterior ulnar muscle thickness,ulnar anterior muscle mass,lateral bone muscle thickness,and lateral bone muscle mass in the observation group were significantly lower than those in the control group(t/P=9.713/＜0.001,9.648/＜0.001,17.948/＜0.001,3.400/0.001,3.530/0.001,4.470/＜0.001,6.944/＜0.001).Serum FGF21 levels in the observation group were higher than those in the control group,while serum irisin levels were lower(t/P=7.363/＜0.001,7.651/＜0.001).A negative correlation was observed between serum FGF21 and irisin levels in elderly diabetic patients with sarcopenia(r=-0.420,P＜0.001).High FGF21 levels were identified as an independent risk factor for sarcopenia[OR(95％CI)=3.142(1.404-7.032)],while high irisin levels,RASM,grip strength,gait speed,anterior ulnar muscle thickness,ulnar anterior muscle mass,lateral bone muscle thickness,and lateral bone muscle mass were independent protective factors[OR(95％CI)=0.714(0.583-0.874),0.685(0.548-0.857),0.691(0.558-0.856),0.635(0.478-0.844),0.714(0.565-0.902),0.722(0.554-0.941),0.675(0.511-0.892),0.702(0.532-0.925)].The AUC values of serum FGF21,irisin,and their combination for diagnosing sarcopenia in elderly diabetic patients were 0.783,0.816,and 0.888,respectively.The combined diagnostic value was significantly higher than that of either biomarker alone(Z=2.655,2.164;P=0.008,0.030).Conclusion Serum FGF21 levels are elevated,while irisin levels are reduced,in elderly pa-tients with type 2 diabetes and sarcopenia compared to those with diabetes alone.Serum FGF21 and irisin may serve as useful biomarkers for auxiliary diagnosis of sarcopenia in elderly diabetic patients.