Abstract: Objective To investigate the diagnostic value of triglyceride-glucose index (TyG) and brain-derived neurotrophic factor (BDNF) for sarcopenia in non-diabetic maintenance hemodialysis (MHD) patients.  Methods  A total of 126 MHD patients admitted to our hospital from January 2021 to January 2023 were recruited as the research subjects. According to the diagnostic criteria revised by the Asian Sarcopenia Working Group (AWGS) in 2019, the incidence of sarcopenia was calculated and analyzed. Serum levels of triglyceride, glucose and BDNF were assayed, and TyG was calculated. Pearson correlation was used to evaluate the correlations between the biomarkers of TyG and BDNF and the sarcopenia indexes of skeletal muscle mass index (SMI), grip strength and walking speed. Multivariate logistic regression was conducted to analyze the influencing factors for sarcopenia in MHD patients. The receiver operating characteristic (ROC) curve was established to assess the values of TyG and BDNF for the diagnosis of sarcopenia in MHD patients.  Results Thirty-nine MHD patients (30.95%) were complicated with sarcopenia. Compared with non-sarcopenia group, TyG was higher (t=7.974, P＜0.001) and BDNF was lower in sarcopenia group (t=14.699, P＜0.001). In sarcopenia group, TyG was negatively correlated with SMI, grip strength and walking speed (r=-0.365, -0.319 and -0.452 respectively; P<0.001), while BDNF was positively correlated with SMI, grip strength and walking speed (r=0.326, 0.275 and 0.395 respectively; P<0.001, =0.003, <0.001 respectively). Older age (OR=1.861, 95% CI：1.040～3.330, P=0.019) and higher TyG (OR=2.050, 95% CI：1.049～4.008, P=0.015) were the risk factors for sarcopenia in MHD patients, while higher albumin (OR=0.694, 95% CI：0.515～0.935, P=0.008) and higher BDNF (OR=0.630, 95% CI：0.430～0.923, P=0.010) were the protective factors for sarcopenia in MHD patients. The areas under the curve using TyG or BDNF for the diagnosis of sarcopenia were 0.740 (95% CI：0.654～0.814, P<0.001) and 0.727 (95% CI：0.641～0.803, P<0.001) respectively; the area under the curve using both TyG and BDNF for the diagnosis of sarcopenia was 0.939 (95% CI：0.882～0.974, P<0.001), higher than those using TyG and BDNF individually for the diagnosis (Z=4.075 and 4.241, P<0.001).  Conclusion  The increase of TyG and the decrease of serum BDNF are associated with sarcopenia in MHD patients. The combination of TyG and BDNF can improve the risk assessment of sarcopenia in MHD patients.

Key words: Triglyceride-glucose index, Brain-derived neurotrophic factor, Maintenance hemodialysis, Sarcopenia