Abstract: ABSTRACT ： Objective ： To investigate the relationship between serum Reverse Triiodothyronine（rT3）and sarcopenia in the patients undergoing maintenance hemodialysis （MHD）Methods：The clinical data of MHD were collected. Pre-dialysis serum biochemical parameters and thyroid function indicators were systematically obtained and recorded. Body composition was assessed via bioelectrical impedance spectroscopy. Functional metrics included grip strength, 6-meter gait speed. Binary logistic regression identified clinical parameters associated with sarcopenia in MHD Results：Sarcopenia patients showed lower serum rT3 levels than non-sarcopenia controls (P=0.022). Both univariate (P<0.05) and multivariate analyses confirmed an independent inverse association between serum rT3 levels and sarcopenia risk （OR=0.495，95％CI=0.268~0.915，P=0.024）. Conclusion serum rT3 levels in MHD patients are independently linked to sarcopenia, with the underlying mechanism.

Key words: Reverse Triiodothyronine, Sarcopenia, Maintenance Hemodialysis