Objective  To investigate the mediating effect of phase angle between muscle strength and muscle function in maintenance hemodialysis (MHD) patients, aiming to provide a reference basis for clinical improvement of muscle strength and muscle function in MHD patients. Methods  Random sampling was used to collect patients undergoing outpatient MHD in the Wenjiang Hemodialysis Room of the Department of Nephrology, West China Hospital, Sichuan University between September and December 2023 as the subjects of this study. Muscle strength was assessed by handgrip strength, muscle function was assessed by Short Physical Performance Battery (SPPB), and phase angle was measured by bioelectrical impedance analysis. The mediating effect of phase angle between muscle strength and muscle function was analyzed. Results  A total of 239 MHD patients were included, including 125 males (52.3%) and 114 females (47.7%). The mean phase angle of MHD patients was (5.77±1.17)°, 89 patients (37.2%) showed decreased muscle strength, and 109 patients (45.6%) showed muscle hypoplasia. Spearman’s correlation analyses showed that phase angle was significantly and positively correlated with both handgrip strength and SPPB in MHD patients (P<0.001). The results of mediation effect analysis showed that handgrip strength was able to positively predict phase angle (β=0.535, P<0.001); handgrip strength was able to positively predict SPPB (β=0.481, P<0.001); phase angle was able to positively predict SPPB (β=0.296, P<0.001); and when both handgrip strength and phase angle entered in the regression equation, both handgrip strength (β=0.392, P<0.001) and phase angle (β=0.165, P<0.05) could positively predict SPPB. Phase angle in MHD patients partially mediated the association between muscle strength and muscle function, with the mediating effect accounting for 32.5% of the total effect. Conclusions  There is a close relationship between phase angle, muscle strength and muscle function in MHD patients, and muscle strength can affect muscle function directly or indirectly through phase angle. Medical professionals should pay attention to the muscle function of MHD patients and further improve their muscle function by improving their phase angle and muscle strength.

Citation： CHEN Yang, YANG Yujie, QIU Ying, YUAN Huaihong. Mediating effect of phase angle between muscle strength and muscle function in patients with maintenance hemodialysis. West China Medical Journal, 2025, 40(7): 1061-1066. doi: 10.7507/1002-0179.202405217 Copy

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