Association Between Electrical Conductivity and Global Impedance Measured by EIT with Muscle Mass Scores in Sarcopenia

Electrical impedance tomography (EIT) imaging is used for quantitative assessment of muscle mass and function in elderly with sarcopenia. However, the differences in EIT-derived parameters between patients with and without sarcopenia and the correlation between parameters and muscle function scores are unclear. Thirty-one sarcopenic and healthy subjects were recruited in this work, and maximal handgrip strength (MHG), maximal isometric voluntary contraction (MVC), and SARC-F scale of all individuals were used for muscle function scoring. The electrical conductivity and global impedance values of the gastrocnemius muscle were calculated by EIT, and then the correlation with muscle function scores was analyzed. The results showed that the mean amplitude of conductivity was ordered in the young (0.0041) > elderly (0.0034) > sarcopenia (0.0029) group, while the results for global impedance were the opposite. In addition, conductivity showed a strong positive correlation with muscle function scores (r=0.619, p<0.001), while global impedance showed a moderate negative correlation with scores (r=-0.469, p<0.05). The results demonstrate the potential of EIT imaging technology for sarcopenia diagnosis and quantitative assessment of muscle mass and function. In the future, we will expand the number of subjects, determine the independent influencing factors related to sarcopenia, and construct an accurate diagnosis and functional assessment model.