Abstract: Objective To investigate the longitudinal changes in body composition of patients undergoing maintenance hemodialysis by BIA. Methods Data was collected from patients underwent regular hemodialysis in the hemodialysis center of Yantai Yeda Hospital from January 1, 2020 to February 28, 2023. Data collected from a total number of 120 patients, 61 males and 59 females, aged 29-84 (56.23±13.52), and 50 patients aged over 60. Participants were selected from patients who completed two body composition analysis, and each analysis was completed at least one year apart. Body composition analysis and biochemical indicators such as albumin, prealbumin, creatinine, urea were collected in the month of completing the body composition analysis. Compared the results of laboratory biomarkers and body composition from two tests. Results Compared with one year before, significant differences were discovered that the level of prealbumin (P<0.05) decreased, while ferritin, hemoglobin and creatinine (P<0.05) increased. Body composition analysis showed that indicators like Body Cell Mass, protein, Skeletal Muscle Mass, Fat Free Mass, mineral and Phase Angle were significantly decreased (P<0.05), while Visceral Vat Area increased (P<0.05). After stratified analysis by sex, significant differences of human body composition between different genders were found;Albumin was significantly positively correlated with Body Cell Mass, protein, Skeletal Muscle Mass and Phase Angle in two groups (P<0.05). Conclusion Compared to biochemical indicators, changes in body composition parameters such as body cell mass, protein, skeletal muscle mass, and phase angle are more significant in the longitudinal observation of patients undergoing maintenance hemodialysis. The importance of these parameters in the long-term nutritional management of hemodialysis patients should be emphasized.

Key words: renal dialysis, nutrition management, bioelectrical impedance