Distinct Trajectories of Muscle Mass Changes in Patients on Hemodialysis

Background: Muscle wasting is a common complication in hemodialysis (HD) patients, often resulting in reduced quality of life and increased mortality. This study aimed to identify distinct trajectories of lean tissue index (LTI) over time and explore the clinical factors associated with these patterns in HD patients. Methods: This prospective cohort study analyzed 283 HD patients who underwent body composition monitoring (BCM) at least three times over intervals of 6-12 months. The percentage change in appendicular skeletal muscle (ASM)/m2 was calculated, and trajectory modeling were performed based on Bayesian Information Criterion values. Clinical factors associated with significant muscle loss were evaluated. For nutritional status assessment, we used geriatric nutritional index (GNRI). Results: The overall mean age was 63.5 ± 12.1 years, with 59.4% having diabetes and 52.7% being male. The median dialysis duration at the time of the first BCM study was 7 months. During the mean follow-up of 24.5 ± 9.2 months, BCM monitoring frequency was: 3 times (34.6%), 4 times (39.2%), 5 times (23.3%), and ≥6 times (2.8%). Three distinct LTI trajectories were identified: increasing (13.8%), mild decline (59.4%), and progressive decline (26.9%). Mean annual changes in muscle mass for these 3 groups were +11.9 ± 7.4%, -2.3 ± 4.8%, and -12.8 ± 7.4%, respectively. Patients in the progressive decline group were significantly older, had multiple cardiovascular comorbidities, higher systolic blood pressure, and elevated inflammation levels. Additionally, they had a significantly lower GNRI score, with approximately 35% having a GNRI below 90. After adjusting for multiple risk factors, a lower GNRI score was significantly associated with an increased risk of progressive muscle mass decline. Conclusion: This study identified three distinct muscle mass trajectories in HD patients, with progressive decline observed in 27%. Managing modifiable factors particularly nutritional status is crucial to mitigate muscle loss and improve clinical outcomes. Funding: Clinical Revenue Support