Skeletal muscle changes in older patients undergoing online hemodiafiltration.

Background & Aims: Skeletal muscle mass (SMM) and function are negatively affected in chronic kidney disease (CKD). SMM and the assessment of muscle strength and functionality are indicators of clinical and nutritional status. We aimed to evaluate older patients undergoing online hemodiafiltration (OL-HDF), using muscle ultrasound (US) to monitor the SMM, correlating findings with strength and physical performance.

Methods: This is a prospective cohort that included patients on OL-HDF, evaluated at admission (T0), 6 months (T1), and 12 months (T2) by anthropometric data, calf circumference (CC) measurement, muscle strength measured by handgrip (HGS) and functionality by gait speed. Muscle US was used for serial assessment of the quantity and quality of SMM during the 12-month follow-up. The main outcome was change in the following muscle parameters: quadriceps muscle thickness (QT), rectus femoris cross-sectional area (RF-CSA), pennation angle (PA) and muscle echogenicity, evaluated by the US.

Results: Thirty subjects were included (75.9 ± 7.8 years, 76.7% men). Over time, there was a significant reduction in CC (p < 0.01) in both sexes and gait speed only in men (p < 0.01). The reduction of SMM was observed in both sexes by the assessment of QT and RF-CSA (p < 0.01). There was an increased muscle echogenicity in both men (p < 0.01) and women (p = 0.01). The percentage of SMM loss of the RF-CSA in 12 months was -19.3 ± 6.9% (95% CI: 15.2-23.2; p < 0.01) in men and -23.0 ± 8.2% (95% CI: 12.8-31.1; p < 0.01) in women.

Conclusion: Muscle US, a bedside, non-invasive, accessible, and inexpensive tool, can be applied for assessment of the accelerated loss of SMM in older patients with CKD on dialysis.