Stepwise Incremental Hemodialysis and Low-Protein Diet Supplemented with Keto-Analogues Preserve Residual Kidney Function: A Randomized Controlled Trial.

Background

Rapid loss of residual kidney function (RKF) is associated with unfavorable outcomes. We conducted an RCT to compare the effects on RKF preservation of incremental HD between once-weekly HD (1-WHD) and twice-weekly HD (2-WHD).

Methods

ESKD patients with an eGFR of 5-10 mL/min/1.73 m2 and urine output of ≥800 mL/day were randomly assigned to receive either once-weekly HD (1-WHD) or twice-weekly HD (2-WHD) for 12 months. Patients in the 1-WHD group were prescribed once-weekly HD combined with low-protein diet (0.6 g/kg/day) supplemented with keto-analogues (KAs) 0.12 g/kg/day. In the 2-WHD group, patients received twice-weekly HD with a regular-protein diet. Primary outcomes were changes in RKF by renal clearance and urine volume. Nutritional status, muscle parameters, and quality of life (QoL) were also assessed.

Results

A total of 30 incident HD patients were randomized. Baseline RKF, urine volume, and demographic were not different between groups. After 3 months, urine volume was significantly higher in the 1-WHD group than in the 2-WHD group (1921 ± 767 mL/day vs. 1305 ± 599 mL/day, p = 0.02), and these significant findings persisted throughout the entire study period. For RKF, 1-WHD also had a lesser decline in urinary urea (CUrea) and creatinine clearance (CCr) than 2-WHD, with statistically significant differences observed from months 6-12. By month 6, the 1-WHD group exhibited significantly higher CUrea and CCr compared to the 2-WHD group, with CUrea at 3.2 ± 2.3 vs. 1.7 ± 1.0 mL/min (p = 0.03) and CCr at 5.9 ± 3.6 vs. 3.8 ± 1.4 mL/min (p = 0.04), respectively. Serum albumin levels, skeletal muscle mass, anemia status, metabolic parameters, protein-bound uremic toxins, and QoL scores were comparable between the two groups.

Conclusions

Incremental HD, starting with once-weekly HD combined with protein restriction supplemented with KAs, appears to better preserve RKF among incident HD patients compared to twice-weekly HD with a regular-protein diet. This HD regimen was also associated with safety in metabolic and nutritional profiles.