Nutritional outcomes between different techniques of intradialytic amino acid replacement: a randomized controlled trial

Abstract

Abstract Background Amino acid (AA) depletion during dialysis deteriorates protein-energy status of hemodialysis (HD) patients. This study aimed to determine whether intradialytic amino acid (IDAA) replacement by continuous infusion versus acute load could provide better nutritional outcomes. Methods HD patients with mild protein-energy wasting, defined as serum albumin level of 3.5–3.9 mg/dL despite 7-point SGA in category A or malnutrition inflammation score ≤ 5, were randomly assigned to receive IDAA by continuous infusion or acute load for 3 months. In continuous infusion (n = 24), 50% glucose followed by 7.2% branched-chain enriched AA solution were instilled at first 15 mins after HD initiation with high-flux dialyzer through the end of session. Similar parenteral nutrition compositions containing the same total amount of glucose and AA were rapidly added into venous drip chamber within the last hour of HD in the acute load group (n = 24). Primary outcome was the change in serum albumin level. Secondary outcomes were changes in muscle parameters, and plasma as well as dialysate AA concentrations. Results Mean age of patients was 68.9 ± 12.7 years and average body mass index of 22.8 ± 4.4 kg/m2 with 45.8% men. After 3 months, serum albumin levels were significantly elevated in continuous infusion (P = 0.001) whereas it was unchanged in acute load (P = 0.13). Despite comparable energy and protein intake, total-body muscle mass was also increased in continuous infusion group at 3 months (P = 0.03) compared with no significant change in acute load group (P = 0.45). Amount of AA loss into dialysate was similar between two groups (P = 0.17). At post-dialysis, most plasma essential and non-essential AA levels were significantly lower in patients receiving continuous infusion than acute load while branched-chain AA concentrations including leucine (P = 0.61) and valine (P = 0.09) were comparable between two groups. Despite enhancing muscle mass in continuous infusion, handgrip strength and gait speed were unaltered in both techniques of IDAA replacement. Conclusions IDAA using continuous infusion appears to be superior to acute load in terms of serum albumin and muscle mass improvement. The impact of IDAA on hard clinical outcomes may require larger scale with longer period of study (TCTR20230401003).