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

Abstract

Background: Amino acid (AA) depletion during dialysis deteriorates the protein-energy status of haemodialysis (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 a serum albumin level of 3.5-3.9 mg/dl despite 7-point subjective global assessment in category A or a 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 in the first 15 minutes after HD initiation with high-flux dialyser through the end of the session. Similar parenteral nutrition compositions containing the same total amount of glucose and AA were rapidly added into the venous drip chamber within the last hour of HD in the acute load group (n = 24). The 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: The mean age of patients was 68.9 ± 12.7 years and the average body mass index was 22.8 ± 4.4 kg/m² with 45.8% being men. After 3 months, serum albumin levels were significantly elevated in continuous infusion (P = .001) whereas it was unchanged in the acute load (P = .13). Despite comparable energy and protein intake, total body muscle mass was also increased in the continuous infusion group at 3 months (P = .03) compared with no significant change in the acute load group (P = .45). The amount of AA loss into the dialysate was similar between the two groups (P = .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 = .61) and valine (P = .09) were comparable between the 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 a longer period of study (TCTR20230401003).