Efficacy of glutamine supplementation in postoperative patients undergoing hepatic surgery: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The efficacy and safety of glutamine supplementation in patients receiving hepatic surgery remain controversial. METHODS: A search strategy incorporating the terms "glutamine", "liver transplantation", and "hepatectomy" was applied across eight literature databases. Study quality was evaluated via the Risk of Bias 2.0 (ROB 2.0) tool, while statistical analyses were undertaken through R 4.4.1. RESULTS: 18 studies involving 1198 patients were encompassed. Meta-analysis revealed that immune factors Immunoglobulin A (IgA), Immunoglobulin M (IgM), Cluster of Differentiation 3 (CD3), Cluster of Differentiation 4 (CD4), and CD4/Cluster of Differentiation 8 (CD8) were significantly higher in the glutamine cohort than those in the control cohort(SMD = 1.21, 0.25, 1.52, 0.99, and 0.77). Levels of inflammatory markers C-Reactive Protein (CRP), Tumor Necrosis Factor-alpha (TNF-α), Interleukin-1 (IL-1), Interleukin-6 (IL-6), and Interleukin-8 (IL-8) were markedly lower in the glutamine group (SMD = -2.03, -3.29, -1.86, -2.20, and -2.29). The glutamine cohort also exhibited a significant decrease in liver function indicators Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) (SMD = -1.03 and -1.05), while Cholinesterase (CHE) levels were significantly elevated (SMD = 0.61). Serum protein levels, including Albumin (ALB), Prealbumin (PA), and Total Protein (TP), were significantly higher in patients receiving glutamine (SMD = 0.68, 1.09, and 0.81). In addition, Adverse Events (AEs), defined as overall postoperative complications, were significantly less frequent in the glutamine group (RR = 0.59, 95% CI 0.44‒0.79). CONCLUSION: Glutamine supplementation in postoperative hepatic surgery patients enhances immune function, reduces inflammation, improves liver function, and decreases the incidence of AEs.