The effects of beta-hydroxy-beta-methyl butyrate supplementation in surgical patients: a systematic review and meta-analysis of randomized controlled trials.

Background: Beta-hydroxy-beta-methylbutyrate (HMB) is a nutritional supplement that has demonstrated favorable effects on restoring muscle mass. However, evidence to support its use in patients underlying surgery remains unclear. We aimed to conduct a systematic review and meta-analysis of HMB in this population to ascertain its effect. Methods: We searched PubMed, EMBASE, Web of Science, the China National Knowledge Infrastructure, Wanfang, and the Cochrane Library for randomized controlled trials (RCTs) focused on surgical patients receiving HMB compared to controls. The last search was March 15, 2025. Length of stay (LOS) and postoperative complications were the primary outcomes. We assessed study quality and performed subgroup analysis, sensitivity analysis, and the GRADE system to explore potential heterogeneity. Results: Eleven RCTs with 575 patients were included. There are some differences in study design, HMB protocols, and muscle measurements among these trials. Overall, HMB significantly reduced the hospital LOS (MD -0.90 days; 95% CI, -1.79 to -0.01; Conclusion: HMB supplement seems to significantly improve hospital LOS and postoperative complications, as well as some outcomes of muscle measurements and physical function. However, due to the significantly heterogeneity among the included studies, more well-designed RCTs are needed to confirm our findings.