| خلاصه مقاله | Background and Aims: β-Hydroxy-β-methyl butyrate (HMB) is a metabolite of leucine that has anti-catabolic effects on muscle tissue. Critical illness is associated with muscle wasting which may impair recovery and quality of life. In this review, we summarize the current findings regarding HMB supplementation's effect on muscle quality and protein metabolism in critically ill subjects.
Methods: The Web of Science, Scopus and PubMed databases were systematically searched to identify relevant studies published until January 2024. Studies were included if they compared HMB supplementation with placebo or standard care in adult critically ill patients. Data extraction, quality assessment, and narrative synthesis were performed according to standard methods.
Results: This review included eight studies with a total of 323 individuals. HMB supplementation was administered from 1.5 to 3 g/day for 7 to 28 days. The results showed that HMB supplementation improved muscle quality, as measured by muscle mass, strength, and function in critically ill patients. HMB supplementation also modulated protein metabolism, as indicated by reduced blood and urinary urea, increased plasma and muscle free amino acids, and enhanced muscle protein synthesis and breakdown rates. The quality of the studies was low to moderate, and the heterogeneity was high due to different HMB dosages, timing, and co-interventions.
Conclusion: Evidence suggests that HMB supplementation may enhance muscle quality and protein metabolism in patients with critical illness. However, more high-quality studies are needed to confirm the efficacy, safety, and optimal protocol of HMB supplementation in this population. |