Effects of beta-hydroxy-beta-methyl butyrate (HMB) supplementation on biochemical muscle injury indices in adults: a systematic review and meta-analysis of randomized controlled trials

The impact of beta-hydroxy-beta-methylbutyrate (HMB) supplementation on muscle injury indices is not entirely clear due to contradictory information about the subject. Therefore, the present systematic review and meta-analysis was conducted to summarize current findings on the effect of HMB supplementation on muscle injury indices in adults. We conducted a comprehensive search of PubMed, Scopus, Web of Science databases, and Google Scholar to identify relevant randomized controlled trials (RCTs). We included RCTs assessing HMB supplementation’s effects on creatine kinase (CK) and lactate dehydrogenase (LDH) levels. Weighted mean differences (WMD) and 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was assessed with Cochran’s Q test and quantified by I² statistic. To evaluate certainty of evidence, we applied the GRADE framework. Subgroup and meta-regression analyses were also performed to explore potential sources of heterogeneity.

Fourteen trials involving six hundred eighty-one participants were included. HMB supplementation reduced CK (WMD = − 37.94 U/L; 95% CI − 65.63 to − 10.26; I² = 80.5%) and LDH (MD = − 16.38 U/L; 95% CI − 35.06 to 2.29; I² = 84.7%) levels compared to placebo, although the effect on LDH was not statistically significant. The certainty of the evidence was very low for both outcomes. Further high-quality studies are needed to confirm these findings.