Effect of β-Hydroxy-β-methyl butyrate (HMB) Supplementation on Muscle Changes and Clinical Outcomes with Sonography Assessment in ICU: A Systematic Review

Abstract

Introduction. To evaluate the effects of β-Hydroxy-β-methyl butyrate (HMB) supplementation on muscle changes in critically ill patients, focusing on muscle mass, strength, and functional recovery.
Methods. A comprehensive literature search was conducted -across multiple electronic databases, including PubMed, Scopus, and Web of Science, from database inception to December 2023. Data extraction was performed using a standardized form, and quality assessment was -assessed using the Newcastle-Ottawa Scale (NOS).
Results. Six randomized controlled trials (RCTs), comprising 398 participants, were included in the analysis. The studies enrolled 
intensive care unit (ICU) patients with trauma, liver cirrhosis, or those requiring mechanical ventilation. The interventions included HMB alone or HMB-containing formulations combined with other nutritional supplements, such as arginine and glutamine. The HMB dose was 3 g/d, and the duration of supplementation ranged from 10 to 84 days. Regarding muscle mass changes, no significant differences in diaphragm or quadriceps muscle thickness were found in one study (P = .87). In contrast, other studies demonstrated marginal improvements in muscle preservation. For example, one study found a reduction in femoral muscle volume of 11.4% in the HMB group compared with 14.4% in the control group, although this difference was not statistically significant (P = .18). However, a subgroup analysis of patients with lower SOFA scores showed that HMB supplementation significantly preserved muscle volume (P = .047). In another trial, HMB supplementation significantly improved quadriceps thickness (P < .05) compared with placebo. Additionally, significant improvements in muscle function were observed in the HMB group, including better performance in the chair-stand and six-minute walk tests (P < .05). HMB supplementation also reduced net protein breakdown and increased amino acid production in muscle, although these metabolic improvements did not consistently translate into measurable preservation of muscle mass. 
Conclusions. HMB supplementation in critically ill patients may offer modest benefits in preserving muscle mass and improving 
functional recovery, particularly in patients with less severe illness.