Effects of Branched-Chain Amino Acid–Rich Supplementation on EWGSOP2 Criteria for Sarcopenia in Older Adults: A Systematic Review and Meta-Analysis

Abstract

<h3>Objectives</h3> Protein supplements can improve the loss of muscle in older people. However, existing reviews have pooled supplements from amino acids to food products together to examine their effects and did not evaluate muscle strength, muscle mass, and physical performance based on official criteria. According to criteria recommended by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2), we analyzed the effects of branched-chain amino acid (BCAA)-rich supplements on muscle strength, muscle mass, and physical performance in older people. <h3>Data Source(s)</h3> We searched PubMed, Embase, Cochrane Library, and CINAHL from inception until March 2021. <h3>Study Selection</h3> Randomized controlled trials (RCTs) that examined the effect of BCAA-rich supplements on older people according to measurement tools recommended by the EWGSOP2 were included. <h3>Data Extraction</h3> Random-effects meta-analyses were performed. Subgroup analyses were stratified by participant and supplementation characteristics. Meta-regression analyses were performed to examine the effect of continuous variables. <h3>Data Synthesis</h3> Thirty-five studies were included in the current meta-analysis. Quality assessment revealed that only 14 of 35 RCTs had some concerns regarding overall risk of bias. The overall standardized mean difference in muscle strength, muscle mass, and physical performance between the supplement and control groups was (SMD: 0.35, 95% CI = [0.15, 0.55], P = 0.0007), (SMD: 0.25, 95% CI = [0.10, 0.40], P = 0.0008), and (SMD: 0.20, 95% CI = [0.05, 0.46], P = 0.12), respectively. Subgroup analysis revealed that supplements improved handgrip strength in essential amino acids more significantly than whey protein in older people. Meta-regression analysis showed a significant linear relationship between the improvement in handgrip strength and body mass index. <h3>Conclusions</h3> BCAA-rich supplements may exert beneficial effects on muscle strength and mass of older people. However, owing to high heterogeneity, inferences from the results must be made with caution. <h3>Author(s) Disclosures</h3> There are no financial benefits to the authors associated with this work. This work has not been presented previously.