The compound β-hydroxy-β-methyl butyrate (HMB) is proposed to increase or mitigate the loss of skeletal muscle and improve muscle function. We undertook a review of systematic reviews of HMB supplementation to promote gains or mitigate muscle loss in ageing and clinical populations. Following PRISMA guidelines, we searched for systematic reviews reporting the effect of HMB in our target populations. Dual-energy X-ray absorptiometry (DXA) measured lean soft-tissue mass (LSTM) was accepted as a proxy for muscle. We identified 15 systematic reviews that met our inclusion criteria, which were independently evaluated. The methodological quality of the reviews was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR), and standardized effectiveness statements were generated. Five of 15 studies found some evidence that HMB augmented LSTM; the remaining 10 studies reported some evidence favouring no difference (6/10 studies) or insufficient evidence to determine an effect (4/10 studies). Of the 12 studies that evaluated strength, 4/12 found some evidence, 5/12 found some evidence of no effect with one article finding some evidence in favour of patients in peri-hospitalized and no evidence for those that are community-dwelling, 4/12 had insufficient evidence to determine an effect, and 1/12 had insufficient evidence. No]study reported a positive effect of HMB on physical function; however, 2/10 studies found some evidence favouring no effect, and 7/10 studies reported insufficient evidence to determine an effect. The effectiveness of HMB supplementation in augmenting LSTM was heterogeneous, with most reviews finding no effect or inconclusive evidence to determine an effect. Most reviews concluded that HMB supplementation did not affect strength outcome measures or studies were inconclusive. The current evidence is insufficient to assess the impact of HMB supplementation on functional outcome measures. Our analysis shows minor, inconsistent support for HMB as part of an oral nutritional supplement or as a stand-alone supplement (or combined with other amino acids) to increase or promote retention of LSTM, improve strength, and no evidence that it improves physical function in older persons or clinical populations.

中文翻译：

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β-羟基-β-甲基丁酸补充剂在衰老和临床实践中的系统评价综述

提出了化合物β-羟基-β-甲基丁酸酯（HMB）以增加或减轻骨骼肌的损失并改善肌肉功能。我们对 HMB 补充剂的系统评价进行了回顾，以促进衰老和临床人群中的肌肉损失或减轻肌肉损失。根据 PRISMA 指南，我们搜索了系统评价报告 HMB 在我们的目标人群中的影响。双能 X 射线吸收法 (DXA) 测量的瘦软组织质量 (LSTM) 被接受为肌肉的代表。我们确定了 15 篇符合我们纳入标准的系统评价，并对其进行了独立评估。使用 A Measurement Tool to Assess Systematic Reviews (AMSTAR) 评估审查的方法学质量，并生成标准化的有效性声明。15 项研究中有 5 项发现了 HMB 增强 LSTM 的一些证据；其余 10 项研究报告了一些证据表明没有差异（6/10 研究）或证据不足以确定效果（4/10 研究）。在评估强度的 12 项研究中，4/12 发现了一些证据，5/12 发现了一些无效的证据，一篇文章发现了一些有利于住院期间患者的证据，而没有证据表明社区居住的患者，4 /12 没有足够的证据来确定效果，而 1/12 的证据不足。没有研究报告 HMB 对身体功能有积极影响；然而，2/10 的研究发现一些证据支持没有效果，7/10 的研究报告没有足够的证据来确定效果。补充 HMB 在增强 LSTM 方面的效果是异质的，大多数评论没有发现任何影响或不确定的证据来确定影响。大多数评论得出结论，HMB 补充剂不会影响力量结果测量或研究没有结论。目前的证据不足以评估补充 HMB 对功能结果测量的影响。我们的分析显示，对于 HMB 作为口服营养补充剂的一部分或作为独立补充剂（或与其他氨基酸组合）以增加或促进 LSTM 的保留、提高力量、没有证据表明它可以改善身体机能的支持很少且不一致在老年人或临床人群中。目前的证据不足以评估补充 HMB 对功能结果测量的影响。我们的分析显示，对于 HMB 作为口服营养补充剂的一部分或作为独立补充剂（或与其他氨基酸组合）以增加或促进 LSTM 的保留、提高力量、没有证据表明它可以改善身体机能的支持很少且不一致在老年人或临床人群中。目前的证据不足以评估补充 HMB 对功能结果测量的影响。我们的分析显示，对于 HMB 作为口服营养补充剂的一部分或作为独立补充剂（或与其他氨基酸组合）以增加或促进 LSTM 的保留、提高力量、没有证据表明它可以改善身体机能的支持很少且不一致在老年人或临床人群中。