Table4_Effects of blood flow restriction training on bone metabolism: a systematic review and meta-analysis.xlsx

Introduction: The efficacy of low-intensity blood flow restriction (LI-BFR) training programs in bone metabolism remains unclear compared to low-intensity (LI) training and high-intensity (HI) training. The aim of this review was to quantitatively identify the effects of LI-BFR training on changes in bone formation markers (i.e., bone-specific alkaline phosphatase, BALP), bone resorption (i.e., C-terminal telopeptide of type I collagen, CTX) and bone mineral density (BMD) compared with conventional resistance training programmes. Additionally, the effectiveness of walking with and without BFR was assessed.
Methods: PubMed, Scopus, SPORTDiscus, Web of Science and Google Scholar databases were searched for articles based on eligibility criteria. Review Manager Version 5.4 was used for Meta-analysis. Physiotherapy Evidence Database (PEDro) was applied to assess the methodological quality of studies.
Results: 12 articles were included in the meta-analysis, with a total of 378 participants. Meta-results showed that compared with LI training, LI-BFR training induced greater increments in BALP (young adults: MD = 6.70, p < 0.001; old adults: MD = 3.94, p = 0.002), slight increments in BMD (young adults: MD = 0.05, p < 0.00001; old adults: MD = 0.01, p < 0.00001), and greater decrements in CTX (young adults: MD = −0.19, p = 0.15; old adults: MD = −0.07, p = 0.003). Compared with HI training, LI-BFR training produced smaller increments in BALP (young adults: MD = −6.87, p = 0.24; old adults: MD = −0.6, p = 0.58), similar increments in BMD (MD = −0.01, p = 0.76) and similar decrements in CTX (young adults: MD = 0, p = 0.96; old adults: MD = −0.08, p = 0.13). Although there were only two studies on walking training intervention, walking training with BFR had a better effect on bone metabolism than training without BFR.
Discussion: In conclusion, LI-BFR training induces greater improvements in bone health than LI training, but is less effective than HI training. Therefore, LI-BFR training may be an effective and efficient way to improve bone health for untrained individuals, older adults, or those undergoing musculoskeletal rehabilitation.
Clinical Trial Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42023411837].

引言：相较于低强度（LI）训练与高强度（HI）训练，低强度血流限制（low-intensity blood flow restriction, LI-BFR）训练方案在骨代谢方面的疗效仍不明确。本综述旨在定量分析相较于传统抗阻训练方案，LI-BFR训练对骨形成标志物（即骨特异性碱性磷酸酶（bone-specific alkaline phosphatase, BALP））、骨吸收标志物（即I型胶原C端肽（C-terminal telopeptide of type I collagen, CTX））及骨密度（bone mineral density, BMD）变化的影响。此外，本研究还评估了附加与不附加BFR的步行训练的有效性。
方法：基于纳入标准，在PubMed、Scopus、SPORTDiscus、Web of Science及Google Scholar数据库中检索相关文献。采用Review Manager 5.4版本进行荟萃分析，采用物理治疗证据数据库（Physiotherapy Evidence Database, PEDro）评估研究的方法学质量。
结果：本荟萃分析共纳入12篇文献，总计378名受试者。荟萃分析结果显示：相较于LI训练，LI-BFR训练可使BALP水平显著升高（青年人群：均差MD=6.70，p<0.001；老年人群：MD=3.94，p=0.002），小幅提升BMD（青年人群：MD=0.05，p<0.00001；老年人群：MD=0.01，p<0.00001），并可更显著地降低CTX水平（青年人群：MD=-0.19，p=0.15；老年人群：MD=-0.07，p=0.003）。相较于HI训练，LI-BFR训练对BALP的提升幅度更小（青年人群：MD=-6.87，p=0.24；老年人群：MD=-0.6，p=0.58），对BMD的提升效果相近（MD=-0.01，p=0.76），对CTX的降低效果亦无显著差异（青年人群：MD=0，p=0.96；老年人群：MD=-0.08，p=0.13）。尽管仅纳入2项步行训练干预研究，但附加BFR的步行训练对骨代谢的改善效果优于无BFR的步行训练。
讨论：综上，LI-BFR训练对骨骼健康的改善效果优于LI训练，但劣于HI训练。因此，LI-BFR训练或可作为一种高效便捷的骨骼健康改善手段，适用于未接受过训练的人群、老年人或正接受肌肉骨骼康复的患者。
临床试验注册：[https://www.crd.york.ac.uk/prospero/]，注册号[CRD42023411837]。