Background

Findings regarding the effects of resistance training (RT) on muscle strength, serum level of IGF-1, and its binding proteins are contradictory. To resolve this contradiction, we performed a systematic review and meta-analysis to investigate the effects of RT on muscle strength, the levels of serum IGF-1, and IGF-binding protein-3 in the elderly and aged.

Materials and methods

The PubMed, CINAHL, Medline, Google Scholar, and Scopus databases and reference lists of included studies were systematically searched to identify randomized controlled trials (RCTs) comparing subjects who underwent RT and control individuals up to May 15, 2020. This study was performed following the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses guidelines. We identified and analyzed 11 eligible trials in this meta-analysis.

Results

Pooled data displayed an overall significant elevation in IGF-1 (mean difference (MD): 17.34 ng/ml; 95% confidence interval (CI): 7.23, 27.46) and in muscle strength in leg press (SMD: 0.82; 95% CI: 0.30, 1.34) and bench press (SMD: 0.82; 95% CI: 0.42, 1.23) following RT. By contrast, the pooled estimate showed a non-significant elevation in IGFBP-3 (MD: 0.13 ng/ml; 95% CI: − 39.39, 39.65). Subgroup analysis revealed that the elevation in serum IGF-1 levels after RT was significant only in women (MD: 19.30 ng/ml); moreover, it increased after intervention durations of both > 12 weeks (MD: 21.98 ng/ml) and of ≤ 12 weeks (MD: 15.31 ng/ml).

Conclusion

RT was associated with elevated muscle strength. Moreover, RT was correlated with increased serum levels of IGF-1 among women and among those who received the training for ≤ 12 weeks or > 12 weeks. Further studies are required to elucidate the mechanisms underlying the impact of RT on IGF-1, IGFBP-3, and muscle strength.

中文翻译：

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抗阻训练对健康老年受试者肌肉力量、胰岛素样生长因子 1 和胰岛素样生长因子结合蛋白 3 的影响：随机对照试验的系统评价和荟萃分析

背景

关于阻力训练 (RT) 对肌肉力量、IGF-1 血清水平及其结合蛋白的影响的发现是相互矛盾的。为了解决这一矛盾，我们进行了系统回顾和荟萃分析，以研究放疗对老年人和老年人肌肉力量、血清 IGF-1 和 IGF 结合蛋白-3 水平的影响。

材料和方法

对 PubMed、CINAHL、Medline、Google Scholar 和 Scopus 数据库以及纳入研究的参考列表进行了系统搜索，以确定比较截至 2020 年 5 月 15 日接受放疗的受试者和对照个体的随机对照试验 (RCT)。本研究如下进行系统评价和元分析报告的首选项目指南。我们在这项荟萃分析中确定并分析了 11 项符合条件的试验。

结果

汇总数据显示 IGF-1（平均差异 (MD)：17.34 ng/ml；95% 置信区间 (CI)：7.23、27.46）和腿部推举的肌肉力量（SMD：0.82；95% CI）总体显着升高: 0.30, 1.34) 和卧推 (SMD: 0.82; 95% CI: 0.42, 1.23) 在 RT 之后。相比之下，汇总估计值显示 IGFBP-3 不显着升高（MD：0.13 ng/ml；95% CI：- 39.39, 39.65）。亚组分析显示，放疗后血清 IGF-1 水平升高仅在女性中显着（MD：19.30 ng/ml）；此外，在> 12 周（MD：21.98 ng/ml）和≤ 12 周（MD：15.31 ng/ml）的干预持续时间后，它增加。

结论

放疗与肌肉力量升高有关。此外，RT 与女性和接受训练 ≤ 12 周或 > 12 周的女性血清 IGF-1 水平升高相关。需要进一步的研究来阐明 RT 对 IGF-1、IGFBP-3 和肌肉力量影响的潜在机制。