Applied Physiology and Nutrition Research Group, School of Physical Education and Sport, Rheumatology Division, Faculdade de Medicina FMUSP, Universidade de São Paulo, Av. Dr. Arnaldo, 455, 3º andar, São Paulo, SP, 01246-903, Brazil.
Department of Sport, Exercise and Nutrition, Galway Mayo Institute of Technology, Galway, Ireland.
Sports Med. 2022 Dec;52(12):2889-2908. doi: 10.1007/s40279-022-01718-8. Epub 2022 Jul 23.
Circulating biomarkers are often used to investigate the bone response to an acute bout of exercise, but heterogeneity in factors such as study design, quality, selected biomarkers, and exercise and participant characteristics render it difficult to synthesize and evaluate available evidence.
The aim of this study was to quantify the effects of an acute exercise bout on bone biomarkers, along with the influence of potential moderators such as participant, exercise, and design characteristics, using a systematic review and meta-analytic approach.
The protocol was designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) guidelines and prospectively published. Seven databases were systematically searched in accordance with predefined eligibility criteria. Bayesian three-level hierarchical meta-analysis models were used to explore the main effects of acute exercise on bone biomarkers, as well as potential moderating factors. Modelled effect sizes were interpreted according to three metrics, namely (1) evidence of an effect (defined by whether, or how much of, the credible interval [CrI] included zero); (b) the size of that effect (threshold values of 0.01, 0.2, 0.5 and 0.8 were used to describe effect sizes as very small, small, medium and large, respectively); and (c) the level of certainty in the estimated effect (defined using the GRADE framework).
Pooling of outcomes across all designs and categories indicated that an acute bout of exercise increased bone resorption (ES 0.10, 95% CrI 0.00-0.20) and formation (ES 0.05, 95% CrI 0.01-0.08) markers but the effects were very small and highly variable. Furthermore, moderator analyses revealed the source of some of this variability and indicated that exercise type and impact loading influenced the bone resorptive response. A moderate increase in C-terminal telopeptide of type 1 collagen (CTX-1) was observed in response to cycling (ES 0.65, 95% CrI 0.20-0.99), with greater durations and more work leading to larger CTX-1 increases. CTX-1 response peaked within 15 min and 2 h after the exercise bout. Other exercise types did not influence CTX-1. Changes to all bone formation markers were very small and transient, with the very small increases returning to baseline within 15 min of exercise cessation. No major trends for bone formation markers were identified across any of the moderating categories investigated. Certainty of evidence in most outcomes was deemed to be low or very low.
The large influence of an acute bout of prolonged cycling on the bone resorption marker CTX-1, alongside the lack of a response of any biomarker to resistance or high-impact exercise types, indicate that these biomarkers may be more useful at investigating potentially osteolytic aspects of exercise, and raises questions about their suitability to investigate the osteogenic potential of different exercise types, at least in the short term and in response to a single exercise bout. Certainty in all outcomes was low or very low, due to factors including risk of bias, lack of non-exercise controls, inconsistency, imprecision and small-study effects.
This investigation was prospectively registered on the Open Science Framework Registry ( https://osf.io/6f8dz ) and the full protocol underwent peer review prior to conducting the investigation.
循环生物标志物常用于研究急性运动对骨骼的反应，但由于研究设计、质量、所选生物标志物以及运动和参与者特征等因素的异质性，使得难以综合和评估现有证据。
本研究旨在采用系统评价和荟萃分析方法，定量评估急性运动对骨生物标志物的影响，并探讨潜在的调节因素，如参与者、运动和设计特征。
根据首选报告项目的系统评价和荟萃分析方案（PRISMA-P）指南设计方案，并前瞻性发表。根据预先确定的纳入标准，对 7 个数据库进行了系统搜索。采用贝叶斯三级层次荟萃分析模型，探讨急性运动对骨生物标志物的主要影响，以及潜在的调节因素。根据三个指标来解释模型化的效应大小，分别是（1）急性运动对骨生物标志物的影响证据（通过可信区间[CrI]是否包含零来确定）；（b）该影响的大小（分别使用 0.01、0.2、0.5 和 0.8 的阈值来描述非常小、小、中和大的效应大小）；（c）估计效应的确定性（使用 GRADE 框架定义）。
综合所有设计和分类的结果表明，急性运动增加了骨吸收（ES 0.10，95%CrI 0.00-0.20）和形成（ES 0.05，95%CrI 0.01-0.08）标志物，但效应非常小且高度可变。此外，调节分析揭示了这种变异性的部分来源，并表明运动类型和冲击负荷影响骨吸收反应。循环运动后，I 型胶原 C 端肽（CTX-1）的中等程度增加（ES 0.65，95%CrI 0.20-0.99），持续时间更长和更多的工作量导致 CTX-1 的增加更大。CTX-1 反应在运动后 15 分钟和 2 小时内达到峰值。其他运动类型不会影响 CTX-1。所有骨形成标志物的变化都非常小且短暂，运动停止后 15 分钟内，非常小的增加就恢复到基线水平。在研究的所有调节类别中，没有发现任何骨形成标志物的主要趋势。大多数结果的证据确定性被认为是低或非常低。
急性长时间骑自行车对骨吸收标志物 CTX-1 的强烈影响，以及任何生物标志物对阻力或高冲击运动类型均无反应，表明这些生物标志物可能更适用于研究运动的潜在溶骨性方面，并提出了关于其是否适合研究不同运动类型的成骨潜力的问题，至少在短期内和单次运动后是这样。由于存在偏倚风险、缺乏非运动对照、不一致性、不精确性和小样本效应等因素，所有结果的确定性都较低或非常低。
本研究在开放科学框架登记处（https://osf.io/6f8dz）进行了前瞻性登记，并在进行研究之前对完整方案进行了同行评审。
