PDF(Pubmed)
Abstract：
BACKGROUND: Circulating miRNAs (c-miR) have been shown to be potential biomarkers in sarcopenia, but the miRNAs response to aerobic exercise in older people remains inconclusive. We sought to examine the exercise benefits on physical fitness and miRNAs, and to explore the mediating effect of miRNAs on training-induced fitness changes.
METHODS: This controlled trial recruited 58 community-dwelling older adults and randomized them into exercise group (EX) and control group (CON). EX received 8-week supervised moderate intensity cycling training 3x/week. C-miR expression (c-miR-21, c-miR-126, c-miR-146a, c-miR-222), physical fitness (body composition, cardiorespiratory fitness, muscular fitness) and physical activity level (PAL, measured as in daily step counts) were evaluated at baseline, post-training, and post-16-week follow-up. The mediating effect of miRNA expression onto exercise-induced physical fitness change was determined by causal mediation analysis (CMA).
RESULTS: Exercise significantly improved body fat and cardiorespiratory fitness in older people while maintaining muscle mass and strength, and augmented expression of c-miR-126, c-miR-146a, and c-miR-222 for up to 16 weeks post-training. Notably, older people in EX had substantially higher daily step counts than CON throughout the study even after the active training period. However, CMA revealed no significant indirect effect but a potential mediating effect of c-miR-21, but not the rest, onto the body composition, cardiorespiratory fitness, and lower limb strength.
CONCLUSIONS: An eight-week supervised MICT program promoted a higher level of physical activity up to 16 weeks post-training, which induces better cardiorespiratory fitness and resists decline in muscular measures. C-miRNA, especially c-miR-21, potentially mediates the training effect upon fitness.
METHODS: This controlled trial recruited 58 community-dwelling older adults and randomized them into exercise group (EX) and control group (CON). EX received 8-week supervised moderate intensity cycling training 3x/week. C-miR expression (c-miR-21, c-miR-126, c-miR-146a, c-miR-222), physical fitness (body composition, cardiorespiratory fitness, muscular fitness) and physical activity level (PAL, measured as in daily step counts) were evaluated at baseline, post-training, and post-16-week follow-up. The mediating effect of miRNA expression onto exercise-induced physical fitness change was determined by causal mediation analysis (CMA).
RESULTS: Exercise significantly improved body fat and cardiorespiratory fitness in older people while maintaining muscle mass and strength, and augmented expression of c-miR-126, c-miR-146a, and c-miR-222 for up to 16 weeks post-training. Notably, older people in EX had substantially higher daily step counts than CON throughout the study even after the active training period. However, CMA revealed no significant indirect effect but a potential mediating effect of c-miR-21, but not the rest, onto the body composition, cardiorespiratory fitness, and lower limb strength.
CONCLUSIONS: An eight-week supervised MICT program promoted a higher level of physical activity up to 16 weeks post-training, which induces better cardiorespiratory fitness and resists decline in muscular measures. C-miRNA, especially c-miR-21, potentially mediates the training effect upon fitness.
摘要：
背景：循环miRNA（c-miR）已被证明是肌肉减少症的潜在生物标志物，但老年人对有氧运动的miRNAs反应仍无定论。我们试图研究运动对身体健康和miRNAs的益处，并探讨miRNAs在训练引起的适应性变化中的中介作用。
方法：这项对照试验招募了58名社区居住的老年人，并将他们随机分为运动组（EX）和对照组（CON）。EX接受了为期8周的有监督的中等强度自行车训练，每周3次。C-miR表达（c-miR-21，c-miR-126，c-miR-146a，c-miR-222），身体健康(身体成分，心肺健康，肌肉健康)和身体活动水平(PAL，以每日步数测量)在基线评估，培训后,以及16周后的随访。通过因果中介分析（CMA）确定miRNA表达对运动引起的身体健康变化的中介作用。
结果：运动显著改善了老年人的体脂和心肺健康，同时保持了肌肉质量和力量，和c-miR-126，c-miR-146a的表达增强，和c-miR-222训练后长达16周。值得注意的是,在整个研究过程中,即使在积极的训练期后,EX组的老年人的每日步数也明显高于CON.然而,CMA显示c-miR-21没有显著的间接作用，但潜在的介导作用，身体成分上，心肺健康，和下肢力量。
结论：一项为期八周的MICT计划在训练后16周内促进了更高水平的体育锻炼，这会导致更好的心肺健康，并抵抗肌肉措施的下降。C-miRNA,特别是c-miR-21，可能介导健身训练效果。
方法：这项对照试验招募了58名社区居住的老年人，并将他们随机分为运动组（EX）和对照组（CON）。EX接受了为期8周的有监督的中等强度自行车训练，每周3次。C-miR表达（c-miR-21，c-miR-126，c-miR-146a，c-miR-222），身体健康(身体成分，心肺健康，肌肉健康)和身体活动水平(PAL，以每日步数测量)在基线评估，培训后,以及16周后的随访。通过因果中介分析（CMA）确定miRNA表达对运动引起的身体健康变化的中介作用。
结果：运动显著改善了老年人的体脂和心肺健康，同时保持了肌肉质量和力量，和c-miR-126，c-miR-146a的表达增强，和c-miR-222训练后长达16周。值得注意的是,在整个研究过程中,即使在积极的训练期后,EX组的老年人的每日步数也明显高于CON.然而,CMA显示c-miR-21没有显著的间接作用，但潜在的介导作用，身体成分上，心肺健康，和下肢力量。
结论：一项为期八周的MICT计划在训练后16周内促进了更高水平的体育锻炼，这会导致更好的心肺健康，并抵抗肌肉措施的下降。C-miRNA,特别是c-miR-21，可能介导健身训练效果。
