Shephard Roy J, Johnson Nathan
Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada,
Eur J Appl Physiol. 2015 Jan;115(1):1-46. doi: 10.1007/s00421-014-3031-6. Epub 2014 Nov 4.
To review the responses of the liver to acute and chronic physical activity and to summarize relationships between physical activity and liver health.
A systematic search of HealthStar/Ovid from 1975 through June of 2013, supplemented by articles from other sources.
351 of 8,010 articles identified by HealthStar/Ovid were supplemented by 92 other papers; after focussing, the review was reduced to 435 citations. Prolonged acute exercise reduces hepatic blood flow, stimulating hepatic glycogenolysis, gluconeogenesis and synthesis of some proteins; however, lipid metabolism shows little change. Glutathione depletion suggests oxidative stress. Enzymes affecting carbohydrate metabolism are up-regulated, and lipogenic enzymes are down-regulated. The main triggers are humoral, but hepatic afferent nerves, cytokines, reactive oxygen species, and changes in hepatic blood flow may all play some role. Regular aerobic exercise training improves blood glucose control during exercise by increasing glycogen stores and up-regulating enzymes involved in gluconeogenesis and carbohydrate metabolism. Resistance to oxidant stress is generally increased by training. Lipogenic enzymes are down-regulated, and lipid metabolism is augmented. Modulations of insulin, insulin-like growth factor, glucagon and interleukin-6 may trigger the adaptive responses to training. Cross-sectional and longitudinal studies show that regular exercise can reduce hepatic fat, but the effect on circulating aminotransferases is unclear and the modality and dose of physical activity optimizing health benefits need clarification.
Regular moderate physical activity enhances liver health. Adverse functional changes can develop if habitual activity is inadequate, and extremely prolonged competitive exercise may also be harmful, particularly under harsh environmental conditions.
回顾肝脏对急性和慢性体育活动的反应，并总结体育活动与肝脏健康之间的关系。
对1975年至2013年6月的HealthStar/Ovid进行系统检索，并辅以其他来源的文章。
HealthStar/Ovid识别出的8010篇文章中的351篇由其他92篇论文补充；经过筛选，综述减少至435条引用文献。长时间的急性运动可减少肝血流量，刺激肝糖原分解、糖异生及某些蛋白质的合成；然而，脂质代谢变化不大。谷胱甘肽耗竭提示氧化应激。影响碳水化合物代谢的酶上调，脂肪生成酶下调。主要触发因素是体液因素，但肝传入神经、细胞因子、活性氧及肝血流量变化可能均起一定作用。定期进行有氧运动训练可通过增加糖原储备及上调参与糖异生和碳水化合物代谢的酶来改善运动期间的血糖控制。训练通常可增强抗氧化应激能力。脂肪生成酶下调，脂质代谢增强。胰岛素、胰岛素样生长因子、胰高血糖素及白细胞介素-6的调节可能触发对训练的适应性反应。横断面和纵向研究表明，规律运动可减少肝脏脂肪，但对循环中的转氨酶的影响尚不清楚，且优化健康益处的体育活动方式和剂量需要进一步明确。
定期进行适度体育活动可增强肝脏健康。如果习惯性活动不足，可能会出现不良功能变化，而极端长时间的竞技运动也可能有害，尤其是在恶劣环境条件下。
