中等强度持续运动和高强度间歇运动对小鼠肥胖性肌萎缩的干预作用

Effects of moderate-intensity continuous training and high-intensity interval training on obesity-related muscle atrophy in mice

背景:肥胖已成为全球范围内的健康问题之一,伴随而来的是肥胖性肌萎缩等相关并发症。虽然运动已被报道可以改善多种肥胖相关疾病,但是其中鲜有关于运动模式的研究。目的:在相同运动距离的前提下,比较中等强度持续运动(moderate-intensity continuous training,MICT)与高强度间歇运动(high-intensity interval training,HIIT)两种运动模式对小鼠肥胖性肌萎缩的改善作用,为肥胖性肌萎缩的运动干预疗法的选择提供科学依据。方法:将72只C57BL/6雄性小鼠分为普通饮食组、普通饮食+MICT组,普通饮食+HIIT组、高脂饮食组、高脂饮食+MICT组、高脂饮食+HIIT组(每组12只),通过检测小鼠腓肠肌质量、腓肠肌指数、腓肠肌肌纤维横截面积、腓肠肌脂质沉积以及腓肠肌中肌萎缩标志基因Murf-1与Atrogin-1的表达量来评估8周不同运动模式的跑台训练对于长期高脂饮食引起的肌萎缩的改善作用。结果与结论:(1)与高脂饮食组相比,MICT和HIIT均改善了腓肠肌指数(MICT+18.8%vs.HIIT+17.6%,两种运动模式无显著差异)、肌纤维萎缩(MICT+15.5%vs.HIIT+13.7%,两种运动模式无显著差异)和腓肠肌脂质沉积(MICT-19.8%vs.HIIT-17.1%,两种运动模式无显著差异)。(2)在基因水平上,与高脂饮食组相比,MICT和HIIT运动模式均能显著下调Murf-1(MICT-62.4%vs.HIIT-52.6%,MICT显著优于HIIT,P<0.01)和Atrogin-1(MICT-43.3%vs.HIIT-29.8%,MICT显著优于HIIT,P<0.01)。(3)基于运动模式难度与舒适性的考量以及基因水平上的证据显示,MICT模式更适合用于肥胖性肌萎缩的运动干预。

BACKGROUND:Obesity has become a global health issue,often accompanied by complications including obesity-related muscle atrophy.While exercise has been reported to improve various obesity-related diseases,there is limited research focusing on exercise modes.OBJECTIVE:To compare the effects of moderate-intensity continuous training(MICT)and high-intensity interval training(HIIT)on obesity-related muscle atrophy in mice under the premise of the same exercise distance,providing a scientific basis for exercise interventions for obesity-related muscle atrophy.METHODS:Seventy-two male C57BL/6 mice were divided into six groups(n=12 per group):standard chow diet,standard chow diet+MICT,standard chow diet+HIIT,high-fat diet,high-fat diet+MICT,and high-fat diet+HIIT.The study evaluated the effects of 8-week treadmill training with different exercise modes on long-term high-fat diet-induced muscle atrophy by detecting muscle mass,muscle index,muscle fiber cross-sectional area,muscle lipid deposition,and the expression of muscle atrophy marker genes Murf-1 and Atrogin-1 in the gastrocnemius muscle of mice exposed to long-term high-fat diet.RESULTS AND CONCLUSION:Compared to the high-fat diet group,both MICT and HIIT improved the decrease in gastrocnemius muscle index(MICT+18.8%vs.HIIT+17.6%,not significant between the two modes),muscle fiber atrophy(MICT+15.5%vs.HIIT+13.7%,not significant between the two modes),and muscle lipid deposition(MICT-19.8%vs.HIIT-17.1%,not significant between the two modes).At the gene level,compared with the high-fat diet group,both MICT and HIIT could significantly down-regulate the expression of Murf-1(MICT-62.4%vs.HIIT-52.6%,the down-regulation caused by MICT was significantly greater than that by HIIT;P<0.01)and Atrogin-1(MICT-43.3%vs.HIIT-29.8%,the down-regulation caused by MICT was significantly greater than that by HIIT;P<0.01).Based on exercise mode comfort and genetic evidence,MICT mode might be more suitable for exercise interventions in obesity-related muscle atrophy.