Department of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark , Odense , Denmark.
The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen , Copenhagen , Denmark.
Am J Physiol Endocrinol Metab. 2018 Nov 1;315(5):E872-E884. doi: 10.1152/ajpendo.00161.2018. Epub 2018 Jul 17.
This study compared the effects of moderate-intensity endurance training and high-intensity interval training on fiber type-specific subcellular volumetric content and morphology of lipid droplets and mitochondria in skeletal muscles of type 2 diabetic patients. Sixteen sedentary type 2 diabetic patients (57 ± 7 yr old) were randomized to complete 11 wk of either 40-min cycling at 50% peak workload (Endurance, n = 8) or 10 1-min cycling intervals at 95% peak workload separated by 1 min of recovery (High-Intensity Interval, n = 8), three times per week. Assessments for cardiorespiratory fitness, body composition, glycemic control, together with muscle biopsies were performed before and after the intervention. Morphometric analyses of lipid droplets and mitochondria were conducted in the subcellular fractions of biopsied muscle fibers using quantitative electron microscopy. The training intervention increased cardiorespiratory fitness, lowered fat mass, and improved nonfasting glycemic control ( P < 0.05), with no difference between training modalities. In the subsarcolemmal space, training decreased lipid droplet volume ( P = 0.003), and high-intensity interval, but not endurance, training reduced the size of lipid droplets, specifically in type 2 fibers ( P < 0.001). No training-induced change in intermyofibrillar lipid droplets was observed in both fiber types. Subsarcolemmal mitochondrial volume was increased by high-intensity interval ( P = 0.02), but not endurance, training ( P = 0.79). Along with improvement in glycemic control, low-volume high-intensity interval training is an alternative time-saving training modality that affects subcellular morphology and volumetric content of lipid droplets in skeletal muscle of type 2 diabetic patients.
这项研究比较了中等强度耐力训练和高强度间歇训练对 2 型糖尿病患者骨骼肌纤维类型特异性亚细胞脂滴和线粒体容积含量和形态的影响。16 名久坐的 2 型糖尿病患者（57±7 岁）随机分为两组，分别完成 11 周的 40 分钟 50%峰值负荷骑行（耐力组，n=8）或 10 个 95%峰值负荷的 1 分钟骑行间隔，间隔 1 分钟恢复（高强度间歇组，n=8），每周 3 次。在干预前后进行心肺功能适应性、身体成分、血糖控制评估，同时进行肌肉活检。使用定量电子显微镜对活检肌肉纤维的亚细胞部分进行脂滴和线粒体的形态计量分析。训练干预提高了心肺功能适应性，降低了脂肪量，改善了非空腹血糖控制（P<0.05），但两种训练方式之间没有差异。在肌小节下空间，训练减少了脂滴体积（P=0.003），高强度间歇训练，而不是耐力训练，减少了脂滴的大小，特别是在 2 型纤维中（P<0.001）。两种纤维类型的肌间脂滴均未观察到训练引起的变化。高强度间歇训练增加了肌小节间线粒体体积（P=0.02），但耐力训练没有（P=0.79）。随着血糖控制的改善，低容量高强度间歇训练是一种节省时间的替代训练方式，可影响 2 型糖尿病患者骨骼肌中亚细胞脂滴的形态和容积含量。
