Venojärvi M, Puhke R, Hämäläinen H, Marniemi J, Rastas M, Rusko H, Nuutila P, Hänninen O, Aunola S
Department of Physiology, University of Kuopio, Kuopio, Finland.
Diabetes Obes Metab. 2005 Nov;7(6):745-54. doi: 10.1111/j.1463-1326.2004.00466.x.
The aim of this study was to investigate the role of skeletal muscle fibre type in the regulation of glucose metabolism in middle-aged obese subjects with impaired glucose tolerance (IGT) during a 2-year exercise and dietary intervention.
Muscle biopsies (musculus vastus lateralis) were taken from 22 subjects belonging to the intervention group of the Finnish Diabetes Prevention Study [1]. According to their myosin heavy chain (MHC) profile at the baseline, the subjects were divided into two groups: IGT(slow) (n=10) with a high proportion of MHC I isoforms and IGT(fast) (n=12) with a high proportion of MHC II isoforms in the vastus lateralis muscle. The intervention consisted of dietary counselling, strength and power training and/or aerobic exercise. The amount of exercise was the same in both groups; the exercise frequency was 5.1+/-2.7 h/week in the IGT(slow) and 5.1+/-2.8 h/week in the IGT(fast) group.
Fasting glucose (p<0.05), 2-h glucose (p<0.05), fasting insulin (p<0.05), haemoglobin A1c (HbA(1c)) (p<0.01) and insulin resistance (p<0.05) [homeostasis model assessment for insulin resistance (HOMA-IR)] decreased in the IGT(fast) group, whereas only the 2-h glucose and HbA(1c) concentrations decreased in the IGT(slow) group. The amount of the glycogen synthase kinase-3-alphabeta (GSK-3-alphabeta) decreased in the IGT(fast) group (p<0.05). Exercise training increased the lactate dehydrogenase (LDH) (p<0.01), LDH-1 (p<0.05) and citrate synthase (CS) (p<0.05) activities in the vastus lateralis muscle in the IGT(slow) group, but only the CS activity (p<0.05) in the IGT(fast) group.
The glucose metabolism improved both in the IGT(slow) and IGT(fast) group during the 2-year exercise and dietary intervention. The change was more prominent in the IGT(fast) group than in the IGT(slow) group, associated with the decrease of the GSK-alphabeta protein expression in skeletal muscle. The exercise training improved both glycolytic and oxidative capacity in the vastus lateralis muscle. The glycolytic capacity improved in the IGT(slow) group and the oxidative capacity in both groups.
本研究旨在调查骨骼肌纤维类型在糖耐量受损（IGT）的中年肥胖受试者为期2年的运动和饮食干预期间对葡萄糖代谢调节中的作用。
从芬兰糖尿病预防研究干预组的22名受试者身上采集外侧股四头肌肌肉活检样本[1]。根据基线时的肌球蛋白重链（MHC）谱，将受试者分为两组：外侧股四头肌中MHC I亚型比例高的IGT（慢）组（n = 10）和MHC II亚型比例高的IGT（快）组（n = 12）。干预包括饮食咨询、力量和功率训练及/或有氧运动。两组的运动量相同；IGT（慢）组的运动频率为5.1±2.7小时/周，IGT（快）组为5.1±2.8小时/周。
IGT（快）组的空腹血糖（p<0.05）、2小时血糖（p<0.05）、空腹胰岛素（p<0.05）、糖化血红蛋白（HbA1c）（p<0.01）和胰岛素抵抗（p<0.05）[胰岛素抵抗稳态模型评估（HOMA-IR）]降低，而IGT（慢）组仅2小时血糖和HbA1c浓度降低。IGT（快）组糖原合酶激酶-3αβ（GSK-3αβ）的量减少（p<0.05）。运动训练增加了IGT（慢）组外侧股四头肌中乳酸脱氢酶（LDH）（p<0.01）、LDH-1（p<0.05）和柠檬酸合酶（CS）（p<0.05）的活性，但IGT（快）组仅增加了CS活性（p<0.05）。
在为期2年的运动和饮食干预期间，IGT（慢）组和IGT（快）组的葡萄糖代谢均得到改善。IGT（快）组的变化比IGT（慢）组更显著，这与骨骼肌中GSKαβ蛋白表达的降低有关。运动训练改善了外侧股四头肌的糖酵解和氧化能力。IGT（慢）组的糖酵解能力得到改善，两组的氧化能力均得到改善。
