Bergfors M, Barnekow-Bergkvist M, Kalezic N, Lyskov E, Eriksson J W
Department for Studies in Biology and Environmental Sciences, Umeå University, Umeå, Sweden.
Acta Physiol Scand. 2005 Apr;183(4):345-56. doi: 10.1111/j.1365-201X.2005.01407.x.
To determine whether repetitive arm work, with a large component of static muscle contraction alters glucose metabolism and insulin sensitivity.
Euglycemic clamps (2 h) were started in ten healthy individuals 15 min after 37 min periods of: (1) repetitive arm work in a simulated occupational setting; (2) dynamic concentric exercise on a cycle ergometer at 60% of VO(2max) and (3) a resting regime as a control. During the experimental periods, blood samples were collected, blood pressure was measured repeatedly and electrocardiogram (ECG) was recorded continuously. During the clamps, euglycemia was maintained at 5 mmol l(-1) and insulin was infused at 56 mU m(-2) min(-1) for 120 min.
The insulin-mediated glucose disposal rate (M-value) for the steady-state period (60-120 min) of the clamp, tended to be lower following arm work than for both cycling and resting regimes. When dividing the steady-state period into 20-min intervals, the insulin sensitivity index (ISI) was significantly lower for arm work compared with the resting control situation between 60-80 min (P = 0.04) and 80-100 min (P = 0.01), respectively. Catecholamines increased significantly for arm work and cycling compared with resting regime. Data from heart rate variability (HRV) measurements indicated significant sympathetic activation during repetitive arm work.
The results indicate that repetitive arm work might acutely promote insulin resistance, whereas no such effect on insulin resistance was produced by dynamic concentric exercise.
确定包含大量静态肌肉收缩的重复性手臂工作是否会改变葡萄糖代谢和胰岛素敏感性。
对10名健康个体进行正常血糖钳夹试验（2小时），在以下37分钟时间段后的15分钟开始：（1）在模拟职业环境中进行重复性手臂工作；（2）在自行车测力计上以60%的最大摄氧量（VO₂max）进行动态向心运动；（3）以休息状态作为对照。在实验期间，采集血样，反复测量血压并连续记录心电图（ECG）。在钳夹期间，将正常血糖维持在5 mmol l⁻¹，并以56 mU m⁻² min⁻¹的速率输注胰岛素120分钟。
在钳夹的稳态期（60 - 120分钟），手臂工作后的胰岛素介导的葡萄糖处置率（M值）往往低于骑行和休息状态。当将稳态期分为20分钟间隔时，与休息对照状态相比，手臂工作在60 - 80分钟（P = 0.04）和80 - 100分钟（P = 0.01）时胰岛素敏感性指数（ISI）显著降低。与休息状态相比，手臂工作和骑行时儿茶酚胺显著增加。心率变异性（HRV）测量数据表明在重复性手臂工作期间存在显著的交感神经激活。
结果表明，重复性手臂工作可能会急性促进胰岛素抵抗，而动态向心运动对胰岛素抵抗没有这种影响。
