Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio;
Am J Physiol Endocrinol Metab. 2013 Nov 15;305(10):E1248-54. doi: 10.1152/ajpendo.00260.2013. Epub 2013 Sep 17.
Although some studies suggest that a linear dose-response relationship exists between exercise and insulin sensitivity, the exercise dose required to enhance pancreatic β-cell function is unknown. Thirty-five older obese adults with prediabetes underwent a progressive 12-wk supervised exercise intervention (5 days/wk for 60 min at ~85% HRmax). Insulin and C-peptide responses to an OGTT were used to define the first- and second-phase disposition index (DI; β-cell function = glucose-stimulated insulin secretion × clamp-derived insulin sensitivity). Maximum oxygen consumption (Vo2max) and body composition (dual-energy X-ray absorptiometry and computed tomography) were also measured before and after the intervention. Exercise dose was computed using Vo2/heart-rate derived linear regression equations. Subjects expended 474.5 ± 8.8 kcal/session (2,372.5 ± 44.1 kcal/wk) during the intervention and lost ~8% body weight. Exercise increased first- and second-phase DI (P < 0.05), and these changes in DI were linearly related to exercise dose (DIfirst phase: r = 0.54, P < 0.001; DIsecond phase: r = 0.56, P = 0.0005). Enhanced DI was also associated with increased Vo2max (DIfirst phase: r = 0.36, P = 0.04; DIsecond phase: r = 0.41, P < 0.02) but not lower body fat (DIfirst phase: r = -0.21, P = 0.25; DIsecond phase: r = -0.30, P = 0.10) after training. Low baseline DI predicted an increase in DI after the intervention (DIfirst phase: r = -0.37; DIsecond phase: r = -0.41, each P < 0.04). Thus, exercise training plus weight loss increased pancreatic β-cell function in a linear dose-response manner in adults with prediabetes. Our data suggest that higher exercise doses (i.e., >2,000 kcal/wk) are necessary to enhance β-cell function in adults with poor insulin secretion capacity.
虽然一些研究表明，运动与胰岛素敏感性之间存在线性剂量反应关系，但增强胰岛β细胞功能所需的运动剂量尚不清楚。35 名患有前驱糖尿病的老年肥胖成年人接受了为期 12 周的监督运动干预（每周 5 天，每次 60 分钟，约 85% HRmax）。口服葡萄糖耐量试验（OGTT）的胰岛素和 C 肽反应用于定义第一和第二相分布指数（DI；β细胞功能=葡萄糖刺激的胰岛素分泌×钳夹衍生的胰岛素敏感性）。在干预前后还测量了最大摄氧量（Vo2max）和身体成分（双能 X 射线吸收法和计算机断层扫描）。使用 Vo2/心率推导的线性回归方程计算运动剂量。研究对象在干预期间消耗了 474.5 ± 8.8 kcal/session（2,372.5 ± 44.1 kcal/wk），并减轻了约 8%的体重。运动增加了第一和第二相 DI（P < 0.05），并且这些 DI 的变化与运动剂量呈线性相关（第一相 DI：r = 0.54，P < 0.001；第二相 DI：r = 0.56，P = 0.0005）。增强的 DI 也与 Vo2max 的增加相关（第一相 DI：r = 0.36，P = 0.04；第二相 DI：r = 0.41，P < 0.02），但与体脂减少无关（第一相 DI：r = -0.21，P = 0.25；第二相 DI：r = -0.30，P = 0.10）。训练后。低基线 DI 预测干预后 DI 的增加（第一相 DI：r = -0.37；第二相 DI：r = -0.41，均 P < 0.04）。因此，运动训练加体重减轻以线性剂量反应方式增加了前驱糖尿病成年人的胰岛β细胞功能。我们的数据表明，需要更高的运动剂量（即>2,000 kcal/wk）才能增强胰岛素分泌能力差的成年人的β细胞功能。
