Institute for Sport, Exercise and Active Living, School of Sport and Exercise Science, Victoria University, Melbourne, Australia.
Osteoporos Int. 2011 May;22(5):1621-6. doi: 10.1007/s00198-010-1370-7. Epub 2010 Aug 24.
The purpose of this study was to examine if the reduction in glucose post-exercise is mediated by undercarboxylated osteocalcin (unOC). Obese men were randomly assigned to do aerobic or power exercises. The change in unOC levels was correlated with the change in glucose levels post-exercise. The reduction in glucose post-acute exercise may be partly related to increased unOC.
Osteocalcin (OC) in its undercarboxylated (unOC) form may contribute to the regulation of glucose homeostasis. As exercise reduces serum glucose and improves insulin sensitivity in obese individuals and individuals with type 2 diabetes (T2DM), we hypothesised that this benefit was partly mediated by unOC.
Twenty-eight middle-aged (52.4 ± 1.2 years, mean ± SEM), obese (BMI = 32.1 ± 0.9 kg m(-2)) men were randomly assigned to do either 45 min of aerobic (cycling at 75% of VO(2peak)) or power (leg press at 75% of one repetition maximum plus jumping sequence) exercises. Blood samples were taken at baseline and up to 2 h post-exercise.
At baseline, unOC was negatively correlated with glucose levels (r = -0.53, p = 0.003) and glycosylated haemoglobin (HbA1c) (r = -0.37, p = 0.035). Both aerobic and power exercises reduced serum glucose (from 7.4 ± 1.2 to 5.1 ± 0.5 mmol L(-1), p = 0.01 and 8.5 ± 1.2 to 6.0 ± 0.6 mmol L(-1), p = 0.01, respectively). Aerobic exercise significantly increased OC, unOC and high-molecular-weight adiponectin, while power exercise had a limited effect on OC and unOC. Overall, those with higher baseline glucose and HbA1c had greater reductions in glucose levels after exercise (r = -0.46, p = 0.013 and r = -0.43, p = 0.019, respectively). In a sub-group of obese people with T2DM, the percentage change in unOC levels was correlated with the percentage change in glucose levels post-exercise (r = -0.51, p = 0.038).
This study reports that the reduction in serum glucose post-acute exercise (especially aerobic exercise) may be partly related to increased unOC.
本研究旨在探讨运动后葡萄糖降低是否与未羧化骨钙素（unOC）有关。研究将肥胖男性随机分为进行有氧运动或力量训练。unOC 水平的变化与运动后葡萄糖水平的变化相关。急性运动后葡萄糖的降低可能部分与 unOC 增加有关。
未羧化（unOC）形式的骨钙素（OC）可能有助于调节血糖稳态。运动可降低肥胖个体和 2 型糖尿病（T2DM）患者的血清葡萄糖并提高胰岛素敏感性，因此我们假设这种益处部分是由 unOC 介导的。
28 名中年（52.4±1.2 岁，平均值±SEM）肥胖男性（BMI=32.1±0.9kgm(-2)）被随机分为进行 45 分钟有氧运动（以 75%最大摄氧量进行自行车运动）或力量训练（以 75%一次重复最大力量加跳跃序列进行腿部按压）。在基线和运动后 2 小时内采集血液样本。
在基线时，unOC 与葡萄糖水平（r=-0.53，p=0.003）和糖化血红蛋白（HbA1c）（r=-0.37，p=0.035）呈负相关。有氧运动和力量训练均降低了血清葡萄糖（从 7.4±1.2mmolL(-1)降至 5.1±0.5mmolL(-1)，p=0.01 和从 8.5±1.2mmolL(-1)降至 6.0±0.6mmolL(-1)，p=0.01）。有氧运动显著增加了 OC、unOC 和高分子量脂联素，而力量训练对 OC 和 unOC 的影响有限。总体而言，基线时血糖和 HbA1c 较高的人，运动后血糖降低幅度更大（r=-0.46，p=0.013 和 r=-0.43，p=0.019）。在患有 2 型糖尿病的肥胖人群亚组中，unOC 水平的变化百分比与运动后葡萄糖水平的变化百分比相关（r=-0.51，p=0.038）。
本研究表明，急性运动后血清葡萄糖的降低（尤其是有氧运动）可能部分与 unOC 增加有关。
