ABOLISHING INCREASES IN INSULIN SENSITIVITY IN POSTMENOPAUSAL WOMEN

消除绝经后女性胰岛素敏感性的增加

• 批准号: 6303488
• 负责人: KATARINA T BORER
• 金额: $ 0.02万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-12-01 至 2001-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6303488
• 关键词: adipose tissue; aging; clinical research; coronary disorder; disease /disorder proneness /risk; exercise; hormone biosynthesis; human subject; hypertension; insulin sensitivity /resistance; noninsulin dependent diabetes mellitus; obesity; postmenopause; women's health

Inactivity and excessive and inappropriate caloric intake stimulate development of visceral obesity that is associated with increased risks of type 2 (non-insulin-dependent) diabetes, hypertension, and coronary heart disease (CHD). Both exercise and dietary restriction have been successfully used as a means of body fat loss. In addition, exercise, with or without fat loss, can reduce risks of diabetes, hypertension, and CHD but its effects have not been consistent. In particular, there is little consensus regarding the effects of exercise intensity on either insulin sensitivity, body fat loss, or risks of hypertension and CHD. Our premise is that if exercise is to be used effectively to prevent or reduce different health risks or to be used as a tool in mechanistic analyses of hormone action, a better understanding of dose-dependent effects of exercise intensity is needed. Our pilot study, initiated two years ago, tested the hypothesis that exercise training at high walking intensities could increase basal pulsatile growth hormone (GH) secretion. The preliminary results supported this hypothesis, but in addition revealed that increases in training intensity attenuate increases in insulin sensitivity (assessed with an indirect measure of insulin sensitivity) that usually accompany exercise training. The goals of the present study are to (1) replicate in a larger group of 18 subjects the observed attenuation of insulin sensitivity at high training intensities with the more specific test of insulin sensitivity, Bergman's frequently sampled intravenous glucose tolerance test (FSIVGTT); (2) determine whether the effect of exercise intensity on insulin sensitivity is a consequence of, or independent of, changes in body fat mass and distribution; (3) replicate in a larger group of 18 subjects the observed increases in pulsatile GH secretion between 15 and 30 weeks of exercise training at high training intensities, and (4) collect some preliminary information on the effects of exercise intensity on plasma lipids (HDL-cholesterol , LDL-cholesterol, and triglycerides) which also constitute a risk of developing CHD.

缺乏活动以及过多和不适当的热量摄入会刺激内脏肥胖的发展，而内脏肥胖又与 2 型（非胰岛素依赖型）糖尿病、高血压和冠心病 (CHD) 的风险增加相关。 运动和饮食限制都已被成功地用作减少身体脂肪的手段。 此外，运动，无论是否减少脂肪，都可以降低患糖尿病、高血压和冠心病的风险，但其效果并不一致。特别是，关于运动强度对胰岛素敏感性、体脂减少或高血压和冠心病风险的影响，几乎没有达成共识。我们的前提是，如果要有效地利用运动来预防或减少不同的健康风险，或者将运动用作激素作用机制分析的工具，则需要更好地了解运动强度的剂量依赖性效应。 我们两年前启动的试点研究测试了这样的假设：高步行强度的运动训练可以增加基础脉动生长激素 (GH) 的分泌。初步结果支持了这一假设，但此外还表明，训练强度的增加会减弱通常伴随运动训练的胰岛素敏感性的增加（通过胰岛素敏感性的间接测量进行评估）。本研究的目标是（1）在更大的 18 名受试者组中复制观察到的高训练强度下胰岛素敏感性的衰减，并通过更具体的胰岛素敏感性测试，伯格曼频繁采样的静脉葡萄糖耐量测试（FSIVGTT）； (2) 确定运动强度对胰岛素敏感性的影响是否是身体脂肪量和分布变化的结果，还是独立于其变化； (3) 在 18 名受试者组成的较大组中复制观察到的高训练强度运动训练 15 至 30 周期间脉动 GH 分泌的增加，以及 (4) 收集一些关于运动强度对血脂（高密度脂蛋白胆固醇、低密度脂蛋白胆固醇和甘油三酯）影响的初步信息，这也构成了患冠心病的风险。