Glycemic Load and Resistance Training on Endothelial Function and Inflammation

描述(由申请人提供)：该项目是由迫切的公共卫生需求推动的，即寻找最佳的营养和运动预防策略，以减少年轻人未来患心血管疾病和2型糖尿病的风险。本项目旨在研究单独使用低血糖负荷饮食以及与耐力训练相结合来改善内皮功能障碍、单核细胞炎症和24小时血糖变化的效果。将160名肥胖青年随机分为4组，每组12周：1)对照组高血糖负荷饮食；2)低血糖负荷饮食；3)高血糖负荷饮食+抗阻训练；或4)低血糖负荷饮食+抗阻训练。其目的是确定：1)与标准的高血糖负荷西化饮食相比，低血糖饮食是否可以改善内皮功能、单核细胞炎症和24小时血糖变化；2)低血糖饮食+RT与低血糖饮食具有相加作用，可以改善内皮功能、单核细胞炎症和24小时血糖变化。相关变量包括肱动脉血流介导的扩张(FMD)的内皮功能、流式细胞仪和PCR/蛋白质分析的单核细胞表型、24小时连续血糖监测系统、频繁采样的静脉葡萄糖耐量试验的胰岛素敏感性、DEXA的全身成分、MRI的内脏和肝脏脂肪分数以及对高血糖指数餐的急性反应。这些假设是，低血糖负荷饮食将改善上述关键的心血管风险相关依赖变量，并且增加阻力训练将产生相加效应。该项目将首次比较低血糖负荷饮食和/或抵抗力训练对内皮功能、单核细胞炎症和24小时血糖变化的单独和联合影响。如果这些假设得到支持，新的治疗方案将可用于改善血管功能障碍、慢性炎症和胰岛素抵抗的初级预防，包括那些替代疗法可能效果较差的年轻人。 公共卫生相关性：将首次在肥胖的年轻男性和女性中进行使用低血糖负荷饮食和/或抵抗力训练的随机对照试验。这项有效性试验应该对目前肥胖的数千万美国人具有重大的公共健康影响，他们的血管功能、慢性炎症状态和胰岛素敏感性不是最理想的，因此为新的预防健康策略提供了洞察力。此外，由于每个患者依从性问题的个性化特殊性，处方的治疗方法需要很大；目前的提议可能会增加治疗的范围。

DESCRIPTION (provided by applicant): This project is prompted by the urgent public health need to find optimal nutrition and exercise prevention strategies to reduce future cardiovascular disease and type 2 diabetes risk in young adults. This project aims to investigate the efficacy of a low-glycemic load diet both alone, and in combination with resistance training, to ameliorate endothelial dysfunction, monocyte inflammation and 24-hr glycemic variations. 160 obese young adults will be randomly assigned to 1 of 4 groups for 12 weeks: 1) a control high-glycemic load diet; 2) a low- glycemic load diet; 3) a high-glycemic load diet + resistance training; or 4) low-glycemic load diet + resistance training. The aims are to determine if: 1) a low-GL diet improves endothelial function, monocyte inflammation and 24-hr glycemic variations compared to a standard high-glycemic load, Westernized diet and 2) a low-GL diet + RT has an additive effect with low-GL diet to improve endothelial function, monocyte inflammation and 24-hr glycemic variations. Dependent variables include endothelial function by brachial artery flow-mediated dilation (FMD), monocyte phenotyping by flow cytometry and PCR/protein analysis, 24-hr continuous glucose monitoring systems, insulin sensitivity by frequently sampled intravenous glucose tolerance test, whole body composition by DEXA, visceral and hepatic fat fraction by MRI, and acute responses to a high-glycemic index meal. The hypotheses are that a low-glycemic load diet will improve the above key cardiovascular risk related dependent variables and that the addition of resistance training will induce additive effects. This project will, for the first time, compare the isolated and combined effects of a low-glycemic load diet and/or resistance training on endothelial function, monocyte inflammation and 24-hr glycemic variations. If the hypotheses are upheld, new therapeutic options will become available to improve primary prevention of vascular dysfunction, chronic inflammation and insulin resistance, including in those young adults where alternative therapies may be less effective. PUBLIC HEALTH RELEVANCE: For the first time, a randomized controlled trial using a low glycemic-load diet and/or resistance training will be carried out in obese young men and women. This efficacy trial should have major public health implications to the tens of millions of Americans currently obese, presenting with less than optimal vascular function, chronic inflammatory status and insulin sensitivity, thus providing insight into novel preventive health strategies. Furthermore, due to individualized specificity of compliance issues for each patient, the arsenal of therapies for prescription needs to be large; the current proposal will potentially increase the range of therapies.