Post-meal Exercise and Glycemic Control in Aging

描述（申请人的描述）：葡萄糖耐量随着年龄的增长而逐渐下降，代谢弹性的这种下降主要归因于年龄的次要因素，如身体成分的变化和低水平的体力活动。胰岛素分泌不足也是一个重要因素;然而，由于衰老和废用相关胰岛素抵抗的细胞补偿受损，可能确实会加速老年人发生挑战后高血糖症和随后的2型糖尿病和心血管疾病的风险。本提案的目的是研究不同运动方案对2型糖尿病高危老年人餐后和24小时血糖控制（使用连续血糖监测系统（CGMS）测量）的影响程度。具体目标是：1）比较传统练习的短期效果 条件包括在较低强度（约3.0 MET）下持续步行45分钟， 上午（TEM），下午（TEA）进行相同的条件，以改善葡萄糖耐量受损（IGT）的不活动老年人的餐后和24小时血糖控制; 2a）比较新的“吃和动”运动条件的短期效果[EM;步行15分钟（约3.0 MET）在3次标准餐后30分钟进行]，TEM和TEA对这些老年人血糖控制的改善;和2b）确定性别和腹部脂肪对这些老年男性和女性餐后运动相关的餐后和24小时血糖控制改善的影响。虽然餐后运动模式已被用作妊娠糖尿病的有效策略，但其在细胞功能受损的老年人群中的潜力尚未研究。较短但更频繁的低强度运动的临床相关性很大，因为老年人更有可能定期从事这种类型的体力活动。考虑到老年人高血糖症带来的额外疾病负担，以及慢性病预防的公认价值，设计最需要的人群中令人愉快和有效的运动计划对公共卫生有巨大的好处。公共卫生相关性：餐后高血糖可能是减缓糖耐量受损向2型糖尿病和心血管疾病进展的限速因素。餐后运动可能是补充内源性胰岛素作用的有效策略，可改善老年人的餐后和24小时血糖控制。较短但更频繁的低强度运动的临床相关性很大，因为老年人更有可能定期从事这种类型的体力活动。考虑到老年人高血糖症带来的额外疾病负担，以及慢性病预防的公认价值，设计最需要的人群中令人愉快和有效的运动计划对公共卫生有巨大的好处。

DESCRIPTION (applicant's description): Glucose tolerance declines progressively with aging, and this decline in metabolic resiliency can be attributed primarily to factors secondary to aging, such as changes in body composition and low levels of physical activity. Insufficient insulin secretion is also an important contributor; however, as impaired ¿-cell compensation to aging- and disuse-related insulin resistance may indeed accelerate the risk of developing post-challenge hyperglycemia and consequent type 2 diabetes and cardiovascular disease in older age. The purpose of this proposal is to examine the extent to which different exercise protocols impact post-prandial and 24-h glycemic control (measured using a continuous glucose monitoring system; CGMS) in older people at risk for type 2 diabetes. Specific aims are: 1) To compare the short-term effectiveness of a traditional exercise condition involving 45 min of sustained walking at lower intensity (~3.0 METs) performed in the morning (TEM), with the same condition performed in the afternoon (TEA) on improvements in postprandial and 24-h glycemic control in inactive older people with impaired glucose tolerance (IGT); 2a) To compare the short-term effectiveness of a novel "Eat and Move" exercise condition [EM; 15 min of walking (~3.0 METs) performed 30 min after each of 3 standard meals] with TEM and TEA on improvements in glycemic control in these same older people; and 2b) To determine the influence of sex and of abdominal fat on post-meal exercise-related improvements in post-prandial and 24-h glycemic control in these older men and women. While a post-meal exercise paradigm has been used as an effective strategy for gestational diabetes, its potential among older populations with compromised ¿-cell function has not been studied. The clinical relevance of shorter, but more frequent, bouts of lower-intensity exercise is substantial as older people are far more likely to engage in that type of physical activity on a regular basis. Given the excess disease burden associated with hyperglycemia in older age, and the recognized value of chronic disease prevention, there are enormous public health benefits to designing exercise programs that are enjoyable and effective within the populations needing them the most. PUBLIC HEALTH RELEVANCE: Post-prandial hyperglycemia may represent the rate-limiting factor in slowing the progression from impaired glucose tolerance toward frank type 2 diabetes and cardiovascular disease. Post-meal exercise may be an effective strategy for supplementing endogenous insulin action for improved post-prandial and 24-h glycemic control in older age. The clinical relevance of shorter, but more frequent, bouts of lower-intensity exercise is substantial as older people are far more likely to engage in that type of physical activity on a regular basis. Given the excess disease burden associated with hyperglycemia in older age, and the recognized value of chronic disease prevention, there are enormous public health benefits to designing exercise programs that are enjoyable and effective within the populations needing them the most.