Post-meal Exercise and Glycemic Control in Aging

描述（申请人描述）：葡萄糖耐量随着年龄的增长而逐渐下降，代谢弹性的下降主要归因于衰老的继发因素，如身体成分的变化和低水平的身体活动。胰岛素分泌不足也是一个重要因素；然而，由于细胞对衰老和废用相关的胰岛素抵抗的补偿受损，确实可能加速老年人发生挑战后高血糖和随后的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型糖尿病风险老年人餐后和24小时血糖控制（使用连续血糖监测系统测量；CGMS）的影响程度。具体目标是：1)比较传统练习的短期效果

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.