AMPLIFIed muscle mass in older cancer survivors enrolled in a diet-exercise program

我们建议将肌肉质量的测量添加到一个已经获得资助的项目中 格兰特。身体机能的快速下降通常发生在癌症诊断后， 尤其是在老年癌症幸存者中；然而，少数饮食和运动干预 已经被发现可以改善这些损失。肌肉质量的贡献及其在体内的变化 老年男性和女性的肌肉质量不佳，特别是那些癌症幸存者。 特征性的，部分原因是无法直接和准确地量化骨骼肌质量 以及依赖瘦体重的评估作为替代。适应的多重行为 有效改善(放大)癌症生存者健康的干预措施(1P01CA22997) 旨在对652名老年人、不活跃、超重或肥胖的人进行三种不同的生活方式干预 肥胖的癌症幸存者，其中很大一部分将是少数民族和农村人。干预措施 包括：1)为期6个月的饮食干预，旨在改善饮食质量和减肥，如 以及保持瘦体重；2)为期6个月的干预措施，旨在促进 有氧体育活动；3)12个月的饮食和运动干预，将两者结合起来 同时节食和锻炼(效果将根据以下各项的组合进行评估 按顺序进行干预1和2)。访问护士将评估身体功能并执行 按基线和每六个月在家中进行静脉采血健康评估； 参与者还将完成评估饮食、体力活动和总体质量的调查 生活。我们建议使用以下方法来衡量这些干预措施对肌肉质量的影响 新的D3-肌酸(D3Cr)稀释法。我们已经证明了这一非 侵入性方法可以在大型队列研究(MROS)和D3Cr肌肉中实施 质量与功能能力和残疾风险密切相关，而且年龄- 肌肉质量的相关减少与步态速度较慢和减少有关 力量。使用DXA衍生的瘦肉量没有观察到这些关联。研究对象将 摄入60毫克的D3Cr胶囊，48-96小时后产生空腹尿样，用于 评估D3-肌酸浓缩以确定肌酸池的大小，因为 人体总肌酸的98%存在于肌肉、肌肉块中。这是第一次， 运动引起的肌肉质量变化与体重减轻的关系 将评估这一老年高危人群的功能能力和体力活动 癌症幸存者。

We propose to add the measurement of muscle mass to an already funded program project grant. Rapid declines in physical functioning often occur after the diagnosis of cancer, especially among older cancer survivors; however, a handful of diet and exercise interventions have been found to ameliorate these losses. The contribution of muscle mass and changes in muscle mass in older men and women, particularly those who have survived cancer is not well characterized, partly due to the inability to directly and accurately quantify skeletal muscle mass and reliance on assessments of lean mass as a surrogate. The Adapting MultiPLe behavior Interventions that eFfectively Improve (AMPLIFI) Cancer Survivor Health (1P01CA22997) is aimed at testing three distinct lifestyle interventions among 652 older, inactive, overweight or obese cancer survivors, a large proportion of whom will be minority and rural. The interventions include: 1) a 6-month dietary intervention aimed at improving diet quality and weight loss, as well as preserving lean body mass; 2) a 6-month intervention that is aimed at promoting aerobic physical activity; and 3) a 12-month diet and exercise intervention that combines both diet and exercise simultaneously (and effects will be evaluated against the combination of interventions 1 and 2 in sequence). Visiting nurses will assess physical function and perform phlebotomy at home health assessments scheduled at baseline and every six months; participants also will complete surveys that assess diet, physical activity and overall quality of life. We propose to measure the effects of these interventions on muscle mass using the novel D3-creatine (D3Cr) dilution method. We have demonstrated that this non- invasive method can be implemented in a large cohort study (MrOS) and that D3Cr muscle mass is strongly associated with functional capacity and risk of disability and that age- associated decreases in muscle mass are associated with slower gait speed and decreased strength. These associations were not observed using DXA derived lean mass. Subjects will ingest a 60 mg capsule of D3Cr and produce a fasting urine sample 48 – 96 hours later for the assessment of D3-Creatinine enrichment to determine creatine pool size and, because 98% of total body creatine is found in muscle, muscle mass. For the first time, the relationship between changes in muscle mass resulting from exercise and weight loss and functional capacity and physical activity will be assessed in this at-risk population of older cancer survivors.