Protein Ingestion to Stimulate Myofibrillar Protein Synthesis Requires Greater Relative Protein Intakes in Healthy Older Versus Younger Men
Protein Ingestion to Stimulate Myofibrillar Protein Synthesis Requires Greater Relative Protein Intakes in Healthy Older Versus Younger Men
复制标题
DOI：
10.1093/gerona/glu103
复制
发表时间：
2015-01-01
影响因子：
5.1
通讯作者：
Phillips, Stuart M.
中科院分区：
文献类型：
--
作者：
Moore, Daniel R.;Churchward-Venne, Tyler A.;Phillips, Stuart M.
背景需要足够的蛋白质摄入介导的刺激肌原纤维蛋白合成（MPS）来维持骨骼肌质量。目前尚不清楚每餐蛋白质摄入量需要最大限度地刺激老年男性的反应，以及它是否与年轻男性不同。我们回顾性分析了来自我们实验室的数据，这些数据测量了健康老年（类似于71岁）和年轻（类似于22岁）男性的MPS，这些男性在摄入不同量（0-40 g）的优质膳食蛋白质作为单次推注后，通过启动L-环-[C-13（6）]苯丙氨酸的恒定输注，并将其标准化为体重和瘦体重（LBM）。老年男性（0.027 +/- 0.04%/h;平均值+/-95%CI）和年轻男性（0.028 +/- 0.03%/h）之间的基础MPS率无差异（p = 0.53）。双相线性回归和断点分析显示，第一线段的斜率较低（p < .05），MPS在摄入0.40 +/- 0.19和0.24 +/- 0.06 g/kg体重后达到平台期（p = 0.055）和0.60 +/- 0.29和0.25 +/- 0.13 g/kg瘦体重（p <0.01）。这是首次报告年轻和老年男性中MPS的相对（体重）蛋白质摄入剂量反应。我们的数据表明，健康的老年男性对低蛋白质摄入量不太敏感，需要更大的相对蛋白质摄入量，在一顿饭中，比年轻男性，最大限度地刺激餐后MPS率。当开发营养解决方案以最大化MPS以维持或增强肌肉质量时，应考虑这些结果。
Background. Adequate protein ingestion-mediated stimulation of myofibrillar protein synthesis (MPS) is required to maintain skeletal muscle mass. It is currently unknown what per meal protein intake is required to maximally stimulate the response in older men and whether it differs from that of younger men.Methods. We retrospectively analyzed data from our laboratories that measured MPS in healthy older (similar to 71 years) and younger (similar to 22 years) men by primed constant infusion of L-ring-[C-13(6)] phenylalanine after ingestion of varying amounts (0-40 g) of high-quality dietary protein as a single bolus and normalized to body mass and, where available, lean body mass (LBM).Results. There was no difference (p = .53) in basal MPS rates between older (0.027 +/- 0.04%/h; means +/- 95% CI) and young (0.028 +/- 0.03%/h) men. Biphase linear regression and breakpoint analysis revealed the slope of first line segment was lower (p < .05) in older men and that MPS reached a plateau after ingestion of 0.40 +/- 0.19 and 0.24 +/- 0.06 g/kg body mass (p = .055) and 0.60 +/- 0.29 and 0.25 +/- 0.13 g/kg lean body mass (p < .01) in older and younger men, respectively.Conclusions. This is the first report of the relative (to body weight) protein ingested dose response of MPS in younger and older men. Our data suggest that healthy older men are less sensitive to low protein intakes and require a greater relative protein intake, in a single meal, than young men to maximally stimulate postprandial rates of MPS. These results should be considered when developing nutritional solutions to maximize MPS for the maintenance or enhancement of muscle mass with advancing age.