Protein Ingestion before Sleep Increases Overnight Muscle Protein Synthesis Rates in Healthy Older Men: A Randomized Controlled Trial
Protein Ingestion before Sleep Increases Overnight Muscle Protein Synthesis Rates in Healthy Older Men: A Randomized Controlled Trial
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DOI：
10.3945/jn.117.254532
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发表时间：
2017-12-01
影响因子：
4.2
通讯作者：
van Loon, Luc J. C.
中科院分区：
文献类型：
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作者：
Kouw, Imre W. K.;Holwerda, Andrew M.;van Loon, Luc J. C.
背景：骨骼肌质量随着年龄的增长而减少是由于蛋白质摄入的合成代谢反应迟钝。目的：我们评估了前蛋白摄入对老年男性膳食蛋白质消化吸收动力学和夜间肌肉蛋白质合成率的影响。方法：采用随机、双盲、平行设计，（平均+/-SEM年龄：72+/-1岁）睡前摄入40 g酪蛋白（PRO40）、20 g酪蛋白（PRO20）、20 g酪蛋白加1.5 g亮氨酸（PRO20+LEU）或安慰剂。在睡眠期间，将摄入固有的L-[1-C-13]-苯丙氨酸和L-[1-C-13]-亮氨酸标记蛋白与静脉注射L-[环-H-2（5）]-苯丙氨酸和L-[1-C-13]-亮氨酸相结合。结果：蛋白质摄入后，外源性苯丙氨酸的出现率增加，但PRO 40组高于PRO 20组和PRO 20 +LEU组（P < 0.05）。过夜肌原纤维蛋白合成速率（基于L-[环-H-2（5）]-苯丙氨酸）在安慰剂、PRO 20、PRO 20 +LEU和PRO 40中分别为0.033%+/-0.002%/h、0.037%+/-0.003%/ h、0.039%+/-0.002%/ h和0.044%+/-0.003%/ h，PRO40组高于安慰剂组（P = 0.02）。基于L-[1-C-13]亮氨酸示踪剂的观察结果相似（安慰剂：0.047%+/-0.004%/ h和PRO 40：0.058%+/-0.003%/ h，P = 0.08）。更多蛋白质衍生的氨基酸（L-[1-C-13]-苯丙氨酸）在PRO 40中比在PRO 20中掺入肌原纤维蛋白（分别为0.033+/-0.002和0.019+/-0.002 MPE，P < 0.001），并倾向于高于PRO20+LEU（0.025+/-0.002MPE，P = 0.06）.结论：健康老年男性在睡眠期间，睡前摄入的蛋白质在整个夜间被适当消化和吸收，为肌原纤维蛋白合成提供前体。睡前摄入40克蛋白质会增加过夜睡眠期间肌原纤维蛋白质的合成速率。这些发现为一种新的营养策略提供了科学依据，以支持在衰老和疾病中保持肌肉质量。
Background: The loss of skeletal muscle mass with aging has been attributed to the blunted anabolic response to protein intake. Presleep protein ingestion has been suggested as an effective strategy to compensate for such anabolic resistance.Objective: We assessed the efficacy of presleep protein ingestion on dietary protein digestion and absorption kinetics and overnight muscle protein synthesis rates in older men.Methods: In a randomized, double-blind, parallel design, 48 older men (mean+/-SEM age: 72+/-1 y) ingested 40 g casein (PRO40), 20 g casein (PRO20), 20 g casein plus 1.5 g leucine (PRO20+LEU), or a placebo before sleep. Ingestion of intrinsically L-[1-C-13]-phenylalanine- and L-[1-C-13]-leucine-labeled protein was combined with intravenous L-[ring-H-2(5)]-phenylalanine and L-[1-C-13]-leucine infusions during sleep. Muscle and blood samples were collected throughout overnight sleep.Results: Exogenous phenylalanine appearance rates increased after protein ingestion, but to a greater extent in PRO40 than in PRO20 and PRO20+LEU (P < 0.05). Overnight myofibrillar protein synthesis rates (based on L-[ring-H-2(5)]-phenylalanine) were 0.033%+/-0.002%/ h, 0.037%+/-0.003%/ h, 0.039%+/-0.002%/ h, and 0.044%+/-0.003%/ h in placebo, PRO20, PRO20+LEU, and PRO40, respectively, and were higher in PRO40 than in placebo (P = 0.02). Observations were similar based on L-[1-C-13]leucine tracer (placebo: 0.047%+/-0.004%/ h and PRO40: 0.058%+/-0.003%/ h, P = 0.08). More protein-derived amino acids (L-[1-C-13]-phenylalanine) were incorporated into myofibrillar protein in PRO40 than in PRO20 (0.033+/-0.002 and 0.019+/-0.002 MPE, respectively, P < 0.001) and tended to be higher than in PRO20+LEU (0.025+/-0.002 MPE, P = 0.06).Conclusions: Protein ingested before sleep is properly digested and absorbed throughout the night, providing precursors for myofibrillar protein synthesis during sleep in healthy older men. Ingestion of 40 g protein before sleep increases myofibrillar protein synthesis rates during overnight sleep. These findings provide the scientific basis for a novel nutritional strategy to support muscle mass preservation in aging and disease.