蛋白质中亮氨酸的含量是健康老年女性在休息和抗阻运动后短期和长期肌肉蛋白质合成反应的决定因素：一项随机对照试验。

Protein leucine content is a determinant of shorter- and longer-term muscle protein synthetic responses at rest and following resistance exercise in healthy older women: a randomized, controlled trial.

机构信息

Department of Kinesiology, and Division of Physical Medicine and Rehabilitation, McMaster University, Hamilton, ON, Canada.

PepsiCo R&D Nutrition, Barrington, IL.

出版信息

Am J Clin Nutr. 2018 Feb 1;107(2):217-226. doi: 10.1093/ajcn/nqx028.

DOI:10.1093/ajcn/nqx028

PMID:29529146

Abstract

BACKGROUND

Older women may not be consuming enough protein to maintain muscle mass. Augmentation of protein intake with leucine may enhance the muscle protein synthetic response in older women to aid in maintaining muscle mass.

OBJECTIVE

We measured the acute (hourly) and integrated (daily) myofibrillar protein synthesis (myoPS) response to consumption of a high-quality mixed protein beverage compared with an isonitrogenous protein beverage with added leucine.

DESIGN

In a parallel design, free-living, healthy older women (aged 65-75 y, n = 11/group) consumed a fixed, weight-maintaining diet with protein at 1.0 g · kg-1 · d-1 and were randomly assigned to twice-daily consumption of either 15 g milk protein beverage containing 4.2 g leucine (LEU) or 15 g mixed protein (milk and soy) beverage containing 1.3 g leucine (CON). Unilateral leg resistance exercise allowed a determination of acute ([13C6]-phenylalanine infusion, hourly rate) and integrated (deuterated water ingestion, daily rate) exercised and rested myoPS responses.

RESULTS

Acute myoPS increased in response to feeding in the rested (CON: 13% ± 4%; LEU: 53% ± 5%) and exercised (CON: 30% ± 4%; LEU: 87% ± 7%) leg in both groups, but the increase was greater in LEU (P < 0.001). Integrated myoPS increased during the supplementation period in both legs (rested: 9% ±1%; exercised: 17% ± 2%; P < 0.001) in LEU, but in the exercised leg only (7% ± 2%; P < 0.001) in CON.

CONCLUSIONS

A 15-g protein-containing beverage with ∼4 g leucine induced greater increases in acute and integrated myoPS than did an isonitrogenous, isoenergetic mixed-protein beverage. Declines in muscle mass in older women may be attenuated with habitual twice-daily consumption of a protein beverage providing 15 g protein and higher (4.2 g/serving) amounts of leucine. This trial was registered at clinicaltrials.gov as NCT02282566.

摘要

背景

老年女性可能无法摄入足够的蛋白质来维持肌肉量。增加亮氨酸摄入的蛋白质可能会增强老年女性的肌肉蛋白合成反应，以帮助维持肌肉量。

目的

我们测量了摄入高质量混合蛋白饮料与添加亮氨酸的等氮蛋白饮料相比，对肌原纤维蛋白合成（myoPS）的急性（每小时）和综合（每日）反应。

设计

在平行设计中，自由生活的健康老年女性（年龄 65-75 岁，每组 11 人）摄入维持体重的固定蛋白质饮食，蛋白质摄入量为 1.0 g·kg-1·d-1，并随机分为每日两次摄入 15 g 牛奶蛋白饮料，含 4.2 g 亮氨酸（LEU）或 15 g 混合蛋白（牛奶和大豆）饮料，含 1.3 g 亮氨酸（CON）。单侧腿部抗阻运动允许确定急性（[13C6]-苯丙氨酸输注，每小时率）和综合（氘水摄入，每日率）运动和休息时的 myoPS 反应。

结果

休息时（CON：13%±4%；LEU：53%±5%）和运动时（CON：30%±4%；LEU：87%±7%），两条腿的喂养均导致急性 myoPS 增加，但 LEU 增加更大（P<0.001）。在 LEU 中，两条腿的补充期间，综合 myoPS 均增加（休息时：9%±1%；运动时：17%±2%；P<0.001），但在 CON 中仅在运动腿中增加（7%±2%；P<0.001）。

结论

含有约 4 g 亮氨酸的 15 g 蛋白质饮料比等氮、等能量混合蛋白饮料引起的急性和综合 myoPS 增加更大。习惯性每日两次摄入提供 15 g 蛋白质和更高（4.2 g/份）亮氨酸的蛋白质饮料可能会减轻老年女性的肌肉质量下降。该试验在 clinicaltrials.gov 注册为 NCT02282566。