Chanet Audrey, Verlaan Sjors, Salles Jérôme, Giraudet Christophe, Patrac Véronique, Pidou Véronique, Pouyet Corinne, Hafnaoui Nordine, Blot Adeline, Cano Noël, Farigon Nicolas, Bongers Anke, Jourdan Marion, Luiking Yvette, Walrand Stéphane, Boirie Yves
University of Clermont Auvergne, INRA, Human Nutrition Unit, Centre for Research in Human Nutrition Auvergne, Clermont-Ferrand, France.
Nutricia Research, Nutricia Advanced Medical Nutrition, Utrecht, Netherlands.
J Nutr. 2017 Dec;147(12):2262-2271. doi: 10.3945/jn.117.252510. Epub 2017 Aug 23.
A promising strategy to help older adults preserve or build muscle mass is to optimize muscle anabolism through providing an adequate amount of high-quality protein at each meal. This "proof of principle" study investigated the acute effect of supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink on postprandial muscle protein synthesis and longer-term effect on muscle mass in healthy older adults. A randomized, placebo-controlled, double-blind study was conducted in 24 healthy older men [mean ± SD: age 71 ± 4 y; body mass index (in kg/m) 24.7 ± 2.8] between September 2012 and October 2013 at the Unit of Human Nutrition, University of Auvergne, Clermont-Ferrand, France. Participants received a medical nutrition drink [test group; 21 g leucine-enriched whey protein, 9 g carbohydrates, 3 g fat, 800 IU cholecalciferol (vitamin D), and 628 kJ] or a noncaloric placebo (control group) before breakfast for 6 wk. Mixed muscle protein fractional synthesis rate (FSR) was measured at week 0 in the basal and postprandial state, after study product intake with a standardized breakfast with the use of l-[H]-phenylalanine tracer methodology. The longer-term effect of the medical nutrition drink was evaluated by measurement of appendicular lean mass, representing skeletal muscle mass at weeks 0 and 6, by dual-energy X-ray absorptiometry. Postprandial FSR (0-240 min) was higher in the test group than in the control group [estimate of difference (ED): 0.022%/h; 95% CI: 0.010%/h, 0.035%/h; ANCOVA, = 0.001]. The test group gained more appendicular lean mass than the control group after 6 wk (ED: 0.37 kg; 95% CI: 0.03, 0.72 kg; ANCOVA, = 0.035), predominantly as leg lean mass (ED: 0.30 kg; 95% CI: 0.03, 0.57 kg; ANCOVA, = 0.034). Supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink stimulated postprandial muscle protein synthesis and increased muscle mass after 6 wk of intervention in healthy older adults and may therefore be a way to support muscle preservation in older people. This trial was registered at www.trialregister.nl as NTR3471.
帮助老年人维持或增加肌肉量的一个有前景的策略是，每餐提供足量的优质蛋白质，以优化肌肉合成代谢。这项“原理验证”研究调查了用富含维生素D和亮氨酸的乳清蛋白医学营养饮品补充早餐，对健康老年人餐后肌肉蛋白质合成的急性影响，以及对肌肉量的长期影响。2012年9月至2013年10月期间，在法国克莱蒙费朗奥弗涅大学人类营养科，对24名健康老年男性[平均±标准差：年龄71±4岁；体重指数（kg/m²）24.7±2.8]进行了一项随机、安慰剂对照、双盲研究。参与者在早餐前6周内，每天饮用一种医学营养饮品[试验组；富含21克亮氨酸的乳清蛋白、9克碳水化合物、3克脂肪、800国际单位胆钙化醇（维生素D）和628千焦能量]或无热量安慰剂（对照组）。在第0周，使用l-[H]-苯丙氨酸示踪法，在基础状态和餐后状态下，于摄入研究产品并搭配标准化早餐后，测量混合肌肉蛋白质分数合成率（FSR）。通过双能X射线吸收法测量第0周和第6周的附属器瘦体重（代表骨骼肌量），评估医学营养饮品的长期效果。试验组餐后FSR（0 - 240分钟）高于对照组[差异估计值（ED）：0.022%/小时；95%置信区间：0.010%/小时，0.035%/小时；协方差分析，P = 0.001]。6周后，试验组比对照组获得了更多的附属器瘦体重（ED：0.37千克；95%置信区间：0.03，0.72千克；协方差分析，P = 0.035），主要是腿部瘦体重（ED：0.30千克；95%置信区间：0.03，0.57千克；协方差分析，P = 0.034）。在健康老年人中，用富含维生素D和亮氨酸的乳清蛋白医学营养饮品补充早餐，可刺激餐后肌肉蛋白质合成，并在干预6周后增加肌肉量，因此可能是一种帮助老年人维持肌肉的方法。该试验已在www.trialregister.nl注册，注册号为NTR3471。
