肠内营养制剂和乳清蛋白对老年人肌肉质量和功能的影响

Effects of enteral nutrition and lactalbumin on muscle mass and function in the elderly

目的了解口服补充肠内营养制剂或优质蛋白质3个月对老年人肌肉质量和功能的影响。方法采用多中心、随机、对照研究。纳入年龄≥65岁有握力或步速下降的社区老年人74例，分为对照组26例、肠内营养制剂组（佳膳400kcal／d）27例及蛋白质组（乳清蛋白粉20g／d）21例。随访3个月，测定3组老年人步速、握力以及肌肉质量变化。结果对照组、肠内营养制剂（佳膳）组及蛋白质组四肢肌肉质量变化分别为一490．0g（95％CI：-801．9--245．5，P=0．001）、90．0g（95％CI：-346．8-442．0，P=0．241）和290．0g（95％CI：-746．6-20．1，P=0．007），肠内营养制剂组与对照组差异有统计学意义（P=0．019）；三组的握力较基线变化分别为1．3kg（95％CI：0．6（3．3）、4．1kg（95％CI：2．7-6．7）和2．1kg（95％CI：1．1-6．2），差异均有统计学意义（均P〈0．05）；步速较基线变化分别为0．1m／s（95％CI：0．1-0．2）、0．1m／s（95％CI：0．1-0．3）和0．2m／s（95％CI：0．1-0．3），均有明显改善（均P〈0．05）；但步速和握力变化在组问比较，差异无统计学意义（P〉0．05）。结论部分经口补充肠内营养制剂有利于维持社区老年人的肌肉质量，健康生活方式宣教干预可提高肌肉功能，但在此基础上补充肠内营养制剂或乳清蛋白质对肌肉功能的提高未见更多获益。

Objective To explore the effect of calories supplement or protein supplement on the skeletal muscle in the elderly. Methods The ambulatory elderly （265 yrs） with reduced handgrip strength and/or gait speed were enrolled, who did not suffer from any neurological or arthritic disease impairing mobility, or any severe pulmonary or heart disease, or chronic kidney failure. The subjects were recruited with their written informed consent from clinical practices in five hospitals in China. The subjects were randomized to control group（n= 26）, nutrition supplementation （Nutren 400 kcal/ d） group （n=27） or protein supplementation（Biopro Protein 20 g/d）group （n=21）. All the subjects were given healthy lifestyle education. The physical performances i.e. gait speed and handgrip strength were measured at baseline and at 2 and 3 months of followed up. Lean soft tissue mass （muscle mass） was measured by BIA at baseline and at 3 months of follow-up. Results A total of74 subjects completed the trial, including 26 in controls, 27 in Nutren, and 21 in protein group. At the end of the trial, the changes from baseline in appendicular muscle mass were -490.0 g （95 % CI= -801.9--245.5,P=0. 001）in control group, 90.0 g （95%CI： -846.8--442.0,P=0. 241） in Nutrengroup, and -290.0 g （95%CI：-746.6 20.1,P=0.007） in protein group. There were no significant difference in above indices among the three groups （P= 0. 051）, except between Nutren group and control group （P=0. 020）. The handgrip strength and gait speed in the three groups were improved obviously as compared with those at baseline, but not statistically significant between different groups. Conclusions Caloric supplementation group may have greater effect in maintaining muscle mass than the protein supplement group in the elderly. Both the caloric supplement and the protein supplement produce no additional effect on muscular function as compared with healthy lifestyle education.