Clinical Effectiveness of Protein and Amino Acid Supplementation on Building Muscle Mass in Elderly People: A Meta-Analysis

PLOS ONE, Dec 2019

Objective A major reason for the loss of mobility in elderly people is the gradual loss of lean body mass known as sarcopenia. Sarcopenia is associated with a lower quality of life and higher healthcare costs. The benefit of strategies that include nutritional intervention, timing of intervention, and physical exercise to improve muscle loss unclear as finding from studies investigating this issue have been inconsistent. We have performed a systematic review and meta-analysis to assess the ability of protein or amino acid supplementation to augment lean body mass or strength of leg muscles in elderly patients. Methods Nine studies met the inclusion criteria of being a prospective comparative study or randomized controlled trial (RCT) that compared the efficacy of an amino acid or protein supplement intervention with that of a placebo in elderly people (≥65 years) for the improvement of lean body mass (LBM), leg muscle strength or reduction associated with sarcopenia. Results The overall difference in mean change from baseline to the end of study in LBM between the treatment and placebo groups was 0.34 kg which was not significant (P = 0.386). The overall differences in mean change from baseline in double leg press and leg extension were 2.14 kg (P = 0.748) and 2.28 kg (P = 0.265), respectively, between the treatment group and the placebo group. Conclusions These results indicate that amino acid/protein supplements did not increase lean body mass gain and muscle strength significantly more than placebo in a diverse elderly population.

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Clinical Effectiveness of Protein and Amino Acid Supplementation on Building Muscle Mass in Elderly People: A Meta-Analysis

Yang Y-m (2014) Clinical Effectiveness of Protein and Amino Acid Supplementation on Building Muscle Mass in Elderly People: A Meta-Analysis. PLoS ONE 9(9): e109141. doi:10.1371/journal.pone.0109141 Clinical Effectiveness of Protein and Amino Acid Supplementation on Building Muscle Mass in Elderly People: A Meta-Analysis Zhe-rong Xu 0 Zhong-ju Tan 0 Qin Zhang 0 Qi-feng Gui 0 Yun-mei Yang 0 Conrad P. Earnest, Texas A&M University, United States of America 0 1 Department of Geriatrics, First Affiliated Hospital, School of Medicine, Zhejiang University , Hangzhou , China , 2 State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Department of Geriatrics, First Affiliated Hospital, School of Medicine, Zhejiang University , Hangzhou , China Objective: A major reason for the loss of mobility in elderly people is the gradual loss of lean body mass known as sarcopenia. Sarcopenia is associated with a lower quality of life and higher healthcare costs. The benefit of strategies that include nutritional intervention, timing of intervention, and physical exercise to improve muscle loss unclear as finding from studies investigating this issue have been inconsistent. We have performed a systematic review and meta-analysis to assess the ability of protein or amino acid supplementation to augment lean body mass or strength of leg muscles in elderly patients. Methods: Nine studies met the inclusion criteria of being a prospective comparative study or randomized controlled trial (RCT) that compared the efficacy of an amino acid or protein supplement intervention with that of a placebo in elderly people ($65 years) for the improvement of lean body mass (LBM), leg muscle strength or reduction associated with sarcopenia. Results: The overall difference in mean change from baseline to the end of study in LBM between the treatment and placebo groups was 0.34 kg which was not significant (P = 0.386). The overall differences in mean change from baseline in double leg press and leg extension were 2.14 kg (P = 0.748) and 2.28 kg (P = 0.265), respectively, between the treatment group and the placebo group. Conclusions: These results indicate that amino acid/protein supplements did not increase lean body mass gain and muscle strength significantly more than placebo in a diverse elderly population. - Sarcopenia is an age related loss of muscle mass and strength, and is associated with a lower quality of life resulting from a reduced ability to perform daily living tasks [1]. Sarcopenia results in increased healthcare costs of approximately $900 per elderly adult which in the USA is approximately $18.5 billion per year [2]. Prevalence of sarcopenia differs by gender, living circumstances, and continent: 13.2% of Chinese men and 4.8% of Chinese women who are $70 years of age have sarcopenia, while 4570% and 717.5% of American men and 2%59% and 4 10% of American women have sarcopenia, respectively [3]. Agerelated muscle loss is highly prevalent in nursing homes, with rates being as high as 68% in elderly men and 21% in elderly females [4], whereas community dwelling elderly have lower prevalence rates in males (10%) but higher rates in women (33%) [5]. Inadequate nutrition, oxidative stress, low physical activity levels, inflammation, and reduced hormone concentrations contribute to age related muscle loss [6]. Possible strategies that reliably increase muscle mass and strength in the elderly have been actively investigated, but conclusions on the benefits of different nutritional interventions, timing of administration, and physical exercise from studies have been conflicting [720]. Several nutritional interventions such as creatine monohydrate, whey protein, caseinate, and essential amino acids appear to augment protein synthesis in muscles [1,21,22]. Numerous studies have found that these nutritional supplements enhance the magnitude of gain in lean body mass and muscle strength in older adults undergoing exercise training [1,6,15]. Essential amino acid and leucine supplementation have increased protein synthesis in muscles and are thought to be better strategies for offsetting muscle loss than intact protein [7,16,2224], due in part to their higher absorption [22]. However, several studies that compared the effect of whey protein or amino acid supplementation on skeletal muscle mass, lean body mass, or strength in healthy elderly to that of placebos have not detected a significant difference between the two groups [8,17]. Many of the studies evaluating the impact of protein or amino acid supplementation on sarcopenia have been small and evaluated different supplements. In order to maximize the biostatical power of placebo controlled clinical trials, we have performed a meta-analysis to assess the ability of protein or amino acid supplementation to augment lean body mass or strength of leg muscles in elderly patients. Experimental Methods PubMed, Google Scholar, The Cochrane Library, EMBASE, and ClinicalTrials. (...truncated)


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Zhe-rong Xu, Zhong-ju Tan, Qin Zhang, Qi-feng Gui, Yun-mei Yang. Clinical Effectiveness of Protein and Amino Acid Supplementation on Building Muscle Mass in Elderly People: A Meta-Analysis, PLOS ONE, 2014, 9, DOI: 10.1371/journal.pone.0109141