Effect of Protein Supplementation Combined with Resistance Training on Muscle Mass, Strength and Function in the Elderly: A Systematic Review and Meta-Analysis

Plant protein, fibre and physical activity solutions to address poor appetite and prevent undernutrition in older adults: study protocol for the APPETITE randomised controlled trial

Reduced appetite with ageing is a key factor that may increase risk of undernutrition. The objective of this study is to determine the impact of innovative plant protein fibre (PPF) products within a personalised optimised diet (PD), a physical activity (PA) programme, and their combination on appetite, and other nutritional, functional and clinical outcomes in community-dwelling older adults in a multi-country randomised controlled intervention trial. One hundred and eighty community-dwelling adults (approximately sixty per trial centre in Germany, Ireland and Italy) aged 65 years and over will be recruited to participate in a 12-week, parallel-group, controlled trial. Participants will be randomised into one of four groups: 1, PD (incorporating two PPF products): 2, PA; 3, PD + PA; and 4, no intervention (control). The primary outcome is appetite measured by visual analogue scales and energy intake from an ad libitum test meal. Secondary outcomes include fasting and postprandial appetite-related gut hormones, Simplified Nutritional Appetite Questionnaire score, body composition, cardiorespiratory fitness, muscle strength, physical function and PA. In addition, self-efficacy, cognitive status, dietary restraint, depressive symptoms and compliance and acceptability of the intervention will be assessed. Metabolomic profiles, RMR, muscle motor unit properties and gut microbiome will also be assessed to explore potential underlying mechanisms. This multi-centre randomised controlled trial will advance knowledge on how PD (incorporating PPF products), PA and their combination influence appetite, nutritional status and related health outcomes in community-dwelling older adults and contribute to the prevention of undernutrition. Trial registration: Clinical Trials.gov Registry NCT05608707 (registered on 2 November 2022). Protocol Version: NCT05608707 Version 4 (registered on 29 September 2023).

Effect of Protein Supplementation Combined With Resistance Training in Gait Speed in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

We aimed to evaluate the effectiveness of the combination of protein supplementation and resistance training (RT), compared with RT alone or combined with a placebo, in improving gait speed.

METHODS

We searched PubMed, Web of Science, Cochrane Library, and SPORTDiscus databases, and 18 randomized controlled trials with 1,147 older participants were included for meta-analysis. Data were pooled as the effect sizes (Hedges' g) with 95% confidence interval (CI) of the gait speed (in meters per second). The random-effect meta-analysis, subgroup analyses, meta-regression, and sensitivity analysis were conducted.

RESULTS

The combination of protein supplementation and RT significantly improved gait speed (Hedges' g: 0.52 m/s, 95% confidence interval [0.17, 0.86], p = .005; I2 = 86.5%) compared with the RT alone. The subgroup analyses revealed that the significant improvement in gait speed postprotein intervention plus RT was observed only in participants who consumed protein after RT (Hedges' g: 0.90 m/s, 95% confidence interval [0.46, 1.33], p = .001; I2 = 79.6%). The pooled result did not significantly change after excluding any single study at one time or excluding smaller studies with large effect sizes.

CONCLUSIONS

Protein supplementation combined with RT could significantly improve the gait speed of older adults compared with RT alone. This positive effect is more pronounced in people who consume protein after RT.

Risk and determinants of sarcopenia in people with diabetes: a case-control study from Qatar Biobank cohort

BACKGROUND

Diabetes is associated with impairments in muscle mass and quality increasing the risk of sarcopenia. Thus, this study aimed to investigate the odds of sarcopenia and its associated risk factors among Qatari adults (> 18 years), while exploring the modulating effects of health and lifestyle factors.

METHODS

Using a case-control design, data from 767 participants (481 cases with diabetes and 286 controls without diabetes) was collected from Qatar Biobank (QBB). Sociodemographic, lifestyle factors including dietary intake, anthropometric and biochemical measures were analyzed. Handgrip strength, Dual X-ray absorptiometry (DXA), and Bio-impedance were used to assess muscle strength, muscle mass and muscle quality, respectively. The risk of sarcopenia was estimated using the European consensus on definition and diagnosis of sarcopenia.

RESULTS

Cases with diabetes were older (55 vs. 36 years; P < 0.001), had higher BMI (31.6 vs. 28.3 kg/m2; P < 0.001), lower cardiorespiratory fitness (50.0% "Moderate" fitness for cases, 62.9% "High" fitness for controls), and consumed less total (59.0 vs. 64.0; P = 0.004) and animal protein (39.0 vs. 42.0; P = 0.001), compared to controls based on a computed score. Participants with diabetes also had lower appendicular lean mass/BMI, handgrip strength, and higher probability of sarcopenia/probable sarcopenia (P < 0.005). Adjusted multiple logistic regression revealed that elevated cardiorespiratory fitness (β = 0.299, 95%CI:0.12-0.74) and blood triglycerides (β = 1.475, 95% CI: 1.024-2.124), as well as being a female (β = 0.086, 95%CI: 0.026-0.288) and having higher BMI (β = 0.908, 95%CI: 0.852-0.967) and ALM/BMI (β = 0.000, 95% CI: 0.000-0.007) are independent predictors (p < 0.05) of sarcopenia risk.

CONCLUSIONS

This study highlights the intricate relationship between diabetes and sarcopenia, revealing modifiable risk factors. Individuals with diabetes were found to have a higher likelihood of sarcopenia, which was associated with lower fitness levels and higher blood triglycerides. Protective factors against sarcopenia included being female and having higher BMI and ALM/BMI ratios.

Vitamin B12 status and skeletal muscle function among elderly: A literature review and pilot study on the effect of oral vitamin B12 supplementation in improving muscle function

Objectives

The objective of this study is to understand the role of vitamin B12 supplementation in improving skeletal muscle function among the elderly.

Methods

A literature review in the Medline database was conducted to understand the association between vitamin B12 and muscle function in Section A. In Section B, 28 healthy elderly participants aged ≥60 years were recruited in a cross-sectional design for estimation of plasma vitamin B12 status and assessment of upper limb muscle strength Maximal voluntary contraction (MVC) and muscle quality (expressed as MVC/total muscle mass). Participants were grouped based on vitamin B12 status into vitamin B12-depleted (<148 pmol/L) and replete (≥148 pmol/L) groups. In a quasi-experimental study design, the vitamin B12-depleted group (n = 14) received daily oral vitamin B12 supplementation of 100 μg for 3 months. All the study measures were repeated post-supplementation.

Results

Vitamin B12 deficiency was identified to contribute adversely to muscle strength, quality, and physical performance among older people in the extensive literature review. The pilot intervention study showed significant improvement in MVC and muscle quality (p < 0.050) post-vitamin B12 supplementation, comparable to the vitamin B12-replete group.

Conclusions

Vitamin B12 may have a crucial role in the maintenance of muscle function. 3-month oral vitamin B12 supplementation among subclinical vitamin B12 deficient elderly improved muscle strength and quality and reached levels similar to the vitamin B12 replete group.

Combined Nutrition with Exercise: Fueling the Fight Against Sarcopenia Through a Bibliometric Analysis and Review

Objective

This bibliometric analysis and review aimed to examine the current research status and trends in the combination of nutrition and exercise training for sarcopenia. Additionally, it sought to provide researchers with future research directions in this field.

Methods

Relevant publications were obtained from the Web of Science Core Collection (WoSCC) database, covering the period from January 1995 to October 2023. The collected publications were analyzed using CiteSpace, VOSviewer, Bibliometrix, and Review Manager.

Results

Out of the 2528 retrieved publications, the United States emerged as the leading contributor in terms of publication volume. The University of Texas System was identified as the most productive institution. Luc J C van Loon emerged as the most published author in this field. Analysis of keywords revealed recent hot topics and emerging areas of interest, such as "gut microbiota" and "mechanisms". Upon further evaluation, resistance training (RT) and protein supplementation were identified as the most commonly employed and effective methods.

Conclusion

RT and protein supplementation are widely recognized as effective strategies. Future research should focus on investigating the molecular aspects of sarcopenia. Moreover, the potential therapeutic role of gut microbiota in sarcopenia requires further comprehensive investigation in human subjects to establish its correlation.

High Sarcopenia Awareness Contrasts a Lack of Clinical Implementation Among Geriatric Rehabilitation Health Care Professionals in the Netherlands: EMPOWER-GR

BACKGROUND AND PURPOSE

Despite being associated with serious adverse outcomes, such as mortality, sarcopenia remains largely undiagnosed in older individuals. This study aimed to assess the awareness, practices, and barriers and enablers to clinical implementation of sarcopenia diagnosis and treatment among geriatric rehabilitation health care professionals in the Netherlands.

METHODS

As part of EMPOWER-GR, a cross-sectional survey among geriatric rehabilitation health care professionals working in the Netherlands was undertaken between September 23, 2020, and January 28, 2021. Professionals were recruited via a geriatric rehabilitation care provider, health care professional associations, professional networks of the research team, and social media. Descriptive statistics were used to assess the study outcomes.

RESULTS AND DISCUSSION

Of the 501 geriatric rehabilitation health care professionals, 12.2% were physicians, 23.0% physical therapist/occupational therapists, 30.3% dietitians, 19.6% nurses, and 11.0% health care assistants. The concept of sarcopenia was known by 83.8% of the participants, 92.5% correctly identified sarcopenia as low muscle mass and strength (and low physical performance), and 73.8% identified sarcopenia as very important in the management of older adults admitted for rehabilitation. Although 26.2% and 18.9% of the participants reported screening and diagnosing sarcopenia, respectively, in their current practice, only 3.0% adequately used the (revised) definition of the European Working Group on Sarcopenia in Older People. When sarcopenia has been diagnosed, 65.0% reported initiating treatment consisting of resistance exercise training (78.7%), food fortification/high-energy or protein diet (85.4%), and oral nutritional supplements (70.4%). Most important barriers to screening and diagnosis were lack of knowledge, access to tools, and equipment and time, while enablers were protocol implementation, access to training, and clear responsibilities.

CONCLUSIONS

Sarcopenia awareness is high among geriatric rehabilitation health care professionals in the Netherlands, but adequate screening and diagnosis is almost nonexistent in current clinical practice, which hampers interventions. Better knowledge, clear responsibilities, and access to tools and protocols, as well as prioritization, are needed for sarcopenia to be diagnosed and treated in geriatric rehabilitation in the Netherlands.

The association of appendicular lean mass and grip strength with low-density lipoprotein, very low-density lipoprotein, and high-density lipoprotein particle diameter: a Mendelian randomization study of the UK Biobank cohort

Aims

Reduced muscle mass and reduced strength are frequently associated with both alterations in blood lipids and poorer cardiometabolic outcomes in epidemiological studies; however, a causal association cannot be determined from such observations. Two-sample Mendelian randomization (MR) was applied to assess the association of genetically determined appendicular lean mass (ALM) and handgrip strength (HGS) with serum lipid particle diameter.

Methods and results

Mendelian randomization was implemented using summary-level data from the largest genome-wide association studies on ALM (n = 450 243), HGS (n = 223 315), and lipoprotein [low-density lipoprotein (LDL), very LDL (VLDL), and high-density lipoprotein (HDL)] particle diameters (n = 115 078). Inverse variance-weighted (IVW) method was used to calculate the causal estimates. Weighted median-based method, MR-Egger, and leave-one-out method were applied as sensitivity analysis. Greater ALM had a statistically significant positive effect on HDL particle diameter (MR-Egger: β = 0.055, SE = 0.031, P = 0.081; IVW: β = 0.068, SE = 0.014, P < 0.001) and a statistically significant negative effect on VLDL particle diameter (MR-Egger: β = -0.114, SE = 0.039, P = 0.003; IVW: β = -0.081, SE = 0.017, P < 0.001). Similarly, greater HGS had a statistically significant positive effect on HDL particle diameter (MR-Egger: β = 0.433, SE = 0.184, P = 0.019; IVW: β = 0.121, SE = 0.052, P = 0.021) and a statistically significant negative effect on VLDL particle diameter (MR-Egger: β = -0.416, SE = 0.163, P = 0.011; IVW: β = -0.122, SE = 0.046, P = 0.009). There was no statistically significant effect of either ALM or HGS on LDL particle diameter.

Conclusion

There were potentially causal associations between both increasing ALM and HGS and increasing HDL particle size and decreasing VLDL particle size. These causal associations may offer possibilities for interventions aimed at improving cardiovascular disease risk profile.

The effectiveness of protein supplementation combined with resistance exercise programs among community-dwelling older adults with sarcopenia: a systematic review and meta-analysis

OBJECTIVES

The combination of protein supplementation and resistance exercise shows promise for improving and maintaining muscle mass, strength, and performance in older adults with sarcopenia. This systematic review aimed to evaluate the effects of this combination on muscle mass, muscle strength, and physical performance in community-dwelling older adults with sarcopenia.

METHODS

We conducted a comprehensive search of 4 electronic databases: PubMed, Scopus, Embase, and the MEDLINE Library. The search covered literature from January 2013 to January 2023 and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two independent reviewers assessed the methodological quality of each study using the standard critical appraisal tool from the Joanna Briggs Institute (JBI). Meta-analysis was performed with the JBI Sumari program.

RESULTS

The review included 7 randomized controlled trials and 1 quasi-experimental study, encompassing a total of 854 participants aged 60 years and above. The study durations ranged from 10 weeks to 24 weeks. An analysis of standardized mean differences (SMDs) showed that protein supplementation combined with resistance exercise significantly increased muscle mass (SMD, 0.95; 95% confidence interval [CI], 0.13 to 1.78; p<0.05) and muscle strength (SMD, 0.32; 95% CI, 0.08 to 0.56; p<0.05).

CONCLUSIONS

Although the limited number of randomized controlled trials restricts the robustness of our conclusions, the evidence suggests that protein supplementation combined with resistance exercise is effective in enhancing muscle mass and strength in community-dwelling older adults with sarcopenia.

Sarcopenia knowledge of geriatric rehabilitation patients is low while they are willing to start sarcopenia treatment: EMPOWER-GR

BACKGROUND

Sarcopenia is prevalent in 20-50% of geriatric rehabilitation inpatients and is associated with functional dependence and mortality. The aim is to assess knowledge of geriatric rehabilitation inpatients on sarcopenia and their willingness and perceived barriers to start treatment.

METHODS

Enhancing Muscle POWER in Geriatric Rehabilitation (EMPOWER-GR) is an observational cohort of geriatric rehabilitation inpatients in Amsterdam, the Netherlands. Knowledge of sarcopenia, willingness and perceived barriers to treatment were assessed with a survey among inpatients. Importance of and self-perceived muscle health were rated using a visual analogue scale from 0 to 10. Descriptive statistics were used.

RESULTS

Inpatients' (n = 157, 59.9% female) mean age was 80.5 years (SD 7.3). Sarcopenia (European Working Group on Sarcopenia in Older People 2) prevalence was 21.7%. Five inpatients (3.2%) had heard of sarcopenia and had knowledge of its definition. Median muscle health was rated as 6 (interquartile range: 4-7). After explanation of treatment options, 67.1% were willing to start resistance exercise training (RET), 61.1% a high-protein diet and 55.7% oral nutritional supplements (ONS). Inpatients with sarcopenia were less willing (51.6%) to start a high-protein diet compared with inpatients without sarcopenia (77.8%) (P = 0.002); there was no difference for RET and ONS. Most reported barriers to treatment were ONS dislike (17.0%), too many other health issues (13.6%), doubts about treatment effectiveness/importance (12.9%) and RET intensity/difficulty (10.2%).

CONCLUSIONS

Knowledge of sarcopenia was low, while the majority of inpatients showed willingness to start treatment. A dislike of ONS, RET difficulty and too many other health issues may reduce willingness to start treatment. Education is important to increase sarcopenia-related health issues in geriatric rehabilitation inpatients.

Effects of Plant-Based Protein Interventions, with and without an Exercise Component, on Body Composition, Strength and Physical Function in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Maintaining muscle mass, strength, and function is crucial for our aging population. Exercise and dietary protein intake are recommended strategies; however, animal proteins have been the most studied. Plant-based protein sources have lower digestibility and incomplete amino acid profiles. However new innovative plant-based proteins and products may have overcome these issues. Therefore, this systematic review aimed to synthesize the current research and evaluate the effects of plant-based protein interventions compared to placebo on body composition, strength, and physical function in older adults (≥60 years old). The secondary aim was whether exercise improved the effectiveness of plant-based protein on these outcomes. Randomized controlled trials up to January 2023 were identified through Medline, EMBASE, CINAHL, and Cochrane Library databases. Studies contained a plant-protein intervention, and assessed body composition, strength, and/or physical function. Thirteen articles were included, all using soy protein (0.6-60 g daily), from 12 weeks to 1 year. Narrative summary reported positive effects on muscle mass over time, with no significant differences compared to controls (no intervention, exercise only, animal protein, or exercise + animal protein interventions). There was limited impact on strength and function. Meta-analysis showed that plant-protein interventions were comparable to controls, in all outcomes. In conclusion, plant-protein interventions improved muscle mass over time, and were comparable to other interventions, warranting further investigation as an anabolic stimulus in this vulnerable population.

Effects of 8 weeks of resistance training in combination with a high protein diet on body composition, muscular performance, and markers of liver and kidney function in untrained older ex-military men

Background

The effects of a high protein diet in combination with chronic resistance training (RT) on skeletal muscle adaptation responses in untrained older ex-military men is unknown. Therefore, we compared the effects of 8 weeks of RT in combination with either a high (1.6 g/kg/d) or low protein diet (0.8 g/kg/d) on body composition [skeletal muscle mass (SMM) and body fat percentage (BFP)], muscular strength, power, and endurance (upper and lower body), markers of liver [alanine transaminase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT)] and kidney (creatinine and urea) function, and lipid profile low-density lipoprotein (LDL), high-density lipoprotein (HDL), and cholesterol levels in a cohort of healthy, untrained older ex-military males.

Methods

Forty healthy untrained older ex-military males (age: 61 ± 2 yr, body mass index: 23.2 ± 1.3 kg.m^-2) performed 8 weeks (three sessions·w^-1) of RT with either 1.6 g/kg/d (RHP; n = 20) or 0.8 g/kg/d of protein (RLP; n = 20). Body composition (assessed by Inbody 720), muscular strength (1-RM for chest and leg press), power (Wingate test), endurance (75% 1-RM for chest and leg press), and markers of liver and kidney function (biochemical kits) were assessed pre and post-intervention.

Results

SMM and muscular strength (upper and lower body) increased post-intervention in both groups and were significantly greater in RHP compared to RLP, while muscular power increased to the same extent in both groups (p < 0.05) with no between-group differences (p > 0.05). In contrast, there were no post-intervention changes in muscular endurance, HDL, and BFP remained in either group (p > 0.05). ALT and creatinine significantly increased in RHP compared to RLP while GGT, AST, and urea only increased in the RLP group (p < 0.05). LDL and cholesterol significantly decreased in both groups (p < 0.05).

Conclusion

A daily intake of 1.6 g/kg/d protein was superior to 0.8 g/kg/d (current recommended daily intake) for promoting greater improvements in SMM and muscle strength and thus may be a more suitable level of intake for promoting such adaptive responses. Notwithstanding observed between-group differences in ALT and creatinine and the fact that levels remained within normal ranges, it is feasible to conclude that this daily protein intake is efficacious and well tolerated by healthy, untrained older ex-military males.

Association of Protein Intake with Handgrip Strength and Its Relation to Strength Exercise in Korean Adults Aged over 60 Years in the KNHANES (2014-18)

Weak handgrip strength (HGS) is associated with many negative health outcomes in older adults. There is evidence that with strength exercise, high protein intake leads to increased HGS. The goal of this study was to examine the relationship between weak HGS in older adults and dietary protein and it's relation to resistance exercise. Data on 8497 Korean adults aged over 60 years from the Korea National Health and Nutrition Examination Survey (2014-18) were analyzed. Dietary protein intake measured by 24-h recall were categorized as three levels: low (<0.8 g/kg body weight (BW)), adequate (≥0.8 g/kg BW and <1.2 g/kg BW), and high (≥1.2 g/kg BW). Complex sample multiple logistic regression analyses were carried out. The prevalence of weak HGS was 18.3 (0.7)% in men and 28.8 (0.9)% in women. In a multiple logistic regression analysis, low protein intake was significantly associated with higher risk of weak HGS in men, as compared with adequate protein intake, but this relationship was not statistically significant in women. The risk of weak HGS was significantly reduced for both men and women who engaged in strength exercise and increased their dietary protein intake. In this study, based on a representative sample of Koreans aged over 60, men with low protein intake had a higher risk of weak HGS than did men with adequate protein intake. Men and women with a higher protein intake who also engaged in strength exercises had a lower risk of weak HGS. Increasing protein intake and engaging in strength exercises may be an effective way to preserve muscle strength in older men and women.

Acceptability of a high-protein Mediterranean-style diet and resistance exercise protocol for cardiac rehabilitation patients: Involving service users in intervention design using a mixed-methods participatory approach

Background

Current cardiac rehabilitation (CR) practices focus on aerobic-style exercise with minimal nutrition advice. This approach may not be optimal for CR patients with reduced muscle mass and elevated fat mass. Higher protein, Mediterranean-style diets combined with resistance exercise (RE) may improve muscle mass and reduce the risk of future cardiovascular events, although such an approach is yet to be trialed in a CR population.

Objective

We explored patient perspectives on the proposed design of a feasibility study. Patients reflected on the acceptability of a proposed high-protein Mediterranean-style diet and RE protocol, emphasizing research methodology and the acceptability of the proposed recipes and exercises.

Design

We applied quantitative and qualitative (mixed methods) approaches. The quantitative approach involved an online questionnaire (n = 40) regarding the proposed study methodology and relevance. A subset of participants (n = 12) received proposed recipe guides and were asked to prepare several dishes and complete an online questionnaire regarding their experience. Another subset (n = 18) received links to videos of the proposed RE and completed a questionnaire regarding their impressions of them. Finally, semi-structured interviews (n = 7) were carried out to explore participants' impressions of the proposed diet and exercise intervention.

Results

Quantitative data indicated a high level of understanding of the intervention protocol and its importance within the context of this research. There was a high degree of willingness to participate in all aspects of the proposed study (>90%). The trialed recipes were enjoyed and found to be easy to make by a majority of participants (79 and 92.1%, respectively). For the proposed exercises 96.5% of responses agreed they would be willing to perform them and, 75.8% of responses agreed they would enjoy them. Qualitative analysis revealed that participants viewed the research proposal, diet, and exercise protocol in a positive light. The research materials were considered appropriate and well explained. Participants suggested practical recommendations for improving recipe guides and requested more individual-focused exercise recommendations, and more information on the specific health benefits of the diet and exercise protocols.

Conclusion

The study methodology and the specific dietary intervention and exercise protocol were found to be generally acceptable with some suggested refinements.

Synergistic Effect of Increased Total Protein Intake and Strength Training on Muscle Strength: A Dose-Response Meta-analysis of Randomized Controlled Trials

Background

Protein supplementation augments muscle strength gain during resistance training. Although some studies focus on the dose-response relationship of total protein intake to muscle mass or strength, the detailed dose-response relationship between total protein intake and muscle strength increase is yet to be clarified, especially in the absence of resistance training.

Objective

We aimed to assess the detailed dose-response relationship between protein supplementation and muscle strength, with and without resistance training.

Design

Systematic review with meta-analysis.

Data Sources

PubMed and Ichushi-Web (last accessed on March 23, 2022).

Eligibility Criteria

Randomized controlled trials investigating the effects of protein intake on muscle strength.

Synthesis Methods

A random-effects model and a spline model.

Results

A total of 82 articles were obtained for meta-analyses, and data from 69 articles were used to create spline curves. Muscle strength increase was significantly augmented only with resistance training (MD 2.01%, 95% CI 1.09–2.93) and was not augmented if resistance training was absent (MD 0.13%, 95% CI − 1.53 to 1.79). In the dose-response analysis using a spline model, muscle strength increase with resistance training showed a dose-dependent positive association with total protein intake, which is 0.72% (95% CI 0.40–1.04%) increase in muscle strength per 0.1 g/kg body weight [BW]/d increase in total protein intake up to 1.5 g/kg BW/d, but no further gains were observed thereafter.

Conclusion

Concurrent use of resistance training is essential for protein supplementation to improve muscle strength. This study indicates that 1.5 g/kg BW/d may be the most appropriate amount of total protein intake for maintaining and augmenting muscle strength along with resistance training.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00508-w.

Protein Supplementation for Strength and Functionality in Older Adults: Is There Still Any Doubt? A Brief Update Review

It is widely known that the aging process induces relevant impairments on both muscle morphology and function. In this sense, resistance training alongside proper protein intake are important strategies to mitigate the sarcopenia process in older individuals. However, adding protein supplementation (PS) to resistance training interventions for enhancing muscle strength and functional performance has shown mixed results in this population. Therefore, the present study aimed to review the most recent evidence regarding PS and its effects on muscle strength and functional parameters of older adults. In addition, the effect size of each individual study (post-pre intervention) was also calculated to provide further clinical relevance on the topic. The results of the studies included do not seem to support PS for healthy older adults with proper protein intake. However, further studies with other sample characteristics (very old, frail, obese, and inadequate protein consumption) must be carried out to better understand the effects of PS in an older population.

Effectiveness of a complex intervention of group-based nutrition and physical activity to prevent frailty in pre-frail older adults (SUPER): a randomised controlled trial

BACKGROUND

The increasing prevalence of frailty with age is becoming a public health priority in countries with ageing populations. Pre-frailty presents a window of opportunity to prevent the development of frailty in community-dwelling older adults. This study aimed to examine the effectiveness of a complex intervention that combined a nutrition-based intervention and a physical activity intervention, along with the effectiveness of each intervention individually, to reduce physical frailty in pre-frail older adults over 2 years.

METHODS

In this single-blind, 2 x 2 factorial, randomised, controlled trial, we recruited pre-frail community-dwelling older adults in Aotearoa New Zealand via mail through general medical practices. To be eligible, participants had to be pre-frail according to self-reported FRAIL scores of 1 or 2, aged 75 years or older (or 60 years or older for Māori and Pacific Peoples), not terminally ill or with advanced dementia as judged by a general practitioner, able to stand, medically safe to participate in low-intensity exercise, and able to use kitchen utensils safely. Participants were randomly allocated to receive an 8-week Senior Chef programme (SC group), a 10-week Steady As You Go programme (SAYGO group), a 10-week combined SC and SAYGO intervention (combined group), or a 10-week social programme (control group), using computer-generated block randomisation administered through an electronic data capture system by local study coordinators. Assessors were masked to group allocation for all assessments. SC is a group-based nutrition education and cooking class programme (3 h weekly), SAYGO is a group-based strength and balance exercise programme (1 h weekly), and the social control programme was a seated, group socialising activity (once a week). Masked assessors ascertained Fried frailty scores at baseline, end of intervention, and at 6, 12, and 24 months after the programme. The primary outcome was change in Fried frailty score at 2 years. Intention-to-treat analyses were completed for all randomised participants, and all participants who had a high (≥75%) adherence were analysed per protocol. This study is registered at ANZCTR, ACTRN12614000827639.

FINDINGS

Between May 12, 2016 and April 9, 2018, we assessed 2678 older adults for eligibility, of whom 468 (17%) consented and completed baseline assessment, with a mean age of 80·3 years (SD 5·1) and a mean Fried score of 1·9 (1·2); 59% were women. We randomly allocated these participants into the four groups: 117 in the SC group, 118 in the SAYGO group, 118 in the combined group, and 115 in the control group; 318 participants attended the 24-month follow-up: 89 in the SC group, 78 in the SAYGO group, 73 in the combined group, and 78 in the control group. At the 24-month follow-up, there were no differences in mean Fried scores between the intervention groups and the control group. No adverse events were reported.

INTERPRETATION

The study did not find that the combined SC and SAYGO programme was effective in reducing frailty in pre-frail older adults. Although some short-term benefits were observed in each individual programme, there was no clear evidence of long-term impact. Further research is needed to evaluate combinations of group-based programmes for community-dwelling older adults to optimise their physical function.

FUNDING

Health Research Council New Zealand and Ageing Well Challenge (Ministry of Business Innovation and Employment).

The Effects of Graded Protein Intake in Conjunction with Progressive Resistance Training on Skeletal Muscle Outcomes in Older Adults: A Preliminary Trial

Many studies have evaluated the effects of resistance training (RT) and protein intake to attenuate the age-related loss of skeletal muscle. However, the effects of graded protein intake with conjunctive RT in older adults are unclear. Older adults (n = 18) performed 10 weeks of whole-body RT with progressions to intensity and volume while consuming either a constant protein (CP) diet (0.8−1.0 g/kg/d) with no protein supplement or a graded protein (GP) diet progressing from 0.8 g/kg/d at week 1 to 2.2 g/kg/d at week 10 with a whey protein supplement. Data were collected prior to commencement of the RT protocol (PRE), after week 5 (MID), and after week 10 (POST). Dual Energy X-ray Absorptiometry derived lean/soft tissue mass, ultrasonography derived muscle thickness, and a proxy of muscle quality were taken at PRE and POST, while isokinetic dynamometry derived peak torque were taken at PRE, MID, and POST. This study demonstrated the feasibility of the RT protocol (attendance = 96%), and protein intake protocol (CP in range all weeks; GP deviation from prescribed = 7%). Peak torque, muscle quality scores, and appendicular lean/soft tissue mass demonstrated the main effects of time (p < 0.05) while no other main effects of time or group * time interactions were seen for any measure. In conclusion, RT improved appendicular lean/soft tissue mass, peak torque, and muscle quality, with no differential effects of graded or constant protein intake.

Community-based group physical activity and/or nutrition interventions to promote mobility in older adults: an umbrella review

BACKGROUND

Physical activity and a healthy diet are important in helping to maintain mobility with aging. This umbrella review aims to identify group-based physical activity and/or nutrition interventions for community-dwelling older adults that improve mobility-related outcomes.

METHODS

Five electronic databases (MEDLINE, Embase, CINAHL, Cochrane CENTRAL, Sociological Abstracts) were searched from inception to December 2021. Eligibility criteria included systematic reviews exploring the effectiveness of physical activity or structured exercise, alone or combined with nutrition interventions on mobility-related outcomes (aerobic capacity, physical function, balance, falls/safety, muscle strength, health-related quality of life/wellbeing). Interventions must have been delivered in a group setting to community-dwelling older adults aged 55+. Two reviewers independently performed eligibility screening, critical appraisal (using AMSTAR 2) and data extraction. The GRADE approach was used to reflect the certainty of evidence based on the size of the effect within each mobility-related outcome category. Older adult/provider research partners informed data synthesis and results presentation.

RESULTS

In total, 62 systematic reviews (1 high, 21 moderate, 40 low/critically low quality) were identified; 53 included physical activity only, and nine included both physical activity and nutritional supplements. No reviews included nutrition interventions alone. Combined aerobic/resistance, general physical activity, and mind-body exercise all improved physical function and balance (moderate-high certainty). Aerobic/resistance training improved aerobic capacity (high certainty). Resistance training and general physical activity improved muscle strength (moderate certainty). Aerobic/resistance training and general physical activity are likely to reduce falls among older adults (moderate certainty). There was no evidence of benefit for nutritional supplementation with physical activity.

CONCLUSIONS

Group-based physical activity interventions that combine aerobic and resistance, general PA and mind-body exercise can improve measures of mobility in community-dwelling older adults. We found no reviews focused on nutrition only, highlighting a gap in the literature.

Effects of Protein Supplementation Associated with Resistance Training on Body Composition and Muscle Strength in Older Adults: A Systematic Review of Systematic Reviews with Meta-analyses

BACKGROUND

There are some controversial findings regarding the benefits of combining protein supplementation with resistance training in order to optimize adaptations to training in older adults.

OBJECTIVE

The aim of this review was to summarize the evidence from meta-analyses assessing the effects of protein supplementation combined with resistance training on body composition and muscle strength in the older population.

METHODS

We included systematic reviews with meta-analyses of randomized clinical trials that examined the effects of protein and/or amino acid supplementation associated with resistance training compared with resistance training alone on lean body mass, muscle mass, and muscle strength in older people. The search was performed using the MEDLINE (PubMed), Embase, Cochrane Database of Systematic Reviews, Google Scholar, and OpenGrey databases. Methodological quality was assessed using the Assessing the Methodological Quality of Systematic Reviews 2 checklist, and the quality of evidence was determined using the Grading of Recommendations Assessment, Development and Evaluation system. The pooled effect estimates were computed from the standardized mean difference and the 95% confidence interval achieved by each meta-analysis, using random effects models.

RESULTS

Five reviews were included, all of moderate methodological quality. In the analyses, protein supplementation combined with resistance training was associated with greater increases in lean body mass and muscle mass when compared with resistance training alone. However, no differences were observed between the interventions on muscle strength increases. The quality of evidence ranged from moderate to very low.

CONCLUSION

Protein supplementation associated with resistance training induces greater increases in lean body mass compared with resistance training alone. In addition, it is suggested that the use of protein supplementation enhances gains in muscle mass but does not promote greater increases in muscle strength.

Effects of protein supplementation and exercise on delaying sarcopenia in healthy older individuals in Asian and non-Asian countries: A systematic review and meta-analysis

While there is growing research interest in the effects of nutrition and exercise on delaying sarcopenia, the results are inconclusive and there is scarce information on regional patterns. This review evaluated the effects of the combination of protein supplementation and exercise on muscle strength, mass and physical performance, compared to exercise alone or with a placebo, in healthy older adults in Asian and non-Asian countries. Fourteen studies were included in the analysis, involving a total of 888 healthy older adults (>60 years). A significant increase in the lower-extremity strength was observed in the combined intervention group compared to the exercise group in Asian countries (SMD: 0.24, 95% CI [0.00, 0.47], p = 0.048, I2 = 0.0%). No statistical differences were found relating to upper-extremity strength, muscle mass and physical performance. Protein supplementation combined with exercise provides additional benefit on lower-extremity strength in healthy older adults with sarcopenia in Asian countries.

Combating sarcopenia in geriatric rehabilitation patients: study protocol of the EMPOWER-GR observational cohort, sarcopenia awareness survey and randomised controlled feasibility trial

INTRODUCTION

Sarcopenia is highly prevalent in geriatric rehabilitation patients. Resistance exercise training (RET) combined with protein supplementation is recommended to increase muscle mass and strength in older adults. However, sarcopenia awareness, feasibility to diagnose and treat sarcopenia, and efficacy of treatment in geriatric rehabilitation patients remain to be established.

METHODS AND ANALYSIS

Enhancing Muscle POWER in Geriatric Rehabilitation (EMPOWER-GR) encompasses four pillars: (1) an observational cohort study of 200 geriatric rehabilitation inpatients determining sarcopenia prevalence, functional and nutritional status at admission; (2) a survey among these 200 patients and 500 healthcare professionals and semistructured interviews in 30 patients and 15 carers determining sarcopenia awareness and barriers/enablers regarding diagnostics and treatment; (3) a feasibility, single-centre, randomised, controlled, open-label, two parallel-group trial in 80 geriatric rehabilitation patients with sarcopenia. The active group (n=40) receives three RET sessions per week and a leucine and vitamin D-enriched whey protein-based oral nutritional supplement two times per day in combination with usual care for 13 weeks. The control group (n=40) receives usual care. Primary outcomes are feasibility (adherence to the intervention, dropout rate, overall feasibility) and change from baseline in absolute muscle mass at discharge and week 13. Secondary outcomes are feasibility (participation rate) and change from baseline at discharge and week 13 in relative muscle mass, muscle strength, physical and functional performance, mobility, nutritional status, dietary intake, quality of life and length of stay; institutionalisation and hospitalisation at 6 months and mortality at 6 months and 2 years; (4) knowledge sharing on sarcopenia diagnosis and treatment.

ETHICS AND DISSEMINATION

Ethical exemption was received for the observational cohort study, ethics approval was received for the randomised controlled trial. Results will be disseminated through publications in scientific peer-reviewed journals, conferences and social media.

TRIAL REGISTRATION NUMBER

NL9444.

Protein interventions augment the effect of resistance exercise on appendicular lean mass and handgrip strength in older adults: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Increased protein intake is suggested as a strategy to slow or reverse the loss of muscle mass and strength observed in sarcopenia, but results from studies that directly tested this possibility have been inconsistent.

OBJECTIVES

We assessed the evidence on the effects of whole protein supplementation or higher-protein diets, without the use of amino acids or supplements known to stimulate hypertrophy, alone or in combination with resistance exercise (RE) interventions, on lean body mass (LBM) and strength in older adults.

METHODS

A systematic search was conducted using PubMed, Medline, Web of Science, and Cochrane CENTRAL databases from January 1990 to July 2021. Randomized controlled trials that assessed the effects of protein supplementation and/or higher-protein dietary interventions in older adults (mean age ≥50 y) on total LBM, appendicular lean mass (ALM), and handgrip (HG) and knee extension (KE) strength were included.

RESULTS

Twenty-eight studies were identified. In pooled analysis, compared with lower protein controls, protein supplementation did not have a significant positive effect on total LBM [weighted mean difference in change (WMD): 0.34; 95% CI: -0.21, 0.89; I2 = 90.01%], ALM (WMD: 0.4; 95% CI: -0.01, 0.81; I2 = 90.38%), HG strength (WMD: 0.69; 95% CI: -0.69, 2.06; I2 = 94.52%), or KE strength (WMD: 1.88; 95% CI: -0.6, 4.35; I2 = 95.35%). However, in interventions that used also RE, statistically significant positive effects of protein were observed for ALM (WMD: 0.54; 95% CI: 0.03, 1.05; I2 = 89.76%) and HG (WMD: 1.71; 95% CI: 0.12, 3.30; I2 = 88.71%). Meta-regression revealed no significant association between age, per-meal protein dose, duration, and baseline protein intake with change in any outcome. Subgroup analysis revealed the statistically significant effects on ALM occurred only in sarcopenic/frail populations (WMD: 0.88; 95% CI: 0.51, 1.25; I2 = 79.0%). Most studies (n = 22) had some risk of bias.

CONCLUSIONS

In older adults performing RE, increased protein intake leads to greater ALM and HG strength compared with lower protein controls. Without RE, protein has no additional benefit on changes in total LBM, ALM, or HG strength.

Can supplemental protein to low-protein containing meals superimpose on resistance-training muscle adaptations in older adults? A randomized clinical trial

PURPOSE

To evaluate the effects of supplementing protein to the low-protein containing meals on selected parameters of muscle mass, strength, and functional capacity in older individuals undergoing resistance training.

METHODS

Thirty-one male and female older individuals (60 to 80 years) were randomized into either a whey protein/WP (n = 15, 20 g at breakfast + 20 g at dinner) or placebo-maltodextrin/PL (n = 16, 20 g at breakfast + 20 g at dinner) group. Both groups underwent a supervised, progressive resistance training (2×/week) program for 12 weeks. Maximal isometric voluntary contraction (MIVC) of knee extensors, muscle thickness (MT) of knee extensors and elbow flexors, rectus femoris muscle quality (MQ), body composition (as measured by DXA) and functional capacity [as measured by 30-s sit-to-stand (30ss) and timed-up-and-go tests (TUG)] were evaluated at baseline and after the 12-week intervention.

RESULTS

Knee extensor MIVC (WP ∆ = 11.9 ± 11.4% and PL ∆ = 12.9 ± 9.9%) was significantly increased over time, with no between-group differences (all p < 0.05 for main effect of time). Upper- and lower-limb MT were significantly increased over time, with no effect of supplementation (WP: ∆ = 7.0 ± 7.3%, PL: ∆ = 9.5 ± 10.3%; and WP: ∆ = 4.5 ± 5.8%, PL: ∆ = 14.7 ± 28.9%, respectively; all p = 0.001 for main effect of time, respectively). Total and upper-limb lean mass were significantly increased, irrespective of the dietary intervention (WP: ∆ = 0.2 ± 6.3%, PL: ∆ = 1.8 ± 2.9%; and WP: ∆ = 0.10 ± 0.03%, PL: ∆ = 0.15 ± 0.02%, respectively; all p < 0.05 for main effect of time). Main effects of time (all p < 0.05) were also found for 30SS and TUG (fast and usual speeds) (WP: ∆ = 18.2 ± 34.4%, PL: ∆ = 10.4 ± 16.9%; WP: ∆ = 5.4 ± 6.7%, PL: ∆ = 0.7 ± 6.0% and WP: ∆ = 3.3 ± 6.1%, PL: ∆ = 2.3 ± 5.2%, respectively).

CONCLUSION

Supplementing additional whey protein to the lowest-protein containing meals (i.e., ~20 g at breakfast and ~20 g at dinner, daily) did not further augment resistance training-induced neuromuscular adaptations (i.e. muscle strength and mass) in healthy older individuals.

Health Effects of Increasing Protein Intake Above the Current Population Reference Intake in Older Adults: A Systematic Review of the Health Council of the Netherlands

Whether older adults need more protein than younger adults is debated. The population reference intake for adults set by the European Food Safety Authority is 0.83 g/kg body weight (BW)/d based primarily on nitrogen balance studies, but the underlying data on health outcomes are outdated. An expert committee of the Health Council of the Netherlands conducted a systematic review (SR) of randomized controlled trials (RCTs) examining the effect of increased protein intake on health outcomes in older adults from the general population with an average habitual protein intake ≥0.8 g/(kg BW · d). Exposures were the following: 1) extra protein compared with no protein and 2) extra protein and physical exercise compared with physical exercise. Outcomes included lean body mass, muscle strength, physical performance, bone health, blood pressure, serum glucose and insulin, serum lipids, kidney function, and cognition. Data of >1300 subjects from 18 RCTs were used. Risk of bias was judged as high (n = 9) or "some concerns" (n = 9). In 7 of 18 RCTs, increased protein intake beneficially affected ≥1 of the tested outcome measures of lean body mass. For muscle strength, this applied to 3 of 8 RCTs in the context of physical exercise and in 1 of 7 RCTs without physical exercise. For the other outcomes, <30% (0-29%) of RCTs showed a statistically significant effect. The committee concluded that increased protein intake has a possible beneficial effect on lean body mass and, when combined with physical exercise, muscle strength; likely no effect on muscle strength when not combined with physical exercise, or on physical performance and bone health; an ambiguous effect on serum lipids; and that too few RCTs were available to allow for conclusions on the other outcomes. This SR provides insufficiently convincing data that increasing protein in older adults with a protein intake ≥0.8 g/(kg BW · d) elicits health benefits.

Supplement-based nutritional strategies to tackle frailty: A multifactorial, double-blind, randomized placebo-controlled trial

BACKGROUND

Sarcopenia plays a central role in the development of frailty syndrome. Nutrition and exercise are cornerstone strategies to mitigate the transition to frailty; however, there is a paucity of evidence for which dietary and exercise strategies are effective.

OBJECTIVE

This large, multifactorial trial investigated the efficacy of different dietary strategies to enhance the adaptations to resistance training in pre-frail and frail elderly.

METHODS

This was a single-site 16-week, double-blind, randomized, placebo-controlled trial conducted at the Clinical Hospital, School of Medicine - University of São Paulo, Sao Paulo, Brazil. Four integrated, sub-investigations were conducted to compare: 1) leucine vs. placebo; 2) whey vs. soy vs. placebo; 3) creatine vs. whey vs. creatine plus whey vs. placebo; 4) women vs. men in response to whey. Sub-investigations 1 to 3 were conducted in women, only. Two-hundred participants (154 women/46 men, mean age 72 ± 6 years) underwent a twice-a-week, resistance training program. The main outcomes were muscle function (assessed by dynamic and isometric strength and functional tests) and lean mass (assessed by DXA). Muscle cross-sectional area, health-related quality of life, bone and fat mass, and biochemical markers were also assessed.

RESULTS

We observed that leucine supplementation was ineffective to improve muscle mass and function. Supplementation with whey and soy failed to enhance resistance-training effects. Similarly, supplementation with neither whey nor creatine potentiated the adaptations to resistance training. Finally, no sex-based differences were found in response to whey supplementation. Resistance exercise per se increased muscle mass and function in all sub-investigations. There were no adverse effects.

CONCLUSION

Neither protein (whey and soy), leucine, nor creatine supplementation enhanced resistance training-induced adaptations in pre-frail and frail elderly, regardless of sex. These findings do not support the notion that some widely used supplement-based interventions can add to the already potent effects of resistance exercise to counteract frailty-related muscle wasting and dynapenia.

CLINICAL TRIAL REGISTRY

NCT01890382; https://clinicaltrials.gov/ct2/show/NCT01890382.

DATA SHARING

Data described in the manuscript will be made available upon request pending application.

Musculoskeletal Responses to Exercise plus Nutrition in Men with Prostate Cancer on Androgen Deprivation: A 12-month RCT

PURPOSE

Androgen deprivation therapy (ADT) for prostate cancer (PCa) has multiple adverse effects on musculoskeletal health. This 12-month randomised controlled trial aimed to assess the effects of multi-component exercise training combined with whey protein, calcium and vitamin D supplementation on bone mineral density (BMD), structure and strength, body composition, muscle strength and physical function in ADT-treated men.

METHODS

Seventy ADT-treated men were randomised to exercise plus supplementation (Ex+Suppl; n=34) or usual care (Control; n=36). Ex+Suppl involved thrice weekly progressive resistance training plus weight-bearing impact exercise with daily multi-nutrient supplementation. Primary outcomes were DXA hip and spine areal BMD. Secondary outcomes included: tibia and radius pQCT volumetric BMD, bone structure and strength; DXA body composition; pQCT muscle and fat cross-sectional area and muscle density; muscle strength and physical function.

RESULTS

Sixty men (86%) completed the study. Mean exercise and supplement adherence were 56% and 77%, respectively. There were no effects of the intervention on bone or body composition outcomes. Ex+Suppl improved leg muscle strength (net difference [95% CI] 14.5% [-0.2, 29.2], P=0.007) and dynamic mobility (four-square-step test time, -9.3% [-17.3, -1.3], P=0.014) relative to controls. Per-protocol analysis of adherent participants (≥66% exercise, ≥80% supplement) showed Ex+Suppl preserved femoral neck aBMD (1.9% [0.1, 3.8], P=0.026) and improved total body lean mass (1.0 kg [-0.23, 2.22], P=0.044) relative to controls.

CONCLUSION

Exercise training combined with multi-nutrient supplementation had limited effect on ameliorating the adverse musculoskeletal consequences of ADT, likely related to the modest intervention adherence.

Process Evaluation of a Combined Lifestyle Intervention for Community-Dwelling Older Adults: ProMuscle in Practice

Background and Objectives

The ProMuscle in Practice intervention combines resistance exercise training and dietary protein intake for community-dwelling older adults, implemented by health care professionals (HCPs). This study aimed to evaluate implementation and context of this intervention in Dutch health care practice.

Research Design and Methods

We conducted a randomized controlled multicenter intervention study in 5 Dutch municipalities. Eighty-two older adults received the 12-week intensive support intervention (resistance exercise training and individual dietary counseling) and the optional 12-week moderate support intervention (resistance exercise training and a nutrition course). Mixed method data were collected from both participants and HCPs (n = 37) on process indicators recruitment, dose received, acceptability, fidelity, applicability, and context.

Results

Overall, the intervention was feasible to implement and accepted by participants and HCPs. About two thirds of participants continued with the moderate support intervention after the first 12 weeks. The mean dose received for the training sessions was 83.6% in the intensive intervention, 63.6% in the moderate intervention, >90% for individual dietitian consultations, and 76.8% for the nutrition course. The intensive support intervention was implemented with high fidelity, whereas for the moderate support intervention resistance exercise trainings varied in implementation between exercise providers.

Discussion and Implications

A combined resistance exercise training and dietary protein intervention for community-dwelling older adults can be successfully implemented in practice. Well-tailored interventions, intensive supervision by skilled HCPs, social aspects, fidelity, and fit within real-world settings appeared essential for successful implementation. These elements are important for continuous intervention optimization to accomplish broader and successful implementation.

Association between malnutrition and stages of sarcopenia in geriatric rehabilitation inpatients: RESORT

BACKGROUND & AIMS

Malnutrition and sarcopenia coexist in older adults, yet they remain largely undiagnosed and untreated, despite available interventions. This study aimed to assess the prevalence, the coexistence of, and the association between malnutrition and sarcopenia in geriatric rehabilitation inpatients.

METHODS

REStORing health of acutely unwell adulTs (RESORT) is an observational, longitudinal cohort of geriatric rehabilitation inpatients. The association between malnutrition, diagnosed according to the Global Leadership Initiative on Malnutrition (GLIM) criteria and sarcopenia according to the revised definition of the European Working Group on Sarcopenia in Older People (EWGSOP2) (no sarcopenia, probable sarcopenia, confirmed sarcopenia and severe sarcopenia) was determined using multinomial logistic regression analyses, adjusted for age, sex, comorbidities and cognitive impairment.

RESULTS

Out of 506 geriatric rehabilitation inpatients, 51% were malnourished, 49% had probable sarcopenia, 0.4% had confirmed sarcopenia (non-severe) and 19% had severe sarcopenia. Malnutrition and probable sarcopenia and malnutrition and confirmed/severe sarcopenia coexisted in 23% and 13% of the 506 patients respectively. Malnutrition was not associated with probable sarcopenia (OR = 0.91, 95% CI = 0.58-1.42, p = 0.674) but with severe sarcopenia (OR = 2.07, 95% CI = 1.13-3.81, p = 0.019).

CONCLUSION

The prevalence, coexistence of, and the association between malnutrition and severe sarcopenia in geriatric rehabilitation inpatients warrant diagnosis at admission. Further research into feasible and effective interventions to counteract both conditions to improve geriatric rehabilitation outcomes is needed.

A Randomized Controlled Pilot Exercise and Protein Effectiveness Supplementation Study (EXPRESS) on Reducing Frailty Risk in Community-Dwelling Older People

This pilot study aimed to examine the feasibility and effectiveness of a 6-months multi-component exercise program combined with twice daily consumption of either rice (RicePro) or whey-based (WheyPro) protein supplements (2 × 20 g of protein) on gait speed, grip strength and physical performance in community-dwelling pre-frail and frail older adults. Secondary outcomes included: frailty score, muscle mass, quality of life, nutritional intake, cognitive performance, depression and physical activity levels. A total of 70 participants (mean age 73.34 ± 6.85 years) were randomly allocated to either RicePro (n = 36) or WheyPro (n = 34). No adverse events were reported in regards to the exercise, however, several gastrointestinal symptoms were noted with the whey protein causing two-fold more symptoms compared to the rice protein. No differences were found between the groups (p > 0.05), except the total consumed energy (kJ) (p = 0.014) and fat (g) (p = 0.012) which was significantly lower in WheyPro. The results indicate that the quality of protein may not be as important as long as a sufficient amount is consumed.

Dose-response relationship between protein intake and muscle mass increase: a systematic review and meta-analysis of randomized controlled trials

CONTEXT

Lean body mass is essential for health, yet consensus regarding the effectiveness of protein interventions in increasing lean body mass is lacking.

OBJECTIVE

The aim of this systematic review was to evaluate the dose-response relationship of the effects of protein intake on lean body mass.

DATA SOURCES

The PubMed and Ichushi-Web databases were searched electronically, and reference lists of the literature included here and in other meta-analyses were searched manually.

STUDY SELECTION

Randomized controlled trials evaluating the effects of protein intake on lean body mass were included.

DATA EXTRACTION

Two authors independently screened the abstracts; 5 reviewed the full texts.

RESULTS

A total of 5402 study participants from 105 articles were included. In the multivariate spline model, the mean increase in lean body mass associated with an increase in protein intake of 0.1 g/kg of body weight per day was 0.39 kg (95%CI, 0.36-0.41) and 0.12 kg (95%CI, 0.11-0.14) below and above the total protein intake of 1.3 g/kg/d, respectively.

CONCLUSIONS

These findings suggest that slightly increasing current protein intake for several months by 0.1 g/kg/d in a dose-dependent manner over a range of doses from 0.5 to 3.5 g/kg/d may increase or maintain lean body mass.

SYSTEMATIC REVIEW REGISTRATION

UMIN registration number UMIN000039285.

Effectiveness of Protein Supplementation Combined with Resistance Training on Muscle Strength and Physical Performance in Elderly: A Systematic Review and Meta-Analysis

The aim of this study was to evaluate the effectiveness of the combination of resistance training (RT) and protein supplementation (PS), compared to RT alone or combined with a placebo (plS), in the improvement of muscle strength and physical performance. The search strategy in PubMed, Cochrane Library, and Web of Sciences databases found a total of 294 studies. Once inclusion and exclusion criteria were applied, 16 studies were included for the qualitative analysis. A total of 657 healthy elderly (>60 years) participants were analysed. Finally, 15 articles were included in the quantitative analysis with one being excluded due to issues with data availability. Upper-limb, lower-limb, and handgrip strength were the primary outcomes of the meta-analysis. The secondary outcomes, related to physical performance, were Short Physical Performance Battery (SPPB), gait speed, and the five-chair-rise test (5CRT). The main results of the meta-analysis show no statistical differences for upper-limb (SMD: 0.56, 95% CI: -0.09, 1.21, p = 0.09, I2 = 68%), lower-limb (SMD: 0.00, 95% CI: -0.18, 0.18, p = 1.0, I2 = 11%), and handgrip strength (SMD: 0.03, 95% CI: -0.26, 0.32, p = 0.84, I2 = 0%) between the RT + PS and the RT alone (or combined with plS). Moreover, no statistical differences were found relating to physical performance. In view of these results, protein supplementation combined with RT does not provide additional benefits compared to RT alone or with plS in healthy elderly adults.

Intake of polyunsaturated fatty acids and ω-3 are protective factors for sarcopenia in kidney transplant patients

OBJECTIVES

The aim of this study was to associate dietary intake with sarcopenia and its components in kidney transplant patients (KTPs).

METHODS

A cross-sectional study was performed with 125 KTPs. Strength was evaluated by handgrip strength (HGS) and appendicular muscle mass was estimated by bioelectrical impedance. Functional capacity was assessed by 4-m walking test. Sarcopenia was diagnosed by revised European Consensus on Definition and Diagnosis (2019). Dietary assessment was carried out through two 24-h dietary recalls. It evaluated the consumption of energy (kcal), carbohydrates, protein (total and from animal and vegetable food sources), total fat, saturated fatty acids, monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and ω-3 (g) and ω-6 (g).

RESULTS

Intake of ω-3 was positively associated with appendicular skeletal muscle mass index (ASMI; kg/m²). The greater intake of PUFA (g and %) and ω-3 (g) was associated with lower chance to present low ASMI and sarcopenia. None of the other dietary components evaluated in the present study were associated with ASMI and sarcopenia. Walking speed and HGS were not associated with dietary variables.

CONCLUSIONS

Intake of ω-3 and PUFAs are protective factors for sarcopenia and low muscle mass, but not for strength and functional capacity, in KTPs.

Effects of low-dose milk protein supplementation following low-to-moderate intensity exercise training on muscle mass in healthy older adults: a randomized placebo-controlled trial

PURPOSE

The purpose of this study was to examine whether long-term ingestion of low-dose milk protein supplementation causes a greater increase in muscle mass and strength of older adults during low-to-moderate intensity exercise training intervention than isocaloric carbohydrate.

METHODS

In a randomized, double-blind, and placebo-controlled design, 122 healthy older adults (60-84 year) received either an acidified milk protein drink containing 10 g of milk protein (MILK; n = 61) or an isocaloric placebo drink (PLA; n = 61) daily throughout 6 months of body weight and medicine ball exercise training. Measurements before and after the intervention included body composition, physical performance and blood biochemistry.

RESULTS

Lean body mass significantly increased in the MILK group (+ 0.54 kg, p < 0.001), but did not change in the PLA group (- 0.10 kg, p = 0.534). The increases in the MILK group were significantly greater than in the PLA group (p = 0.004). Fat mass (- 0.77 kg) and plasma uric acid levels (- 0.3 mg/dL) significantly decreased only in the MILK group (p < 0.001), with a significant group difference (p = 0.002 and p < 0.001, respectively). Most of the physical performance tests significantly improved in both groups, but no group differences were found.

CONCLUSION

We conclude that low-dose milk protein supplementation (10 g of protein/day) combined with low-to-moderate intensity exercise training is associated with increased muscle mass, but not improved physical performance compared to carbohydrate combined with exercise in healthy older adults. This study was registered in the UMIN Clinical Trials Registry (UMIN000032189).

The Role of Protein Intake and its Timing on Body Composition and Muscle Function in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Increased protein intake has been suggested to improve gains in muscle mass and strength in adults. Furthermore, the timing of protein intake has been discussed as a margin of opportunity for improved prevention measures.

OBJECTIVE

This systematic review investigated the effect of protein supplementation on body composition and muscle function (strength and synthesis) in healthy adults, with an emphasis on the timing of protein intake.

METHODS

Randomized controlled trials were identified using PubMed, Web of Science, CINAHL, and Embase, up to March 2019. For meta-analyses, data on lean body mass (LBM), handgrip strength, and leg press strength were pooled by age group (mean age 18-55 or >55 y) and timing of protein intake. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach.

RESULTS

Data from 65 studies with 2907 participants (1514 men and 1380 women, 13 unknown sex) were included in the review. Twenty-six, 8, and 24 studies were used for meta-analysis on LBM, handgrip strength, and leg press strength, respectively. The protein supplementation was effective in improving (mean difference; 95% CI) LBM in adults (0.62 kg; 0.36, 0.88) and older adults (0.46 kg; 0.23, 0.70), but not handgrip strength (older adults: 0.26 kg; -0.51, 1.04) and leg press strength (adults: 5.80 kg; -0.33, 11.93; older adults: 1.97 kg; -2.78, 6.72). Sensitivity analyses removing studies without exercise training had no impact on the outcomes. Data regarding muscle synthesis were scarce and inconclusive. Subgroup analyses showed no beneficial effect of a specific timing of protein intake on LBM, handgrip strength, and leg press strength.

CONCLUSION

Overall, the results support the positive impact of protein supplementation on LBM of adults and older adults, independently of intake timing. Effects on muscle strength and synthesis are less clear and need further investigation. This systematic review was registered on PROSPERO as CRD42019126742.

Nutrition and Muscle Strength, As the Key Component of Sarcopenia: An Overview of Current Evidence

Much has been achieved by recent research to increase understanding of the links between nutrition and muscle health. Focusing on muscle strength as the key component of sarcopenia, the aim of this overview was to evaluate its links to nutrition, both to variation in habitual diets in older populations, as well as considering supplementation effects in trials. A main message from the reviewed studies is that while many provide suggestive evidence of benefits of higher nutrient intakes and diets of higher quality, findings are inconsistent, and data on muscle strength are often lacking. To assess the potential of optimising diets as a strategy to promote and maintain muscle strength, gaps in current evidence need to be addressed. These include the need for (i) better understanding of individual differences in responsiveness to dietary change, and the need for targeted nutritional support; (ii) clearer distinction between protective and therapeutic actions of diet; and (iii) definition of the role of dietary patterns and their influence on muscle strength, to allow effects of changes in food consumption to be evaluated—particularly when combined with physical activity. Development of this evidence is needed to enable translation into appropriate dietary recommendations for older populations.

Epidemiology of frailty and associated factors among older adults living in rural communities in Taiwan

Frailty is a well-known geriatric syndrome with strong adverse health impact to older people. The socio-economic status and the accessibility of health services in rural communities may increase the risk of frailty. We conducted a cross-sectional study in rural districts of New Taipei City, Taiwan, to explore the epidemiology and associated factors of frailty. Data of 1014 participants (mean age: 78.7 ± 8.0 years, 66.3 % females) were obtained with the prevalence of frailty and pre-frailty 17.6 % and 23.1 %, respectively. The mean Barthel Index was 98.5 ± 5.8, and their mean Instrumental Activities of Daily Living (IADL) were 7.2 ± 1.5. Frail older people tended perform worse in timed up-and-go tests (24.7 % in frailty and 0.4 % in robust). The mean mini-mental state examination (MMSE) score for all participants was 23.3 ± 5.1, but was lower in frail older for around 5 points. Depressive symptoms were more common in frail older persons than robust ones (31.5 % vs 14.3 %), which was similar in the nutritional status. Results of the logistic regression showed that better education, IADL and MMSE scores were protective factors against frailty. The presence of depressive symptoms, urinary incontinence, abnormal performance of TUG, and the presence of the risk for malnutrition were all independent assciated factors for frailty. In conclusion, the prevalence of frailty was higher among older adults living in rural communities that deserves specific public health attentions. Further intervention study covering special needs in rural communities is needed to promote health of older people.

Effect of Protein Supplementation on Physical Performance in Older People With Sarcopenia-A Randomized Controlled Trial

OBJECTIVES

To test the long-term effects of whey-enriched protein supplementation on muscle and physical performance.

DESIGN

A 12-month randomized controlled double blind trial with a 43-month of post-trial follow-up.

SETTING

Porvoo, Finland.

PARTICIPANTS

A total of 218 older (>74 years of age) community-dwelling people with sarcopenia.

INTERVENTION

(1) Control with no supplementation; (2) isocaloric placebo; and (3) 20 g × 2 whey-enriched protein supplementation. All participants were given instructions on home-based exercise, dietary protein, and vitamin D supplementation of 20 μg/d.

MEASUREMENTS

Physical performance was assessed by short physical performance battery and continuous summary physical performance scores. Hand grip strength and calf intracellular resistance based skeletal muscle index were measured by bioimpedance spectroscopy. The measurements were performed at 0, 6, and 12 months. The post-trial follow-up was performed by a postal questionnaire and national census record data.

RESULTS

The participants were older (75-96 years of age) and mostly women (68%). The test supplements had no significant effects on physical performance; the 12-month changes for short physical performance battery were -0.55, -.05, and 0.03 points in control, isocaloric, and protein groups (P = .17), respectively. The changes in continuous summary physical performance scores were similar between the intervention groups (P = .76). The hand grip strength decreased significantly in all intervention groups, and the 12-month changes in calf intracellular resistance-based skeletal muscle index were minor and there were no differences between the intervention groups. One-half of the patients (56%) in both supplement groups reported mild gastrointestinal adverse effects. Differences were found neither in the all-cause mortality nor physical functioning in the post-trial follow-up.

CONCLUSIONS

The whey-enriched protein supplementation in combination with low intensity home-based physical exercise did not attenuate the deterioration of muscle and physical performance in community-dwelling older people with sarcopenia.

Dietary Protein, Exercise, and Frailty Domains

Increasing awareness of the impact of frailty on elderly people resulted in research focusing on factors that contribute to the development and persistence of frailty including nutrition and physical activity. Most effort so far has been spent on understanding the association between protein intake and the physical domain of frailty. Far less is known for other domains of frailty: cognition, mood, social health and comorbidity. Therefore, in the present narrative review, we elaborate on the evidence currently known on the association between protein and exercise as well as the broader concept of frailty. Most, but not all, identified studies concluded that low protein intake is associated with a higher prevalence and incidence of physical frailty. Far less is known on the broader concept of frailty. The few studies that do look into this association find a clear beneficial effect of physical activity but no conclusions regarding protein intake can be made yet. Similar, for other important aspects of frailty including mood, cognition, and comorbidity, the number of studies are limited and results are inconclusive. Future studies need to focus on the relation between dietary protein and the broader concept of frailty and should also consider the protein source, amount and timing.

Effects of Leucine-Enriched Whey Protein Supplementation on Physical Function in Post-Hospitalized Older Adults Participating in 12-Weeks of Resistance Training Program: A Randomized Controlled Trial

Age-related strength and muscle mass loss is further increased after acute periods of inactivity. To avoid this, resistance training has been proposed as an effective countermeasure, but the additional effect of a protein supplement is not so clear. The aim of this study was to examine the effect of a whey protein supplement enriched with leucine after resistance training on muscle mass and strength gains in a post-hospitalized elderly population. A total of 28 participants were included and allocated to either protein supplementation or placebo supplementation following resistance training for 12 weeks (2 days/week). Physical function (lower and upper body strength, aerobic capacity and the Short Physical Performance Battery (SPPB) test), mini nutritional assessment (MNA) and body composition (Dual X-ray Absorptiometry) were assessed at baseline and after 12 weeks of resistance training. Both groups showed improvements in physical function after the intervention (p < 0.01), but there were no further effects for the protein group (p > 0.05). Muscle mass did not improve after resistance training in either group (p > 0.05). In conclusion, 12 weeks of resistance training are enough to improve physical function in a post-hospitalized elderly population with no further benefits for the protein-supplemented group.