CoChat
Sign Up
Cited by 189Nutrition and Health in AgingMuscle metabolism and nutritionFrailty in Older Adults

The Role of Muscle Mass Gain Following Protein Supplementation Plus Exercise Therapy in Older Adults with Sarcopenia and Frailty Risks: A Systematic Review and Meta-Regression Analysis of Randomized Trials

Open access
Liao, Chun-De, Chen, Hung-Chou, Huang, Shih-Wei, Liou, Tsan-Hon·2019·Nutrients
DOI 10.3390/nu11081713PMC PMC6723070
Open this paper in CoChat — free accountOpen PDF

Abstract

Aging and frailty are associated with a high risk of lean mass (LM) loss, which leads to physical disability and can be effectively alleviated by protein supplementation (PS) and muscle strengthening exercise (MSE). In this study, the associations between LM gain and PS + MSE efficacy (measured using physical outcomes) in elderly patients with a high risk of sarcopenia or frailty were identified. A comprehensive search of online databases was performed to identify randomized controlled trials (RCTs) reporting the efficacy of PS + MSE in elderly patients with sarcopenia or frailty. The included RCTs were analyzed using meta-analysis and risk of bias assessment. We finally included 19 RCTs in this meta-analysis with a median (range/total) Physiotherapy Evidence Database score of 7/10 (5–9/10). The PS + MSE group exhibited significant improvements in the whole-body LM (standard mean difference (SMD) = 0.66; p < 0.00001), appendicular LM (SMD = 0.35; p < 0.00001), leg strength (SMD = 0.65; p < 0.00001), and walking capability (SMD = 0.33; p = 0.0006). Meta-regression analyses showed that changes in appendicular LM were significantly associated with the effect sizes of leg strength (β = 0.08; p = 0.003) and walking capability (β = 0.17; p = 0.04), respectively. Our findings suggest that LM gain after PS + MSE significantly contributes to the efficacy of the intervention in terms of muscle strength and physical mobility in elderly patients with a high risk of sarcopenia or frailty.

AI snapshot

Written from the paper’s full text.

TL;DR

This systematic review and meta-regression of 19 randomized trials found that protein supplementation plus muscle-strengthening exercise improved lean mass, leg strength, and walking capability in older adults at high risk of sarcopenia or frailty. Muscle mass gain, especially appendicular lean mass, was associated with greater intervention effects on leg strength and walking capability.

Key findings

  • In 19 RCTs with 1888 participants (mean age 78.7 years; range 64.0–89.2), PS + MSE significantly improved whole-body lean mass (SMD = 0.66; 95% CI 0.41–0.91; p < 0.00001; I² = 79%) and appendicular lean mass (results section: SMD = 0.40; 95% CI 0.15–0.66; p = 0.002; I² = 59%; abstract reports SMD = 0.35; p < 0.00001).
  • PS + MSE also improved leg strength (SMD = 0.65; 95% CI 0.39–0.90; p < 0.00001; I² = 62%) and walking capability (SMD = 0.33; 95% CI 0.14–0.52; p = 0.0006; I² = 39%).
  • Meta-regression showed appendicular lean mass change was significantly associated with leg strength (β = 0.08; p = 0.003) and walking capability (β = 0.17; p = 0.04); lean body mass change was associated with leg strength (β = 0.16; 95% CI 0.04–0.29; p = 0.01) but not walking capability.
  • The paper reports that an increase in lean body mass or appendicular lean mass of >2.5% may predict a positive leg strength effect, and the discussion states an increase of >2.0% to 3.0% in muscle mass predicts positive effects on leg strength and walking capability.

Methods

  • Systematic review and meta-analysis of RCTs, registered at PROSPERO (CRD42018109176), following PRISMA; searches included PubMed, EMBASE, Cochrane Library, PEDro, China knowledge resource integrated database, and Google Scholar, with no publication-year or language restriction.
  • Included 19 RCTs of older adults (mean age ≥60 years) with high risk of sarcopenia or frailty; experimental groups received protein supplementation plus muscle-strengthening exercise, and controls received placebo, protein supplementation alone, exercise alone, or no intervention.
  • Outcomes were pooled as standard mean differences using fixed- or random-effects models depending on heterogeneity; meta-regression used percent muscle mass gain as the independent variable and strength/mobility SMDs as dependent variables, controlled for age, methodological design, and follow-up duration. Risk of bias was assessed with PEDro (median 7/10; range 5–9/10).

Limitations

  • Stated: variation in protein supplement regimes (source, amount, timing) and exercise regimes (duration, volume) made it difficult to endorse a definite conclusion for any specific PS or MSE protocol.
  • Stated: some included trials had small sample sizes, and subgroup analyses had inadequate statistical power, with several subgroups containing fewer than six RCTs.
  • Evident: heterogeneity was substantial for whole-body lean mass (I² = 79%) and leg strength (I² = 62%); the abstract and results section also report different appendicular lean mass SMDs (0.35 vs 0.40), and nearly all trials had short- or medium-term follow-up, limiting long-term conclusions.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3390/nu11081713

Cites

75 of 75 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 37 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Protein supplementation plus muscle strengthening exercise significantly improved whole-body lean mass (SMD = 0.66; p < 0.00001).

    “The PS + MSE group exhibited significant improvements in the whole-body LM (standard mean difference (SMD) = 0.66; p < 0.00001)”
    • Also stated in: § 3.6. Effectiveness on Muscle Mass · plain
      “The evidence showed an overall effect on LBM with a significant SMD of 0.66 (95%CI: 0.41–0.91, p < 0.00001; I2 = 79%) favoring PS + MSE”
    Quote in the paperSubstantial claim
  • Findingown data

    No significant association was observed between lean body mass gain and the SMD of walking capability.

    “however, no significant association was observed between LBM gain and SMD of walking capability.”
    Quote in the paperSubstantial claim
  • Findingown data

    Protein supplementation plus muscle strengthening exercise significantly improved walking capability (SMD = 0.33; p = 0.0006).

    “walking capability (SMD = 0.33; p = 0.0006)”
    • Also stated in: § 3.7. Effectiveness on Muscle Strength and Physical Mobility Outcome · plain
      “Significant effects favoring PS + MSE were observed on walking capability (SMD = 0.33, 95% CI: 0.14–0.52; p = 0.0006; I2 = 39%; Figure 2 and Figure S5).”
    Quote in the paperSubstantial claim
  • Findingown data

    Protein supplementation plus muscle strengthening exercise significantly improved appendicular lean mass (SMD = 0.35; p < 0.00001) in the abstract.

    “appendicular LM (SMD = 0.35; p < 0.00001)”
    Quote in the paperSubstantial claim
  • Findingown data

    Changes in appendicular lean mass were significantly associated with the effect sizes of leg strength (β = 0.08; p = 0.003).

    “changes in appendicular LM were significantly associated with the effect sizes of leg strength (β = 0.08; p = 0.003)”
    • Also stated in: § 3.8. Associations of Muscle Mass Change with Muscle Strength and Physical Function · plain
      “ALM (β = 0.08, 95% CI: 0.04–0.13; p = 0.003; Figure 4) were significantly associated with SMDs of leg strength”
    Quote in the paperSubstantial claim
  • May combine two claims. 24
  • Classified as probably not a substantial claim. 11
  • The quote only partly states this claim. 3

  • May combine two claims.

    Findingown data

    Subgroup analyses for lean body mass showed significant subgroup differences between participant types, among participant conditions, and among intervention periods.

    “The results of subgroup analyses for LBM (Table 3) showed significant subgroup differences between participant types (I2 = 84.4%, p = 0.01), among participant conditions (I2 = 88.4%, P = 0.0002), and intervention periods (I2 = 70.8%, p = 0.03).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The meta-analysis included 19 randomized controlled trials, with a median PEDro score of 7/10 (range 5-9/10).

    “We finally included 19 RCTs in this meta-analysis with a median (range/total) Physiotherapy Evidence Database score of 7/10 (5–9/10).”
    • Also stated in: § 3.1. Trial Flow · plain
      “The final sample consisted of 19 RCTs [31,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54], which were published between 1994 and 2019.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Fifteen randomized controlled trials enrolled community-dwelling elderly individuals with frailty, sarcopenia, or mobility limitation, and four enrolled institutionalized residents.

    “Fifteen RCTs enrolled community-dwelling elderly individuals with frailty, sarcopenia, or mobility limitation [31,37,38,39,40,41,42,44,47,48,50,51,52,53,54,55], whereas the remaining four enrolled institutionalized residents [43,45,46,49].”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    A total of 1888 participants with a mean age of 78.7 years (range 64.0-89.2) were enrolled.

    “A sample consisting of a total of 1888 participants with a mean (range) age of 78.7 (64.0–89.2) years was enrolled.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    From the total sample, 738 patients received protein-type supplement in combination with muscle strengthening exercise, 556 received exercise training with or without placebo supplement, 209 received protein supplementation alone, and 385 received placebo supplement alone or no intervention.

    “From the total sample, 738 patients received a protein-type supplement in combination with MSE, 556 received exercise training with or without placebo supplement, 209 received PS alone, and 385 received placebo supplement alone or no intervention.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingcitation

    Compliance with protein supplementation was reported as 44%-100% by 13 randomized controlled trials.

    “The compliance of PS was reported as 44%–100% by 13 RCTs [37,38,39,40,42,43,44,45,48,50,51,52,53] (Table 1).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Changes in handgrip and leg strength were reported by 6 randomized controlled trials (13 comparisons) and 11 randomized controlled trials (23 comparisons), respectively.

    “Changes in the handgrip and leg strength were reported by 6 RCTs (13 comparisons) [31,37,41,50,51,52] and 11 RCTs (23 comparisons) [31,39,41,42,43,47,48,49,51,52,54], respectively.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Most included randomized controlled trials employed an intervention period of 3-6 months; three had short intervention periods of <3 months, and one had a long period of approximately 9 months.

    “Mostly all the included RCTs employed an intervention period of 3–6 months [31,38,40,41,42,44,46,47,48,49,50,51,52,53,54]; however, three RCTs had short intervention periods of <3 months [37,43,45], and one had a long period of approximately 9 months [39].”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Protein supplementation plus muscle strengthening exercise had greater effects on lean body mass, leg strength, and walking capability than did muscle strengthening exercise alone.

    “In this meta-analysis, results of subgroup analyses based on control types showed that PS + MSE had greater effects on LBM, leg strength, and walking capability than did MSE-alone control.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    All 19 included randomized controlled trials reported a short-term or medium follow-up duration of <9 months; only one had a long-term follow-up period of >12 months.

    “With respect to the follow-up duration, all the 19 included RCTs reported a short-term or medium duration of <9 months; only one RCT had a long-term follow-up period of >12 months [45].”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Egger's linear regression test did not indicate evidence of obvious reporting bias for lean body mass, leg strength, or walking capability.

    “The Egger’s linear regression test for LBM also did not indicate any evidence of obvious reporting bias among the comparisons (t = 1.28, p = 0.21) as well as leg strength (t = −0.71, p = 0.48) and walking capability (t = −1.17, p = 0.26).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Among the 19 included randomized controlled trials, 12 had high methodological quality and 7 had medium quality.

    “Among the 19 RCTs, the methodological quality of 12 was high [37,38,39,40,41,43,45,47,48,50,51,54] and that of the other seven was medium [31,42,44,46,49,52,53], with a median PEDro score of 7/10 (range 5/10 to 9/10).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The majority of included randomized controlled trials employed daily protein supplementation with amounts of extra protein ranging from 3.0 to 40.8 g/day; three used <10.0 g/day, two used >30.0 g/day, and three provided supplements immediately after exercise with amounts ranging from 7.4 to 20.0 g/session.

    “Regarding the amount of protein, the majority of the included RCTs employed daily PS with amounts of extra protein ranging from 3.0 to 40.8 g/day. Three RCTs used PS of <10.0 g/day [31,46,47], two used PS of >30.0 g/day [43,49], and three RCTs provided supplements immediately after exercise on training days with amounts of extra protein ranging from 7.4 to 20.0 g/session [40,42,44].”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    One randomized controlled trial used a long-term exercise duration of 36 weeks (108 sessions), 15 used a medium-period treatment duration of 12-24 weeks (24-116 sessions), and three used a short-period intervention of <12 weeks (16-30 sessions).

    “One RCTs used a long-term exercise duration of 36 weeks (108 sessions) [39], whereas a medium-period treatment duration of 12–24 weeks (24–116 sessions) was used by 15 RCTs [31,38,40,41,42,44,46,47,48,49,50,51,52,53,54], and the other three RCTs used a short-period intervention of <12 weeks (16–30 sessions) [37,43,45].”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Subgroup analyses for leg strength showed significant subgroup differences between participant types, among participant conditions, and among intervention periods.

    “In addition, subgroup analyses for leg strength showed significant subgroup differences between participant types (I2 = 85.2%, p = 0.009) as well as among participant conditions (I2 = 88.7%, p = 0.0001) and intervention periods (I2 = 90.5%, P < 0.0001; Table 4).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Compliance with resistance-based and multicomponent-based muscle strengthening exercise was reported as 84%-100% and 44%-81%, respectively.

    “The compliance of resistance-based and multicomponent-based MSE was reported as 84%–100% by six RCTs [41,43,48,51,52,54] and 44%–81% by six RCTs [38,39,40,42,44,47], respectively (Table 1).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Seven randomized controlled trials used resistance exercise training, 11 used a multicomponent exercise regime, and one used aerobic training with weighted walking.

    “Regarding the mode of exercise, seven RCTs used resistance exercise training [37,41,43,48,51,52,54], 11 RCTs used multicomponent exercise regime, and one used aerobic training with weighted walking [53].”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In this study, subgroup analysis based on exercise types showed that protein supplementation plus multicomponent exercise had significant effects on lean body mass and appendicular lean mass, as did protein supplementation plus resistance exercise.

    “In this study, the results of subgroup analysis based on exercise types showed that PS and multicomponent exercise had significant effects on LBM and ALM as well as PS and resistance exercise”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Changes in lean body mass or fat-free mass after protein supplementation plus muscle strengthening exercise were reported by 18 randomized controlled trials (29 comparisons), and changes in appendicular lean mass were reported by 10 randomized controlled trials (19 comparisons).

    “Changes in LBM or fat-free mass after PS + MSE were reported by 18 RCTs (29 comparisons) [31,37,38,39,40,41,42,43,45,46,47,48,49,50,51,52,53,54], and changes in ALM were reported by 10 RCTs (19 comparisons) [31,37,41,42,47,48,50,51,52,53] (Table 1).”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    In this meta-analysis, PS + MSE is beneficial for strength gain in an elderly population with high risks of sarcopenia and frailty.

    “In this meta-analysis, we obtained conflicting results showing that PS + MSE is beneficial for LM and strength gain in an elderly population with high risks of sarcopenia and frailty; furthermore, we identified that institutionalized residents appeared to achieve greater effects on LBM and leg strength in response to PS + MSE than their community-dwelling peers.”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    In this meta-analysis, PS + MSE is beneficial for lean mass (LM) gain in an elderly population with high risks of sarcopenia and frailty.

    “In this meta-analysis, we obtained conflicting results showing that PS + MSE is beneficial for LM and strength gain in an elderly population with high risks of sarcopenia and frailty; furthermore, we identified that institutionalized residents appeared to achieve greater effects on LBM and leg strength in response to PS + MSE than their community-dwelling peers.”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Interpretationown data

    Lean mass gain after protein supplementation plus muscle strengthening exercise significantly contributes to the efficacy of the intervention in terms of muscle strength and physical mobility in elderly patients with a high risk of sarcopenia or frailty.

    “The results of this study also indicated that muscle mass gains (i.e., increases in LBM or ALM) are significantly associated with improvements in physical outcomes, particularly leg strength and walking capability.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The protocol for this study was registered at PROSPERO (registration number: CRD42018109176).

    “The protocol for this study was registered at PROSPERO (registration number: CRD42018109176).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    Two authors independently searched for relevant articles, screened them, and extracted data.

    “Two authors (CDL and HCC) independently searched for relevant articles, screened them, and extracted data.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    The meta-regression analysis was controlled for age, methodological design, and follow-up duration.

    “the analysis was controlled for age, methodological design, and follow-up duration.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductown data

    All 19 included randomized controlled trials employed random allocation, similarity at baseline, between-group comparisons, and point estimates and variability.

    “Of the 19 included RCTs, all employed random allocation, similarity at the baseline, between-group comparisons, and point estimates and variability”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductown data

    Among the 19 included randomized controlled trials, four employed concealed allocation, nine incorporated subject blinding, four incorporated therapist blinding, 10 incorporated assessor blinding, 17 had adequate follow-up, and 12 employed intention-to-treat analysis.

    “in addition, four employed concealed allocation, nine incorporated subject blinding, four incorporated therapist blinding, 10 incorporated assessor blinding, 17 had adequate follow-up, and 12 employed intention-to-treat analysis.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductcitation

    Potential publication bias was investigated using visual inspection of a funnel plot and assessed by the Egger's regression asymmetry test.

    “Potential publication bias was investigated using visual inspection of a funnel plot to explore possible reporting bias [35] and was assessed by the Egger’s regression asymmetry test [36] using the SPSS, Version 20.0, statistical software (IBM, Armonk, NY, USA).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [35] Beaudreuil, 2016, An algorithm to improve knee orthosis prescription for osteoarthritis patients, Ann. Phys. Rehabil. Med. source

      Not checked in the free run.

    • cites [36] Egger, 1997, Bias in meta-analysis detected by a simple, graphical test, BMJ source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Protein supplementation plus muscle strengthening exercise exerted overall significant effects on muscle mass (lean body mass, appendicular lean mass), muscle strength, and physical mobility in elderly people with high risks of sarcopenia and frailty, regardless of follow-up duration, participant type, exercise type, and type of control group.

    “This study demonstrated that PS + MSE exerted overall significant effects on muscle mass (LBM, ALM), muscle strength, and physical mobility in elderly people with high risks of sarcopenia and frailty, regardless of follow-up duration, participant type, exercise type, and type of control group.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    No limitation was imposed on the publication year and language to minimize publication and language bias.

    “No limitation was imposed on the publication year and language to minimize publication and language bias.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    The present study was conducted by following the PRISMA guidelines.

    “The present study was conducted by following the guidelines recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis [24].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [24] Shamseer, 2015, The PRISMA-P Group. Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: Elaboration and explanation, BMJ source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    The PEDro classification scale is a valid measure of the methodological quality of clinical trials.

    “Methodological quality of all the included studies was independently assessed by two researchers in accordance with the PEDro classification scale, which is a valid measure of the methodological quality of clinical trials [26].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [26] Wu, 2014, Prevalence and associated factors of sarcopenia and severe sarcopenia in older Taiwanese living in rural community: The Tianliao Old People study 04, Geriatr. Gerontol. Int. source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductcitation

    Several subgroups, such as intervention durations for ALM, included fewer than six RCTs, which may not have adequate power for detecting differences among subgroups.

    “Finally, inadequate statistical power for subgroup analyses was noted. Several subgroups (such as intervention durations for ALM) included a small number of RCTs (less than six), which may not have adequate power for detecting differences among subgroups [71,72]; the results of such subgroup analyses should be cautiously interpreted.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [71] Borenstein, M. (2009). Notes on subgroup analyses and Meta-regression. Introduction to Meta-Analysis, John Wiley & Sons. source

      Not checked in the free run.

    • cites [72] Fu, 2011, Conducting quantitative synthesis when comparing medical interventions: AHRQ and the Effective Health Care Program, J. Clin. Epidemiol. source

      Not checked in the free run.

33 of 33

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Overall appendicular lean mass effect differs between abstract and results

    Major

    The abstract reports an overall appendicular lean mass SMD of 0.35, while the results report 0.40 for the same outcome.

  • Community-dwelling trial list includes a trial outside the final sample

    Minor

    Reference 55 appears in the list of included community-dwelling RCTs but not in the stated final sample of 19 RCTs.

  • Follow-up duration is described as both under nine and over twelve months

    Minor

    The text says all 19 trials had follow-up under nine months, then says one had follow-up over twelve months.

3 of 3

Cites

Flagged first, then by citations

2 of the 77 references couldn’t be matched to a known paper.

Cited by

Sorted by citations

Related

Authors
Liao, C.-D., Chen, H.-C., Huang, S.-W., & Liou, T.-H.
Affiliations
  • National Taiwan University (TW)
  • Taipei Medical University-Shuang Ho Hospital (TW)
Corresponding author
Liou, Tsan-Hon
ORCID
Venue
Nutrients
Publisher
MDPI AG
Published
2019-07-25
Volume
11
Issue
8
Pages
1713
ISSN
2072-6643 (ISSN-L)
DOI
10.3390/nu11081713
PMC
PMC6723070
OpenAlex
W2963088334
Cited by
189
References
77
Citations by year
2026: 22 · 2025: 19 · 2024: 26 · 2023: 39 · 2022: 30 · 2021: 33 · 2020: 16 · 2019: 4
FWCI
2.44
Type
journal article
Language
en
Open access
Licence
Locations
  • Nutrients (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Health Sciences › Medicine › Physiology › Nutrition and Health in Aging
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Geriatrics and Gerontology › Frailty in Older Adults
Keywords
sarcopenia, frailty, protein supplementation, muscle strengthening exercises, lean mass gain, appendicular lean mass, leg strength, older adults, aging, physical mobility
MeSH terms
Frailty, Age Factors, Aged, Aged, 80 and over, Body Composition, Dietary Proteins, Exercise Therapy, Female, Humans, Male, Middle Aged, Risk Factors, Geriatric Assessment, Randomized Controlled Trials as Topic, Walking, Frail Elderly, Treatment Outcome, Muscle, Skeletal, Risk Assessment, Dietary Supplements, Recovery of Function, Muscle Strength, Sarcopenia

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review