Cited by 94Nutrition and Health in AgingMuscle metabolism and nutritionMuscle Physiology and Disorders

Biomarkers of muscle quality: N‐terminal propeptide of type III procollagen and C‐terminal agrin fragment responses to resistance exercise training in older adults

Open access
Fragala, Maren S., Jajtner, Adam R., Beyer, Kyle S., Townsend, Jeremy R., Emerson, Nadia S., Scanlon, Tyler C., Oliveira, Leonardo P., Hoffman, Jay R. +1 more·2014·Journal of Cachexia, Sarcopenia and Muscle

Abstract

Background: N‐terminal peptide of procollagen type III (P3NP) and C‐terminal agrin fragment (CAF) are circulating biomarkers that are related to lean body mass in older adults. P3NP is a circulating marker reflective of muscular structural remodeling while CAF is a circulating marker of neuromuscular remodeling. As resistance exercise is an established intervention that can effectively improve muscle quality, we sought to evaluate circulating biomarker changes corresponding to a resistance exercise intervention in older adults. Methods: Twenty‐three older adults (aged 61 to 85 years) were randomized into an intervention (6‐week resistance training) or control group. Resting circulating P3NP, CAF, lean body mass (LBM), muscle cross‐sectional area (CSA), muscle strength, and muscle quality were determined at baseline and after the intervention or control period by enzyme‐linked immunosorbent assay, dual‐energy X‐ray absorptiometry, ultrasound, leg extension, and relative strength, respectively. Changes in circulating biomarkers and measures of muscle mass and quality were evaluated with repeated‐measures analysis of variance; clinical interpretations were made with magnitude‐based inferences, and relationships between variables were evaluated with bivariate correlations. Results: The short‐term resistance exercise intervention was effective at improving muscle quality by 28 % (p < 0.001) despite no significant changes in lean body mass. Baseline circulating P3NP was somewhat lower in older women (4.15 ± 1.9 ng/mL) compared with older men (4.81 ± 2.1 ng/mL). The exercise intervention tended to increase circulating P3NP (baseline = 4.53 ± 1.80 to post = 4.88 ± 1.86) and was significantly correlated with changes in LBM (r = 0.422, p = 0.045). At baseline, women (3.91 ± 1.12 pg/mL) had somewhat higher circulating CAF than men (3.47 ± 1.37 pg/mL). Circulating CAF increased by 10.4 % (3.59 to 4.00 pg/ml) in older adults following 6 weeks of resistance exercise training. Changes in circulating CAF were significantly related to changes in CSA of the vastus lateralis (r = 0.542, p = 0.008). Conclusions: Assessment of P3NP and CAF from blood samples may provide minimally invasive and clinically informative measures of skeletal muscle status in older adults. Circulating CAF appears to increase in response to short‐term resistance exercise training in older adults to a clinically meaningful magnitude. Changes in circulating P3NP in response to the intervention were less clear but appear to reflect muscle hypertrophy. Further research is needed to elucidate whether P3NP, CAF, or other biomarkers can reflect muscle qualitative adaptations with larger and longer studies.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1007/s13539-013-0120-z

Cites

42 of 42 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

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?

  • Fragala et al. observed a significant correlation of the increase circulating PIIINP and the change of lean body mass.

    “In a study comparing 6‐week resistance training with a control group, Fragala et al. 39 observed a significant correlation of the increase circulating PIIINP and the change of lean body mass.”

    From A Phase 1 study for safety and pharmacokinetics of BIO101 (20‐hydroxyecdysone) in healthy young and older adults (2023) · cites this paper as [39]

    The Results report a significant correlation between baseline circulating P3NP and change in lean body mass (r = 0.422, p = 0.045) during the six-week study. They do not report that the increase in P3NP was significantly correlated with lean-body-mass change; the exercise-related increase in P3NP itself was not statistically significant. The Abstract’s wording is less precise than the Results on which measure was correlated. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

Self-check

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

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Fragala, M. S., Jajtner, A. R., Beyer, K. S., Townsend, J. R., Emerson, N. S., Scanlon, T. C., Oliveira, L. P., Hoffman, J. R., & Stout, J. R.
Affiliations
University of Central Florida (US)
Corresponding author
Fragala, Maren S.
Venue
Journal of Cachexia, Sarcopenia and Muscle
Publisher
Wiley
Published
2013-11-07
Volume
5
Issue
2
Pages
139-148
ISSN
  • 2190-5991 (ISSN-L)
  • 2190-6009
OpenAlex
W2154110829
Cited by
94
References
42
Citations by year
2026: 7 · 2025: 7 · 2024: 9 · 2023: 12 · 2022: 3 · 2021: 10 · 2020: 8 · 2019: 1 · 2018: 5 · 2017: 6 · 2016: 12 · 2015: 11 · 2014: 3
FWCI
6.03
Type
journal article
Language
en
Open access
Locations
  • Journal of Cachexia Sarcopenia and Muscle (publishedVersion, cc-by-nc)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Journal of International Crisis and Risk Communication Research (submittedVersion)
Topics
  • Health Sciences › Medicine › Physiology › Nutrition and Health in Aging
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Muscle Physiology and Disorders
Keywords
muscle quality, resistance training, older adults, circulating biomarkers, lean body mass, muscle cross-sectional area, sex differences, muscle strength, vastus lateralis, sarcopenia prevention, magnitude-based inference, muscle quality index

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.

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