{
  "abstract": "Aging is accompanied by progressive neuromuscular junction (NMJ) degeneration. The C-terminal agrin fragment (CAF), a circulating product of agrin cleavage, has been proposed as a minimally invasive biomarker of NMJ degradation, but its relationships with neuromuscular and functional characteristics, and the influence of physical activity, remain underexplored. We studied 136 community-dwelling men aged 20-92 years (active, n=87; inactive, n=49). Serum CAF was measured by ELISA. The proportion of NCAM-positive fibers, a marker of myofiber denervation, was assessed in vastus lateralis biopsies (n=127). Neuromuscular outcomes included maximal voluntary isometric contraction (MVIC), lower-limb power, electromechanical delay (EMD), nerve conduction velocities, H/M ratio, central activation ratio, co-activation, and twitch characteristics. Functional capacity was assessed using the 6-minute walk test, alternating step test, Timed Up and Go, sit-to-stand tests, and fast gait speed. Serum CAF increased with age and was positively associated with NCAM-positive fiber proportion. Higher CAF was associated with lower MVIC, lower-limb power and poorer performance on all functional tests. CAF was associated with longer EMD in the overall cohort and in inactive men only, and with a lower H/M ratio in inactive men. No associations were found with nerve conduction velocities, central activation ratio, co-activation, or twitch amplitude. Active men had lower CAF levels than inactive men, particularly after age 70. Serum CAF is associated with age-related declines in neuromuscular and functional capacity and with NCAM-positive fiber prevalence, supporting its utility as an accessible biomarker of NMJ remodeling. Physical activity was associated with a more favorable CAF profile in older men.",
  "abstract_shown": true,
  "affiliations": [
    "Universite du Quebec a Montreal"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 12,
  "authors": [
    {
      "name": "R. Hammad"
    },
    {
      "name": "V. Marcangeli"
    },
    {
      "name": "M. Cefis"
    },
    {
      "name": "R. Chaney"
    },
    {
      "name": "K. Desjardins"
    },
    {
      "name": "J. Granet"
    },
    {
      "name": "P. Gaudreau"
    },
    {
      "name": "R. Robitaille"
    },
    {
      "name": "J. A. Morais"
    },
    {
      "name": "M. Aubertin-Leheudre"
    },
    {
      "name": "M. Belanger"
    },
    {
      "affs": [
        0
      ],
      "name": "G. Gouspillou"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/75c899rzs05m6.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.02.747348",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.09.02.747348v1.full",
  "id": "75c899rzs05m6",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.09.02.747348v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "physiology"
    ],
    [
      "openalex",
      "1312|Muscle Physiology and Disorders"
    ]
  ],
  "openalex": "W7211904742",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.09.02.747348v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/75c899rzs05m6.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:58Z",
      "native_id": "10.64898/2026.09.02.747348",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.09.02.747348v1"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "biorxiv:physiology",
      "subfield": "physiology"
    }
  ],
  "title": "Serum C-terminal agrin fragment as a biomarker of age-related neuromuscular decline in men: influence of physical activity",
  "title_text": "Serum C-terminal agrin fragment as a biomarker of age-related neuromuscular decline in men: influence of physical activity",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:58Z",
  "url": "https://research.draconitic.com/paper/75c899rzs05m6",
  "venue": "bioRxiv",
  "versions": []
}