{
  "abstract": "Aims/introduction\n\nThe association between the fasting serum C-peptide levels and diabetic polyneuropathy (DPN) in patients with type 2 diabetes remains controversial. Furthermore, the association with the electrophysiological parameters of nerve conduction studies (NCS) has not been elucidated. Therefore, we investigated whether the fasting serum C-peptide levels are associated with nerve conduction velocity (CV) and action potential amplitude (Amp) in patients with type 2 diabetes.Materials and methods\n\nThis retrospective cross-sectional study enrolled outpatients with type 2 diabetes who underwent the DPNCheck® at the Higashikurume Ekimae Clinic in Tokyo, Japan, between March 1, 2016, and June 30, 2025. Participants were categorized into tertiles according to their fasting serum C-peptide levels. Abnormal values of CV and Amp were defined as CV <46.5 m/s and Amp <10.5 μV. A logistic regression analysis was used to evaluate whether the fasting serum C-peptide levels were associated with CV and Amp abnormalities.Results\n\nOne-hundred thirty-one participants were included and stratified into tertiles based on fasting serum C-peptide levels: Tertile 1, ≤1.9 ng/mL; Tertile 2, 2.0-2.8 ng/mL; and Tertile 3, ≥2.9 ng/mL. Tertile 1 was independently associated with an abnormal Amp (odds ratio: 5.08, 95% confidence interval: 1.41-18.4), whereas no independent association was observed with an abnormal CV. Tertile 2 was not associated with an abnormal CV or Amp. Additionally, a nonlinear relationship was observed between the fasting serum C-peptide levels and an abnormal Amp.Conclusions\n\nLow fasting serum C-peptide levels were independently associated with abnormal Amp in patients with type 2 diabetes.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Pharmacotherapy, Meiji Pharmaceutical University, Kiyose City, Tokyo, Japan.",
    "Internal Medicine, Higashikurume Ekimae Clinic, Higashikurume City, Tokyo, Japan."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Taichi Muramatsu",
      "orcid": "0009-0004-6073-8522"
    },
    {
      "affs": [
        1
      ],
      "name": "Kaori Inoue-Yamamoto"
    },
    {
      "affs": [
        0
      ],
      "name": "Daisuke Yamamuro",
      "orcid": "0009-0004-8976-5057"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Akifumi Kushiyama",
      "orcid": "0000-0003-1385-7487"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2m5ms4ajc5ac8.bib",
  "cited_by": 0,
  "doi": "10.1111/jdi.70482",
  "fulltext_url": "https://europepmc.org/articles/PMC13717253",
  "id": "2m5ms4ajc5ac8",
  "issns": [
    "2040-1116",
    "2040-1124"
  ],
  "landing_url": "https://europepmc.org/article/MED/42952199",
  "language": "eng",
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Original Article"
    ],
    [
      "openalex",
      "2728|Peripheral Neuropathies and Disorders"
    ]
  ],
  "openalex": "W7224504887",
  "pdf_url": "https://europepmc.org/articles/PMC13717253?pdf=render",
  "pmcid": "PMC13717253",
  "pmid": "42952199",
  "published": "2026-10-28",
  "publisher": "Wiley",
  "ris": "https://research.draconitic.com/paper/2m5ms4ajc5ac8.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T00:20:33Z",
      "native_id": "MED:42952199",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42952199"
    },
    {
      "first_seen": "2026-11-02T12:21:36Z",
      "native_id": "PMC13717253",
      "source": "pmc",
      "url": "https://doi.org/10.1111/jdi.70482"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2728|Peripheral Neuropathies and Disorders",
      "subfield": "neurology"
    }
  ],
  "title": "The low fasting serum C-peptide level was associated with reduced sural nerve action potential amplitudes: A cross-sectional study of Japanese type 2 diabetes.",
  "title_text": "The low fasting serum C-peptide level was associated with reduced sural nerve action potential amplitudes: A cross-sectional study of Japanese type 2 diabetes.",
  "type": "peer-reviewed",
  "updated_at": "2026-11-02T12:21:36Z",
  "url": "https://research.draconitic.com/paper/2m5ms4ajc5ac8",
  "venue": "Journal of diabetes investigation",
  "versions": []
}