{
  "abstract": "Acute glucose-stimulated {beta}-cell secretion is a key dimension of {beta}-cell function, but the hyperglycemic clamp used to assess it is technically demanding and resource-intensive, limiting its use at scale. We aimed to develop and validate the oral glucose tolerance test (OGTT) Early C-peptide (OEC) Index for estimating clamp-derived acute C-peptide response to glucose (ACPRg). We defined OEC as the 0-60-min incremental C-peptide area under the curve (AUC) normalized to the geometric mean of incremental and total glucose AUCs, with a fasting-glucose correction of 100/G. OEC was evaluated in paired OGTT-clamp data from RISE Adult Medication (baseline n=257; internal validation) and BetaFat (baseline n=70; external validation). Predictive R{superscript 2} and Pearson r for log-ACPRg were assessed using participant-level 5-fold cross-validation in RISE and external validation without refitting in BetaFat, with the C-peptidogenic, insulinogenic, and CIR30 indices as comparators. In RISE Adult, cross-validated R{superscript 2} for OEC was 0.47, 0.61, and 0.54 at baseline, 12, and 15 months, respectively, with corresponding Pearson r of 0.69, 0.78, and 0.74; nested cross-validation showed only modest attenuation. Applied without refitting in BetaFat, OEC yielded R{superscript 2} of 0.55, 0.41, and 0.39 at baseline, 12, and 24 months, with corresponding r of 0.76, 0.70, and 0.64. OEC had higher predictive R{superscript 2} point estimates than all three comparators at every visit in both cohorts. OEC provides a simple, transparent OGTT-based estimate of acute {beta}-cell secretory capacity that retained predictive performance in BetaFat and may broaden access to physiological assessment of early {beta}-cell function.",
  "abstract_shown": true,
  "affiliations": [
    "Wayne State University"
  ],
  "article_type": "PUBLISHAHEADOFPRINT",
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "R. Zhang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5wcacmjgz2745.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.10.05.26364738",
  "fulltext_url": "https://www.medrxiv.org/content/10.64898/2026.10.05.26364738v1.full",
  "id": "5wcacmjgz2745",
  "issns": [],
  "landing_url": "https://www.medrxiv.org/content/10.64898/2026.10.05.26364738v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "medrxiv",
      "endocrinology"
    ],
    [
      "openalex",
      "2746|Pancreatic function and diabetes"
    ]
  ],
  "openalex": "W7220690306",
  "pdf_url": "https://www.medrxiv.org/content/10.64898/2026.10.05.26364738v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5wcacmjgz2745.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:13Z",
      "native_id": "10.64898/2026.10.05.26364738",
      "source": "medrxiv",
      "url": "https://www.medrxiv.org/content/10.64898/2026.10.05.26364738v1"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "medrxiv:endocrinology",
      "subfield": "endocrinology-metabolism"
    }
  ],
  "title": "OGTT Early C-Peptide Index for Clamp-Measured Acute Beta-Cell Secretory Capacity",
  "title_text": "OGTT Early C-Peptide Index for Clamp-Measured Acute Beta-Cell Secretory Capacity",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:13Z",
  "url": "https://research.draconitic.com/paper/5wcacmjgz2745",
  "venue": "medRxiv",
  "versions": []
}