{
  "abstract": "It remains uncertain whether Type 1 diabetes (T1D) is linked to the risk of breast cancer (BC), with previous epidemiological findings yielding inconsistent conclusions. This study combined evidence from observational research through meta-analysis and used a two-sample Mendelian randomization (MR) framework to assess whether T1D contributes causally to BC risk. A total of five eligible articles encompassing nine cohort studies were included in the meta-analysis. Genetic variants with strong associations to T1D were sourced from the IEU Open GWAS database (GWAS ID: ebi-a-GCST90018925). Summary-level data for BC and its estrogen receptor (ER) subtypes were obtained from the FinnGen consortium (release R12). The pooled meta-analysis showed a statistically significant inverse association between T1D and BC risk (pooled relative effect estimate = 0.91, 95% CI: 0.85-0.98, p = 0.01). MR analyses provided evidence consistent with an inverse association between genetically predicted T1D and overall BC risk (IVW HR = 0.96, 95% CI: 0.92-1.00, p = 0.033), with a similar inverse association observed for ER-positive BC (IVW HR = 0.95, 95% CI: 0.92-0.99, p = 0.013), whereas no statistically significant association was observed for ER-negative BC. Sensitivity analyses indicated stable effect estimates despite evidence of horizontal pleiotropy detected by MR-PRESSO, while the MR-Egger intercept showed no evidence of directional pleiotropy. The combined observational and genetic evidence is consistent with a possible inverse association between T1D and BC risk, particularly for ER-positive disease, whereas no significant association was observed for ER-negative BC. Further studies are warranted to confirm these findings and clarify the underlying mechanisms.",
  "abstract_shown": true,
  "affiliations": [
    "Medical Education Center of Jinan University Jinan University Guangzhou China jnu.edu.cn.",
    "Department of Breast Jiangmen Central Hospital Jiangmen China bjch.com.",
    "Department of Thyroid and Breast Surgery Guangzhou First People's Hospital Guangzhou China gzhosp.cn.",
    "School of Medicine South China University of Technology Guangzhou China scut.edu.cn."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Yi Xie",
      "orcid": "0009-0002-3576-8266"
    },
    {
      "affs": [
        1
      ],
      "name": "Qimou Lin",
      "orcid": "0009-0006-7347-3206"
    },
    {
      "affs": [
        1
      ],
      "name": "Jianhua Guan",
      "orcid": "0009-0000-5589-1769"
    },
    {
      "affs": [
        1
      ],
      "name": "Junda Li",
      "orcid": "0000-0002-9421-5525"
    },
    {
      "affs": [
        1
      ],
      "name": "Lin Yuan",
      "orcid": "0000-0002-7758-8696"
    },
    {
      "affs": [
        1
      ],
      "name": "Junhong Wen",
      "orcid": "0009-0000-3704-3862"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Bo Xu",
      "orcid": "0000-0001-6384-6685"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/b4725f9vrh7qq.bib",
  "cited_by": 0,
  "doi": "10.1155/ije/2837214",
  "fulltext_url": "https://europepmc.org/articles/PMC13740488",
  "id": "b4725f9vrh7qq",
  "issns": [
    "1687-8337",
    "1687-8345"
  ],
  "landing_url": "https://europepmc.org/article/MED/42996517",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2730|Cancer Risks and Factors"
    ]
  ],
  "openalex": "W7203885284",
  "pdf_url": "https://europepmc.org/articles/PMC13740488?pdf=render",
  "pmcid": "PMC13740488",
  "pmid": "42996517",
  "published": "2026-11-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/b4725f9vrh7qq.ris",
  "sources": [
    {
      "first_seen": "2026-11-09T15:20:34Z",
      "native_id": "MED:42996517",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42996517"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2730|Cancer Risks and Factors",
      "subfield": "oncology"
    }
  ],
  "title": "Type 1 Diabetes and Breast Cancer Risk: Evidence From an Updated Meta-Analysis and Mendelian Randomization Study.",
  "title_text": "Type 1 Diabetes and Breast Cancer Risk: Evidence From an Updated Meta-Analysis and Mendelian Randomization Study.",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T15:20:34Z",
  "url": "https://research.draconitic.com/paper/b4725f9vrh7qq",
  "venue": "International journal of endocrinology",
  "versions": []
}