{
  "abstract": "Objective The objective of this study is to assess the association between childhood exposure to pets and farm animals and the risk of developing rheumatoid arthritis (RA) in adulthood, using data from a large prospective cohort.Methods We analysed 78 473 women from the Etude Epidémiologique auprès des femmes de la Mutuelle générale de l’Education Nationale cohort, among whom 698 incident cases of RA were identified and validated. Childhood exposure to domestic pets (cats, dogs) and farm animals, as well as the age at first exposure, was self-reported by participants using predefined categorical options (eg, never, <1 year, 1–2 years, etc). HRs were estimated using Cox models, with confounders selected via directed acyclic graphs.Results Early exposure to pets (cats/dogs) between the ages of 1 year and 2 years compared with no exposure was associated with a lower risk of RA (adjusted HR (aHR) 0.57, 95% CI 0.34 to 0.95), regardless of smoking status. However, no association was observed with pet exposure at earlier (<1 year) or later ages. Conversely, exposure to farm animals (cows, sheep, pigs) during childhood was borderline associated with an increased risk of RA (aHR 1.26, 95% CI 1.00 to 1.59), irrespective of age at exposure.Conclusion How and when children are exposed to animals could affect the risk of developing RA. Our results suggest a potential inverse association restricted to pet exposure at ages 1–2 years, but not at other ages, whereas exposure to farm animals was positively associated. These findings should be interpreted cautiously and warrant further investigation.Trial registration number NCT03285230.",
  "authors": [
    {
      "affiliations": [
        "Centre for Research in Epidemiology and Population Health (CESP), “Exposome and Heredity” Team, Université Paris-Saclay, Gif-sur-Yvette, Île-de-France, France",
        "Pediatric Rheumatology Department, Reference Center for Auto-Inflammatory Diseases and Amyloidosis (CEREMAIA), Université Paris-Saclay, AP-HP, Paris, Île-de-France, France"
      ],
      "name": "Perrine Dusser"
    },
    {
      "affiliations": [
        "Centre de Recherche en Immunologie des Maladies, Université Paris-Saclay, INSERM U1184, Le Kremlin-Bicêtre, Île-de-France, France",
        "Department of Internal Medicine, Université Paris-Cité, AP-HP, Hôpital Beaujon, Clichy, Île-de-France, France"
      ],
      "name": "Yann Nguyen"
    },
    {
      "affiliations": [
        "Centre for Research in Epidemiology and Population Health (CESP), “Exposome and Heredity” Team, Université Paris-Saclay, Gif-sur-Yvette, Île-de-France, France"
      ],
      "name": "Claire Perrin"
    },
    {
      "affiliations": [
        "Centre for Research in Epidemiology and Population Health (CESP), “Exposome and Heredity” Team, Université Paris-Saclay, Gif-sur-Yvette, Île-de-France, France"
      ],
      "name": "Pauline Frénoy"
    },
    {
      "affiliations": [
        "Rheumatology Department, AP-HP, Hôpital Bicêtre, Université Paris-Saclay, Le Kremlin Bicêtre, Île-de-France, France",
        "Center of Immunology of Viral Infections and Auto-immune Diseases (IMVA), Université Paris-Saclay, INSERM U1184, Le Kremlin Bicêtre, Île-de-France, France"
      ],
      "name": "Xavier Mariette"
    },
    {
      "affiliations": [
        "Centre for Research in Epidemiology and Population Health (CESP), “Exposome and Heredity” Team, Université Paris-Saclay, Gif-sur-Yvette, Île-de-France, France"
      ],
      "name": "Marie-Christine Boutron-Ruault"
    },
    {
      "affiliations": [
        "Équipe d’Épidémiologie Respiratoire Intégrative, CESP, Université Paris-Saclay, INSERM U1018, Gustave Roussy, Villejuif, Île-de-France, France"
      ],
      "name": "Raphaëlle Varraso"
    },
    {
      "affiliations": [
        "Centre for Research in Epidemiology and Population Health (CESP), “Exposome and Heredity” Team, Université Paris-Saclay, Gif-sur-Yvette, Île-de-France, France",
        "Department of Statistics, Computer Science, Applications “G. Parenti”, University of Florence, Florence, Tuscany, Italy"
      ],
      "name": "Gianluca Severi"
    },
    {
      "affiliations": [
        "Laboratoire Interdisciplinaire pour l’Innovation et la Recherche en Santé Orléanaise (LI2RSO), Université d’Orléans, Orléans, Centre-Val de Loire, France",
        "Rheumatology Department, CHU d’Orléans, Université d’Orléans, Orléans, Centre-Val de Loire, France"
      ],
      "name": "Carine Salliot"
    },
    {
      "affiliations": [
        "Rheumatology Department, AP-HP, Hôpital Bicêtre, Université Paris-Saclay, Le Kremlin Bicêtre, Île-de-France, France",
        "Center of Immunology of Viral Infections and Auto-immune Diseases (IMVA), Université Paris-Saclay, INSERM U1184, Le Kremlin Bicêtre, Île-de-France, France"
      ],
      "name": "Raphaele Seror"
    }
  ],
  "title": "Early-life animal and farming exposures and the risk of rheumatoid arthritis: findings from the E3N French cohort study",
  "uid": "8e743511-d62d-5e54-a281-7837785fec25"
}