Session Information
Date: Monday, November 11, 2019
Title: Epidemiology & Public Health Poster II: Spondyloarthritis & Connective Tissue Disease
Session Type: Poster Session (Monday)
Session Time: 9:00AM-11:00AM
Background/Purpose: Prior research suggests that growing up on a farm and contact with livestock may confer protection against developing systemic autoimmune diseases, such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We examined associations between SLE and a related disease, Sjögren’s syndrome (SS), with childhood and adult farm experience and potential exposures to livestock for licensed pesticide applicators and their spouses in the Agricultural Health Study (AHS).
Methods: Cohort participants were enrolled in 1993-1997 in North Carolina and Iowa and followed through 2015; Lupus (mostly SLE) and SS cases were identified based on self-report and classified as “confirmed” by medical records or “clinical” based on reported use of disease-specific anti-rheumatic drugs. Our analysis sample included 214 participants with confirmed or clinical SLE/SS, with 107 incident cases (N=45 confirmed SLE or lupus with DMARD use, with or without SS, 34 primary SS, and 20 SS with RA), and a comparison group of participants (n=54,205) who did not report a systemic autoimmune disease. Farming exposures were self-reported at enrollment, while data on childhood farm animal contact were collected from 68% of the sample during follow-up. We estimated odds ratios (OR) and 95% Confidence Intervals (CI) using logistic regression models adjusted for age, sex and state for cases, overall and stratified by sex, and in sensitivity analyses excluding RA.
Results: Cases were more likely to be female (83% versus 48% of non-cases; age-adjusted OR=5.3; 95%CI 3.7, 7.6), especially for prevalent (88% female; OR=7.8; 95%CI 4.4, 13.9) and less so for incident cases (77% female; age-adj OR=3.9; 95%CI 2.5, 6.2). Childhood farm residence (at least half the time up to age 18) was inversely associated with risk of becoming a case, overall, (OR=0.46; 95%CI 0.31, 0.69) and in models limited to women (OR=0.59; 95%CI 0.39, 0.91). Incident cases were less likely to live or work on a farm that raised livestock as well as crops compared with those who only raised crops, though the association was not statistically significant (OR=0.72; 95%CI 0.48, 1.09, p=0.12). Among women, however, incident cases were significantly less likely to live or work on a farm that raised 500 or more livestock animals (OR=0.50;95%CI 0.27, 0.92), with inverse associations also seen for women on farms raising hogs, field corn, and hay (all with p< 0.05).
Conclusion: These preliminary results support the idea that exposures related to childhood farm residence and livestock farming may decrease susceptibility to developing SLE and SS. While our analyses are limited by the low frequency of SLE/SS in the cohort, especially in men, they are consistent with prior findings for RA in female spouses in the AHS. Further analyses will explore associations of SLE/SS with other agricultural exposures, including pesticides.
To cite this abstract in AMA style:
Parks C, Long S, Beane-Freeman L, Jonathan H, Dale S. Systemic Lupus Erythematosus and Sjögren’s Syndrome in the Agricultural Health Study: Lower Risk Associated with Childhood Farm Residence and Raising Livestock [abstract]. Arthritis Rheumatol. 2019; 71 (suppl 10). https://acrabstracts.org/abstract/systemic-lupus-erythematosus-and-sjogrens-syndrome-in-the-agricultural-health-study-lower-risk-associated-with-childhood-farm-residence-and-raising-livestock/. Accessed .« Back to 2019 ACR/ARP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/systemic-lupus-erythematosus-and-sjogrens-syndrome-in-the-agricultural-health-study-lower-risk-associated-with-childhood-farm-residence-and-raising-livestock/