Pesticide Exposure and Risk of Rheumatoid Arthritis in Licensed Male Pesticide Applicators in the Agricultural Health Study

Armando Meyer¹, Dale Sandler², Laura Beane-Freeman³, Jonathan Hoffman⁴ and Christine G. Parks⁵, ¹Occupational and Environmental Health Branch, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, ²Epidemiology Branch, NIH/NIEHS, Research Triangle Park, NC, ³Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute,, Bethesda, MD, ⁴3Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, ⁵Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Durham, NC

Meeting: 2016 ACR/ARHP Annual Meeting

Date of first publication: September 28, 2016

Keywords: environmental factors and rheumatoid arthritis (RA)

Session Information

Date: Sunday, November 13, 2016

Title: Epidemiology and Public Health I: Inflammatory Arthritis – Risk and Impact

Session Type: ACR Concurrent Abstract Session

Session Time: 4:30PM-6:00PM

Background/Purpose: Studies suggest an association between farming and risk of rheumatoid arthritis (RA), but knowledge on the role of pesticides is sparse. Two prior studies have reported use of insecticides may increase risk of RA in women, but associations of RA with specific pesticides in men and in farmers are not known.

Methods: We investigated associations between specific pesticides and RA in a cohort of licensed male pesticide applicators/farmers in the Agricultural Health Study (AHS). Of 30,316 participants enrolled in 1993-97 who completed at least one follow-up questionnaire through 2014, 358 (138 prevalent; 220 incident) cases of RA were confirmed by medical records or self-reported use of disease modifying anti-rheumatic drugs. We evaluated associations between RA and ever-use and intensity-weighted lifetime days of use for 46 pesticides with at least 5 exposed cases, comparing confirmed cases and non-cases (n=27,744) who did not self-report RA using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusted for age at enrollment, state, smoking pack-years, and education.

Results: Incident RA was associated with ever using the insecticides fonofos (OR: 1.70; 95%CI: 1.22-2.37) and carbaryl (OR: 1.51; 95%CI: 1.03-2.23), and use of the herbicide chlorimuron ethyl (OR: 1.45; 95%CI: 1.01-2.07), while overall (prevalent + incident) RA was associated with having used the insecticides terbufos (OR: 1.27; 95%CI: 1.01-1.60) and DDT (OR: 1.38; 95%CI: 1.01-1.89) and the overall insecticide class of organophosphates (OR: 1.51; 95%CI: 1.02-2.23). Statistically significant exposure-response trends were observed for incident RA, confirming the association with fonofos (trend p=0.005), and also showing associations with the insecticide toxaphene (trend p=0.02) and the herbicide atrazine (trend p=0.01). For RA cases overall, exposure-response relationships were confirmed for terbufos (trend p=0.02) and DDT (trend p=0.04), and were also observed for the herbicides alachlor (trend p=0.03) and glyphosate (trend p=0.02).

Conclusion: Our results provide evidence of associations between use of specific pesticides and risk of RA in men, including organophosphate insecticides. Our findings also replicate an association of RA risk with the organochlorine insecticide DDT, recently described in female spouses of farmer/applicators in the AHS cohort. The immunotoxic effects of pesticides are complex, and the potential role of specific pesticides in the development of RA warrants further investigation in other samples and mechanistic studies.

Disclosure: A. Meyer, None; D. Sandler, None; L. Beane-Freeman, None; J. Hoffman, None; C. G. Parks, None.

To cite this abstract in AMA style:

Meyer A, Sandler D, Beane-Freeman L, Hoffman J, Parks CG. Pesticide Exposure and Risk of Rheumatoid Arthritis in Licensed Male Pesticide Applicators in the Agricultural Health Study [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/pesticide-exposure-and-risk-of-rheumatoid-arthritis-in-licensed-male-pesticide-applicators-in-the-agricultural-health-study/. Accessed .

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