THURSDAY, March 3 (HealthDay News) -- Women who are exposed to insecticides at home or in the workplace have an increased risk of rheumatoid arthritis (RA), or systemic lupus erythematosus (SLE), according to a study published in the February issue of Arthritis Care & Research.
Christine G. Parks, Ph.D., from the National Institute of Environmental Health Science in Durham, N.C., and colleagues analyzed data from 76,861 postmenopausal women participating in the Women's Health Initiative Observational Study. Within this cohort, 178 women were identified as having RA, 27 had SLE, and eight had both. The frequency and duration of home or workplace insecticide use was evaluated in relation to the RA/SLE risk.
The investigators found that personal use of insecticides was associated with increased RA/SLE risk compared to women who had never used them. Risk increased based on greater frequency of insecticide use (hazard ratio [HR], 2.04 for six or more times a year) and duration of use (HR, 1.97 for 20 or more years). The increased risk was also seen with exposure to long-term use of insecticides by others (HR, 1.85 for 20 or more years), but even higher for women with a history of living or working on a farm exposed to frequent insecticide use by others (HR, 2.73 for six or more times a year).
"Our results provide new evidence of a potential role for a common environmental exposure in risk of developing autoimmune diseases," the authors write.
One author disclosed a financial relationship with Merck/Schering-Plough.