Silica exposure is associated with increased risk of developing rheumatoid arthritis: results from the Swedish EIRA study

Abstract

Objective: To study the association between silica exposure and rheumatoid arthritis and how it is modified by cigarette smoking. Methods: Data were analysed from 276 male cases and 276 male controls aged 18 to 70 years, included in a Swedish population based study between May 1996 and June 2001. A case was defined as a person recently diagnosed with rheumatoid arthritis according to the ACR criteria. Controls were selected from the study base as a stratified random sample accounting for age, sex, and residency. Men with a self reported history of work with rock drilling, stone crushing, or exposure to stone dust in general were defined as silica exposed. Rheumatoid factor (RF) status among cases was recorded. Results: Silica exposed men had increased risk of rheumatoid arthritis, with an odds ratio (OR), adjusted for age, residential area, and smoking, of 2.2 (95% confidence interval, 1.2 to 3.9) among men aged 18 to 70 years, and 2.7 (1.2 to 5.8) among those aged 50 to 70 years. Men who had worked with rock drilling or stone crushing (regarded as highly exposed) had a slightly greater increase in risk of rheumatoid arthritis than silica exposed men in general, with an OR of 3.0 (1.2 to 7.6). The joint effects of silica exposure and smoking were compatible with synergy between these two exposures in the development of rheumatoid arthritis but this was not conclusive. Conclusions: Silica exposure is associated with increased risk of developing rheumatoid arthritis. This association is not explained by smoking habits.

Antinuclear Antibody and Rheumatoid Factor in Silica-Exposed Workers

“…In contrast, another study reported crystalline silica exposure as an important risk factor for rheumatoid arthritis (21).…”

Prospective Risk of Rheumatologic Disease Associated with Occupational Exposure in a Cohort of Male Construction Workers

“…10,11 In Scandinavia in particular, population-based case referent studies and linkage of census-defined occupation and hospitalization records have provided valuable insights into the potential relationships among occupational exposures, including to silica containing and other mineral dusts, and selected rheumatologic conditions, especially rheumatoid arthritis. [12][13][14][15][16][17][18][19] Sample size considerations, however, generally preclude occupationally-defined cohort investigations of rheumatologic diseases, especially conditions other than rheumatoid arthritis. A study of granite workers in Finland with more than 10,000 person years of observation that found a 70% increase risk of rheumatoid arthritis is a rare example of a cohort-based approach.…”

Circulating and Mucosal Antibodies to Citrullinated Antigens in Rheumatoid Arthritis

“…Silica dust exposure, occurring in occupations such as rock drilling and mining, is a risk factor for ACPA positive RA, and an interaction can be seen between silica and smoking [98]. Hormonal factors are implicated by the fact that women are 2-4 times more likely to develop RA than men [99], and that RA usually develops at times when sex hormone levels change, i.e.…”