TY - JOUR
T1 - Occupational exposure to asbestos and silica and risk of developing rheumatoid arthritis
T2 - Findings from a Swedish population-based case-control study
AU - Ilar, Anna
AU - Klareskog, Lars
AU - Saevarsdottir, Saedis
AU - Wiebert, Pernilla
AU - Askling, Johan
AU - Gustavsson, Per
AU - Alfredsson, Lars
N1 - Publisher Copyright:
© 2019 Author(s).
PY - 2019/7/1
Y1 - 2019/7/1
N2 - Objective Airborne agents including cigarette smoke associate with an increased risk of rheumatoid arthritis (RA). We analysed to which extent occupational exposure to asbestos and silica confers an increased risk of developing serologically defined subsets of RA. Methods This Swedish population-based case-control study enrolled incident RA cases between 1996 and 2013 (n=11 285), identified through national public authority and quality registers, as well as from the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) Study. Controls (n=1 15 249) were randomly selected from Sweden's population register and matched on sex, age, index year and county. Occupational histories were obtained from national censuses. Exposure to asbestos and silica was assessed by job-exposure matrices. Logistic regression was used to calculate ORs adjusted for age, sex, county, index year, alcohol use and smoking. Results Results showed that male workers exposed to asbestos had higher risk of seropositive RA (OR=1.2, 95% CI 1.0 to 1.4) and seronegative RA (OR=1.2, 95% CI 1.0 to 1.5) compared with unexposed workers. The risk was highest among workers exposed to asbestos from 1970, before a national ban was introduced. Male workers exposed to silica also had higher risk of RA (seropositive RA: OR=1.4, 95% CI 1.2 to 1.6; seronegative RA: OR=1.3, 95% CI 1.0 to 1.5). For the largest subset, seropositive RA, the OR increased with the number of years exposed to silica, up to OR=2.3 (95% CI 1.4 to 3.8, p for trend <0.0001). Women overall had lower ORs than men, but the duration and intensity of their exposure were lower. Conclusions In conclusion, we observed an association between asbestos exposure and risk of developing RA and extended previous findings of an association between silica exposure and RA risk, where a dose-response relationship was observed.
AB - Objective Airborne agents including cigarette smoke associate with an increased risk of rheumatoid arthritis (RA). We analysed to which extent occupational exposure to asbestos and silica confers an increased risk of developing serologically defined subsets of RA. Methods This Swedish population-based case-control study enrolled incident RA cases between 1996 and 2013 (n=11 285), identified through national public authority and quality registers, as well as from the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) Study. Controls (n=1 15 249) were randomly selected from Sweden's population register and matched on sex, age, index year and county. Occupational histories were obtained from national censuses. Exposure to asbestos and silica was assessed by job-exposure matrices. Logistic regression was used to calculate ORs adjusted for age, sex, county, index year, alcohol use and smoking. Results Results showed that male workers exposed to asbestos had higher risk of seropositive RA (OR=1.2, 95% CI 1.0 to 1.4) and seronegative RA (OR=1.2, 95% CI 1.0 to 1.5) compared with unexposed workers. The risk was highest among workers exposed to asbestos from 1970, before a national ban was introduced. Male workers exposed to silica also had higher risk of RA (seropositive RA: OR=1.4, 95% CI 1.2 to 1.6; seronegative RA: OR=1.3, 95% CI 1.0 to 1.5). For the largest subset, seropositive RA, the OR increased with the number of years exposed to silica, up to OR=2.3 (95% CI 1.4 to 3.8, p for trend <0.0001). Women overall had lower ORs than men, but the duration and intensity of their exposure were lower. Conclusions In conclusion, we observed an association between asbestos exposure and risk of developing RA and extended previous findings of an association between silica exposure and RA risk, where a dose-response relationship was observed.
KW - epidemiology
KW - rheumatoid arthritis
KW - smoking
UR - http://www.scopus.com/inward/record.url?scp=85073882331&partnerID=8YFLogxK
U2 - 10.1136/rmdopen-2019-000978
DO - 10.1136/rmdopen-2019-000978
M3 - Article
AN - SCOPUS:85073882331
SN - 2056-5933
VL - 5
JO - RMD Open
JF - RMD Open
IS - 2
M1 - e000978
ER -