Smokeless Tobacco (Moist Snuff) Use and the Risk of Developing Rheumatoid Arthritis: Results From a Case-Control Study

Objective. To investigate the association between snuff use (smokeless tobacco containing nicotine) and the risk of anti-citrullinated protein/peptide antibody (ACPA) positive and ACPA-negative rheumatoid arthritis (RA). Methods. Data from the Swedish Epidemiological Investigation of Rheumatoid Arthritis, a population-based case control study including 1,998 incident cases and 2,252 randomly selected controls (matched on age, sex, and residential area) ages 18-70 years, were analyzed. Ever, current, and past moist snuff users were compared with never users. We calculated odds ratios (ORs) with 95% confidence intervals (95% Cis) by means of unconditional logistic regression models. All analyses were adjusted for cigarette smoking, alcohol consumption, and the matching variables. Results. In total, 254 (13%) cases were ever moist snuff users compared with 290 (13%) controls, resulting in an OR of 1.0 (95% CI 0.8-1.2) of RA overall. When exposure to moist snuff was analyzed in relation to ACPA-positive and ACPA-negative disease, no associations were observed. Neither current nor past moist snuff use was related to the risk of any of the 2 RA subgroups. Analyses restricted to never smokers provided similar results. Conclusion. The use of moist snuff was not associated with the risk of either ACPA-positive or ACPA-negative RA. The increased risk of RA associated with smoking is most probably not due to nicotine.